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Carter WA, Pagano SS, Seewagen CL. The effects of diet-shifting from invertebrates towards fruit on the condition of autumn-migrant Catharus thrushes. Oecologia 2024; 204:559-573. [PMID: 38363323 DOI: 10.1007/s00442-024-05511-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 01/08/2024] [Indexed: 02/17/2024]
Abstract
Migration is an energetically challenging and risky life history stage for many animals, but could be supported by dietary choices en route, which may create opportunities to improve body and physiological condition. However, proposed benefits of diet shifts, such as between seasonally available invertebrates and fruits, have received limited investigation in free-living animals. We quantified diet composition and magnitude of autumn diet shifts over two time periods in two closely-related species of migratory songbirds on stopover in the northeastern U.S. (Swainson's thrush [Catharus ustulatus], long-distance migrant, N = 83; hermit thrush [C. guttatus], short-distance migrant, N = 79) and used piecewise structural equation models to evaluate the relationships among (1) migration timing, (2) dietary behavior, and (3) morphometric and physiological condition indices. Tissue isotope composition indicated that both species shifted towards greater fruit consumption. Larger shifts in recent weeks corresponded to higher body condition in Swainson's, but not hermit thrushes, and condition was more heavily influenced by capture date in Swainson's thrushes. Presence of "high-antioxidant" fruits in fecal samples was unrelated to condition in Swainson's thrushes and negatively related to multiple condition indices in hermit thrushes, possibly indicating the value of fruits during migration is related more to their energy and/or macronutrient content than antioxidant content. Our results suggest that increased frugivory during autumn migration can support condition, but those benefits might depend on migration strategy: a longer-distance, more capital-dependent migration strategy could require stricter regulation of body condition aided by increased fruit consumption.
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Affiliation(s)
- Wales A Carter
- Great Hollow Nature Preserve and Ecological Research Center, 225 State Route 37, New Fairfield, CT, 06812, USA.
| | - Susan Smith Pagano
- Thomas H. Gosnell School of Life Sciences, Rochester Institute of Technology, 84 Lomb Memorial Drive, Rochester, NY, 14623, USA
| | - Chad L Seewagen
- Great Hollow Nature Preserve and Ecological Research Center, 225 State Route 37, New Fairfield, CT, 06812, USA
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2
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Dick MF, Hobson KA, Guglielmo CG. Experimental evidence that EPA and DHA are dietary requirements in a migratory shorebird, but they do not affect muscle oxidative capacity. J Exp Biol 2024; 227:jeb246105. [PMID: 38300135 PMCID: PMC10911131 DOI: 10.1242/jeb.246105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 01/10/2024] [Indexed: 02/02/2024]
Abstract
Dietary n-3 long chain polyunsaturated fatty acids (LCPUFAs) are hypothesized to be natural doping agents in migratory shorebirds, enabling prolonged flight by increasing membrane fluidity and oxidative capacity of the flight muscles. Animals can obtain n-3 LCPUFAs from the diet or by conversion of dietary α-linolenic acid, 18:3 n-3. However, the capacity to meet n-3 LCPUFA requirements from 18:3 n-3 varies among species. Direct tests of muscle oxidative enhancement and fatty acid conversion capacity are lacking in marine shorebirds that evolved eating diets rich in n-3 LCPUFAs. We tested whether the presence and type of dietary fatty acids influence the fatty acid composition and flight muscle oxidative capacity in western sandpipers (Calidris mauri). Sandpipers were fed diets low in n-3 PUFAs, high in 18:3 n-3, or high in n-3 LCPUFAs. Dietary fatty acid composition was reflected in multiple tissues, and low intake of n-3 LCPUFAs decreased the abundance of these fatty acids in all tissues, even with a high intake of 18:3 n-3. This suggests that 18:3 n-3 cannot replace n-3 LCPUFAs, and dietary n-3 LCPUFAs are required for sandpipers. Flight muscle indicators of enzymatic oxidative capacity and regulators of lipid metabolism did not change. However, the n-3 LCPUFA diet was associated with increased FAT/CD36 mRNA expression, potentially benefitting fatty acid transport during flight. Our study suggests that flight muscle lipid oxidation is not strongly influenced by n-3 PUFA intake. The type of dietary n-3 PUFA strongly influences the abundance of n-3 LCPUFAs in the body and could still impact whole-animal performance.
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Affiliation(s)
- Morag F. Dick
- Department of Biology, Centre for Animals on the Move, Advanced Facility for Avian Research, Western University, London, ON, Canada, N6A 5B7
| | - Keith A. Hobson
- Department of Biology, Centre for Animals on the Move, Advanced Facility for Avian Research, Western University, London, ON, Canada, N6A 5B7
| | - Christopher G. Guglielmo
- Department of Biology, Centre for Animals on the Move, Advanced Facility for Avian Research, Western University, London, ON, Canada, N6A 5B7
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3
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Reid REB, Crowley BE, Haupt RJ. The prospects of poop: a review of past achievements and future possibilities in faecal isotope analysis. Biol Rev Camb Philos Soc 2023; 98:2091-2113. [PMID: 37438959 DOI: 10.1111/brv.12996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 06/29/2023] [Accepted: 06/30/2023] [Indexed: 07/14/2023]
Abstract
What can the stable isotope values of human and animal faeces tell us? This often under-appreciated waste product is gaining recognition across a variety of disciplines. Faecal isotopes provide a means of monitoring diet, resource partitioning, landscape use, tracking nutrient inputs and cycling, and reconstructing past climate and environment. Here, we review what faeces are composed of, their temporal resolution, and how these factors may be impacted by digestive physiology and efficiency. As faeces are often used to explore diet, we clarify how isotopic offsets between diet and faeces can be calculated, as well as some differences among commonly used calculations that can lead to confusion. Generally, faecal carbon isotope (δ13 C) values are lower than those of the diet, while faecal nitrogen isotope values (δ15 N) values are higher than in the diet. However, there is considerable variability both within and among species. We explore the role of study design and how limitations stemming from a variety of factors can affect both the reliability and interpretability of faecal isotope data sets. Finally, we summarise the various ways in which faecal isotopes have been applied to date and provide some suggestions for future research. Despite remaining challenges, faecal isotope data are poised to continue to contribute meaningfully to a variety of fields.
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Affiliation(s)
- Rachel E B Reid
- Department of Geosciences, Virginia Tech, 4044 Derring Hall, 926 West Campus Dr, Blacksburg, VA, 24061, USA
| | - Brooke Erin Crowley
- Department of Geosciences, University of Cincinnati, 500 Geology Physics Building, 345 Clifton Court, Cincinnati, OH, 45221-0013, USA
- Department of Anthropology, University of Cincinnati, 481 Braunstein Hall, Cincinnati, OH, 45221-0380, USA
| | - Ryan J Haupt
- National Youth Science Foundation, PO Box 3387, Charleston, WV, 25333-3387, USA
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4
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Şekercioğlu ÇH, Fullwood MJ, Cerling T, Brenes FO, Daily GC, Ehrlich PR, Chamberlain P, Newsome SD. Using stable isotopes to measure the dietary responses of Costa Rican forest birds to agricultural countryside. Front Ecol Evol 2023. [DOI: 10.3389/fevo.2023.1086616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2023] Open
Abstract
How human modification of native habitats changes the feeding patterns and nutritional ecology of tropical birds is critical to conserving avian biodiversity, but tropical bird diets are laborious to investigate using the traditional methods of diet analysis. Stable isotope analysis provides a cost-effective and efficient proxy to identify general foraging patterns, especially when dietary shifts spanning multiple trophic levels have occurred due to ecosystem disturbance or transformation. To characterize the diets of forest bird species that persist in tropical agricultural countryside, we compared feather carbon (δ13C) and nitrogen (δ15N) isotope values of four species caught and radio-tracked in a 270 hectare forest reserve, smaller forest remnants (including mature forest, secondary forest, and riparian strips), and coffee plantations in mid-elevation (ca. 800–1,400 m) southern Costa Rica. Bird habitat choice had a significant effect on diet composition as revealed by δ13C and δ15N values. Three of the four species studied showed evidence of significantly reduced consumption of invertebrates in coffee plantations, with the isotope values of two species (Tangara icterocephala and Turdus assimilis) indicating, by comparison, nearly a doubling of invertebrate consumption in forest remnants. Our results suggest that coffee plantations are deficient in invertebrates preferred by forest generalist birds that forage in both native forest remnants and coffee plantations. In this region, typical of mountainous American tropics, small forest remnants and a larger forest reserve provide critical dietary resources for native forest birds that utilize the agricultural countryside.
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5
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Navarrete L, Lübcker N, Alvarez F, Nespolo R, Sanchez-Hernandez JC, Maldonado K, Sharp ZD, Whiteman JP, Newsome SD, Sabat P. A multi-isotope approach reveals seasonal variation in the reliance on marine resources, production of metabolic water, and ingestion of seawater by two species of coastal passerine to maintain water balance. Front Ecol Evol 2023. [DOI: 10.3389/fevo.2023.1120271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
Tracing how free-ranging organisms interact with their environment to maintain water balance is a difficult topic to study for logistical and methodological reasons. We use a novel combination of triple-oxygen stable isotope analyses of water extracted from plasma (δ16O, δ17O, δ18O) and bulk tissue carbon (δ13C) and nitrogen (δ15N) isotopes of feathers and blood to estimate the proportional contribution of marine resources, seawater, and metabolic water used by two species of unique songbirds (genus Cinclodes) to maintain their water balance in a seasonal coastal environment. We also assessed the physiological adjustments that these birds use to maintain their water balance. In agreement with previous work on these species, δ13C and δ15N data show that the coastal resident and invertivore C. nigrofumosus consumes a diet rich in marine resources, while the diet of migratory C. oustaleti shifts seasonally between marine (winter) to freshwater aquatic resources (summer). Triple-oxygen isotope analysis (Δ17O) of blood plasma, basal metabolic rate (BMR), and total evaporative water loss (TEWL) revealed that ~25% of the body water pool of both species originated from metabolic water, while the rest originated from a mix of seawater and fresh water. Δ17O measurements suggest that the contribution of metabolic water tends to increase in summer in C. nigrofumosus, which is coupled with a significant increase in BMR and TEWL. The two species had similar BMR and TEWL during the austral winter when they occur sympatrically in coastal environments. We also found a positive and significant association between the use of marine resources as measured by δ13C and δ15N values and the estimated δ18O values of ingested (pre-formed) water in both species, which indicates that Cinclodes do not directly drink seawater but rather passively ingest when consuming marine invertebrates. Finally, results obtained from physiological parameters and the isotope-based estimates of marine (food and water) resource use are consistent, supporting the use of the triple-oxygen isotopes to quantify the contribution of water sources to the total water balance of free-ranging birds.
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Hoenig BD, Trevelline BK, Kautz A, Latta SC, Porter BA. Two is better than one: Coupling DNA metabarcoding and stable isotope analysis improves dietary characterizations for a riparian-obligate, migratory songbird. Mol Ecol 2022; 31:5635-5648. [PMID: 36089910 DOI: 10.1111/mec.16688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 09/01/2022] [Accepted: 09/05/2022] [Indexed: 12/24/2022]
Abstract
While an increasing number of studies are adopting molecular and chemical methods for dietary characterization, these studies often employ only one of these laboratory-based techniques; this approach may yield an incomplete, or even biased, understanding of diet due to each method's inherent limitations. To explore the utility of coupling molecular and chemical techniques for dietary characterizations, we applied DNA metabarcoding alongside stable isotope analysis to characterize the dietary niche of breeding Louisiana waterthrush (Parkesia motacilla), a migratory songbird hypothesized to preferentially provision its offspring with pollution-intolerant, aquatic arthropod prey. While DNA metabarcoding was unable to determine if waterthrush provision aquatic and terrestrial prey in different abundances, we found that specific aquatic taxa were more likely to be detected in successive seasons than their terrestrial counterparts, thus supporting the aquatic specialization hypothesis. Our isotopic analysis added greater context to this hypothesis by concluding that breeding waterthrush provisioned Ephemeroptera and Plecoptera, two pollution-intolerant, aquatic orders, in higher quantities than other prey groups, and expanded their functional trophic niche when such prey were not abundantly provisioned. Finally, we found that the dietary characterizations from each approach were often uncorrelated, indicating that the results gleaned from a diet study can be particularly sensitive to the applied methodologies. Our findings contribute to a growing body of work indicating the importance of high-quality, aquatic habitats for both consumers and their pollution-intolerant prey, while also demonstrating how the application of multiple, laboratory-based techniques can provide insights not offered by either technique alone.
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Affiliation(s)
- Brandon D Hoenig
- Department of Biological Sciences, Duquesne University, Pittsburgh, Pennsylvania, USA
| | - Brian K Trevelline
- The Cornell Laboratory of Ornithology, Cornell University, Ithaca, New York, USA.,Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA
| | - Andrea Kautz
- Powdermill Nature Reserve, Carnegie Museum of Natural History, Pittsburgh, Pennsylvania, USA
| | | | - Brady A Porter
- Department of Biological Sciences, Duquesne University, Pittsburgh, Pennsylvania, USA
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7
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Using stable isotope (δ 13C, δ 15N) values from feces and breath to infer shorebird diets. Oecologia 2022; 200:23-35. [PMID: 36123584 PMCID: PMC9547797 DOI: 10.1007/s00442-022-05257-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 09/05/2022] [Indexed: 12/03/2022]
Abstract
The use of stable isotopes of carbon (δ13C) and nitrogen (δ15N) from feces and breath offers potential as non-destructive tools to assess diets and nutrition. How stable isotope values derived from breath and feces compare with those from commonly used tissues, such as blood fractions and liver, remains uncertain, including understanding the metabolic routing of dietary nutrients. Here, we measured δ13C and δ15N from feces and δ13C of breath from captive Red-necked Stints (Calidris ruficollis) and 26 species of wild-caught migratory shorebirds (n = 259 individuals) and compared them against isotopic values from blood and feathers. For captive birds fed either cereal- or fish-based diets, differences in δ13C between feces and lipid-free diet were small, − 0.2 ± 0.5‰ and 0.1 ± 0.3‰, respectively, and differences in δ15N, − 0.7 ± 0.5‰ and − 0.5 ± 0.5‰, respectively. Hence, δ13C and δ15N values from feces can serve as proxies for ingested proteinaceous tissues and non-soluble carbohydrates because isotopic discrimination can be considered negligible. Stable isotope values in plasma and feces were strongly correlated in wild-caught shorebirds, indicating feces can be used to infer assimilated macronutrients. Breath δ13C was 1.6 ± 0.8‰ to 5.6 ± 1.2‰ lower than bulk food sources, and breath C derived from lipids was estimated at 47.5% (cereal) to 96.1% (fish), likely underlining the importance of dietary lipids for metabolism. The findings validate the use of stable isotope values of feces and breath in isotopic assays to better understand the dietary needs of shorebirds.
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Wigginton RD, Van Grootheest C, Spautz H, Grenier JL, Whitcraft CR. Stable isotope mixing models demonstrate the role of an invasive plant in wetland songbird food webs. APPLICATIONS IN PLANT SCIENCES 2022; 10:e11486. [PMID: 36034186 PMCID: PMC9400394 DOI: 10.1002/aps3.11486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 05/12/2022] [Indexed: 06/15/2023]
Abstract
PREMISE Invasive plants in wetlands are often ecosystem engineers, mediating changes in ecosystem functions like trophic support. We documented the impacts of Lepidium latifolium, an invasive plant, on the food web of omnivorous birds (Suisun song sparrows, Melospiza melodia maxillaris) in a tidal wetland of northern California, USA. METHODS We used analysis of natural abundance stable isotopes of 13C and 15N in song sparrow blood, invertebrate food sources, L. latifolium seeds, and other marsh plant seeds to inform Bayesian, concentration-dependent mixing models that predicted average song sparrow diets. RESULTS Season and plant phenology influenced food source incorporation and isotopic signatures. Song sparrows showed higher isotopic variability in the summer. The observed changes in song sparrow diets were driven by altered invertebrate communities related to seasonal L. latifolium presence and by shifts from seeds to consumption of invertebrate food sources during the breeding season in the spring and summer. DISCUSSION This study used stable isotope tools and modeling to demonstrate two mechanisms of isotopic influence by L. latifolium on omnivorous song sparrows. This study can inform site- and species-specific management strategies by demonstrating how changes to the plant community can impact entire trophic systems.
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Affiliation(s)
- Rachel D. Wigginton
- Department of Biological SciencesCalifornia State University, Long Beach1250 Bellflower Blvd., MS 9502Long BeachCalifornia90840USA
- Sacramento–San Joaquin Delta Conservancy1450 Halyard Dr., Suite 6West SacramentoCalifornia95691USA
| | - Chloe Van Grootheest
- Department of Biological SciencesCalifornia State University, Long Beach1250 Bellflower Blvd., MS 9502Long BeachCalifornia90840USA
| | - Hildie Spautz
- Department of Fish and WildlifeEcosystem Conservation DivisionP.O. Box 944209SacramentoCalifornia94244USA
| | - J. Letitia Grenier
- San Francisco Estuary Institute4911 Central Ave.RichmondCalifornia94804USA
| | - Christine R. Whitcraft
- Department of Biological SciencesCalifornia State University, Long Beach1250 Bellflower Blvd., MS 9502Long BeachCalifornia90840USA
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Chibowski P, Brzeziński M, Suska-Malawska M, Zub K. Diet/Hair and Diet/Faeces Trophic Discrimination Factors for Stable Carbon and Nitrogen Isotopes, and Hair Regrowth in the Yellow-Necked Mouse and Bank Vole. ANN ZOOL FENN 2022. [DOI: 10.5735/086.059.0115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Affiliation(s)
- Piotr Chibowski
- Faculty of Biology, Biological and Chemical Research Centre, University of Warsaw, Żwirki i Wigury 101, PL-02-089 Warsaw, Poland
| | - Marcin Brzeziński
- Faculty of Biology, Biological and Chemical Research Centre, University of Warsaw, Żwirki i Wigury 101, PL-02-089 Warsaw, Poland
| | - Małgorzata Suska-Malawska
- Faculty of Biology, Biological and Chemical Research Centre, University of Warsaw, Żwirki i Wigury 101, PL-02-089 Warsaw, Poland
| | - Karol Zub
- Mammal Research Institute, Polish Academy of Sciences, Stoczek 1, PL-17-230 Białowieża, Poland
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10
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White AF, Dawson RD. Can diet composition estimates using stable isotope analysis of feathers predict growth and condition in nestling mountain bluebirds ( Sialia currucoides)? Ecol Evol 2021; 11:15273-15288. [PMID: 34765177 PMCID: PMC8571610 DOI: 10.1002/ece3.8210] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 09/15/2021] [Accepted: 09/23/2021] [Indexed: 11/06/2022] Open
Abstract
Insectivorous birds breeding in seasonal environments provision their dependent young during periods when prey diversity and abundance vary. Consequently, the composition and nutritional value of diets parents feed to their offspring may differ within and among broods, potentially affecting the condition of nestlings. In a population of mountain bluebirds (Sialia currucoides), we used two methods to estimate diet composition for individual nestlings: direct observation of provisioning using video recordings at 5 and 9 days post-hatch, and stable isotopes of the δ13C and δ15N in nestling feathers and prey followed by analysis with mixing models. We determined the macronutrient content (% fat and lean mass) and estimated the metabolized energy from each type of prey. We evaluated whether different methods of estimating diet composition would produce similar results, and whether the types of prey nestlings ate at one or both ages affected their morphology, growth rates, or blood ketone concentration. We found that bluebirds fed their young 5 main types of prey: beetles, cicadas, grasshoppers, insect larvae, and spiders. Both observational and mixing model estimates of diet composition indicated that larvae are traded off with grasshoppers and that fewer larvae are provided to nestlings as the season progresses. In evaluating how diet influences individual growth and condition, estimates from direct observations had greater explanatory power than those from mixing models, indicating that diets rich in the most energy-dense prey (greatest fat content; cicadas and larvae) were associated with larger size and higher body condition, and faster rate of mass gain and growth of tarsus. Lower value prey had more limited, specific effects on nestlings, but may still be important dietary components. While isotopic methods produced estimates of diet composition that were generally informative, when applied to explain the growth and condition of nestlings they proved less useful.
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Affiliation(s)
- Aija F. White
- Department of Ecosystem Science and ManagementUniversity of Northern British ColumbiaPrince GeorgeBCCanada
| | - Russell D. Dawson
- Department of Ecosystem Science and ManagementUniversity of Northern British ColumbiaPrince GeorgeBCCanada
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11
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Liu A, Mazumder D, Pirozzi I, Sammut J, Booth M. The effect of dietary choline and water temperature on the contribution of raw materials to the muscle tissue of juvenile yellowtail kingfish (Seriola lalandi): An investigation using a stable isotope mixing model. Anim Feed Sci Technol 2021. [DOI: 10.1016/j.anifeedsci.2021.115087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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12
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Stanley CQ, Dudash MR, Ryder TB, Gregory Shriver W, Marra PP. Variable tropical moisture and food availability underlie mixed winter space-use strategies in a migratory songbird. Proc Biol Sci 2021; 288:20211220. [PMID: 34284621 PMCID: PMC8292764 DOI: 10.1098/rspb.2021.1220] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 06/30/2021] [Indexed: 11/20/2022] Open
Abstract
Identifying environmental correlates driving space-use strategies can be critical for predicting population dynamics; however, such information can be difficult to attain for small mobile species such as migratory songbirds. We combined radio-telemetry and high-resolution GPS tracking to examine space-use strategies under different moisture gradients for wood thrush (Hylocichla mustelina). We explored the role moisture plays in driving food abundance and, in turn, space-use strategies at a wintering site in Belize across 3 years. Individuals occupying drier habitats experienced lower food abundance and poorer body condition. Using data from our radio-tracked study population and GPS tracking from across five breeding populations, we detected low rates of overwinter site persistence across the wood thrush wintering range. Contrary to expectations, individuals in wetter habitats were more likely to engage in permanent mid-winter relocations, up to 148 km. We suggest facultative movements are instead a condition-dependent strategy that enables wintering wood thrush to locate alternative habitat as food availability declines throughout the dry season. Increased aridity is predicted across the wintering range of wood thrush, and future research should delve deeper into understanding how moisture impacts within and between season space-use dynamics and its ultimate impact on the population dynamics of this declining species.
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Affiliation(s)
- Calandra Q. Stanley
- Migratory Bird Center, Smithsonian Conservation Biology Institute, Washington, DC 20008, USA
- Graduate Program in Behaviour, Ecology, Evolution, and Systematics, University of Maryland, College Park, MD 20742, USA
- Department of Biology and McCourt School of Public Policy, Georgetown University, 37th and O Streets NW, Washington, DC 20057, USA
| | - Michele R. Dudash
- Department of Natural Resource Management, South Dakota State University, Brookings, SD 57007, USA
| | - Thomas B. Ryder
- Migratory Bird Center, Smithsonian Conservation Biology Institute, Washington, DC 20008, USA
- Bird Conservancy of the Rockies, 230 Cherry Street, Suite 150, Fort Collins, CO 80521, USA
| | - W. Gregory Shriver
- Department of Entomology and Wildlife Ecology, University of Delaware, Newark, DE 19716, USA
| | - Peter P. Marra
- Migratory Bird Center, Smithsonian Conservation Biology Institute, Washington, DC 20008, USA
- Department of Biology and McCourt School of Public Policy, Georgetown University, 37th and O Streets NW, Washington, DC 20057, USA
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13
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Freeman NE, Norris DR, Sutton AO, Strickland D, Kyser TK, Newman AEM. Early-Life Corticosterone Body Condition Influence Social Status and Survival in a Food-Caching Passerine. Integr Comp Biol 2021; 61:9-19. [PMID: 34086914 DOI: 10.1093/icb/icab038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Individuals undergo profound changes throughout their early life as they grow and transition between life-history stages. As a result, the conditions that individuals experience during development can have both immediate and lasting effects on their physiology, behavior, and, ultimately, fitness. In a population of Canada jays in Algonquin Provincial Park, Ontario, Canada, we characterized the diet composition and physiological profile of young jays at three key time points during development (nestling, pre-fledge, and pre-dispersal) by quantifying stable-carbon (δ13C) and -nitrogen (δ15N) isotopes and corticosterone concentrations in feathers. We then investigated the downstream effects of early-life diet composition, feather corticosterone, and environmental conditions on a juvenile's social status, body condition, and probability of being observed in the fall following hatch. Across the three time points, the diet of Canada jay young was composed primarily of vertebrate tissue and human food with the proportion of these food items increasing as the jays neared dispersal. Feather corticosterone concentrations also shifted across the three time points, decreasing from nestling to pre-dispersal. Dominant juveniles had elevated corticosterone concentrations in their feathers grown pre-dispersal compared with subordinates. High body condition as nestlings was associated with high body condition as juveniles and an increased probability of being observed in the fall. Together, our results demonstrate that nestling physiology and body condition influence the social status and body condition once individuals are independent, with potential long-term consequences on survival and fitness.
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Affiliation(s)
- Nikole E Freeman
- Department of Integrative Biology, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada
| | - D Ryan Norris
- Department of Integrative Biology, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada.,Nature Conservancy of Canada, 245 Eglington Avenue East, Toronto, ON M4P 3J1, Canada
| | - Alex O Sutton
- Department of Integrative Biology, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada
| | | | - T Kurt Kyser
- Queen's Facility for Isotopic Research, Department of Geological Sciences, Queen's University, 99 University Avenue, Kingston, ON K2L 3N6, Canada
| | - Amy E M Newman
- Department of Integrative Biology, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada
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14
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Seminoff JA, Komoroske LM, Amorocho D, Arauz R, Chacón‐Chaverrí D, Paz N, Dutton PH, Donoso M, Heidemeyer M, Hoeffer G, Todd Jones T, Kelez S, Lemons GE, Rguez‐Baron JM, Sampson L, Santos Baca L, Steiner T, Vejar Rubio M, Zárate P, Zavala‐Norzagaray A, Popp BN. Large‐scale patterns of green turtle trophic ecology in the eastern Pacific Ocean. Ecosphere 2021. [DOI: 10.1002/ecs2.3479] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Affiliation(s)
- Jeffrey A. Seminoff
- NOAA‐National Marine Fisheries Service Southwest Fisheries Science Center La Jolla California USA
| | - Lisa M. Komoroske
- NOAA‐National Marine Fisheries Service Southwest Fisheries Science Center La Jolla California USA
- Department of Environmental Conservation University of Massachusetts Amherst Amherst Massachusetts USA
| | - Diego Amorocho
- Centro De Investigacion Para El Manejo Ambiental y El Desarrollo Cali Colombia
| | - Randall Arauz
- Fins Attached Marine Research and Conservation Colorado Springs Colorado USA
| | | | - Nelly Paz
- Areas Costeras y Recursos Marinos Pisco Perú
| | - Peter H. Dutton
- NOAA‐National Marine Fisheries Service Southwest Fisheries Science Center La Jolla California USA
| | | | - Maike Heidemeyer
- Escuela de Biología Centro de Investigación en Biología Celular y Molecular Centro de Investigación en Ciencas del Mar y Limnología (CIMAR) Universidad de Costa Rica San Pedro Costa Rica
| | | | - T. Todd Jones
- Pacific Islands Fisheries Science Center NOAA‐National Marine Fisheries Service Honolulu Hawaii USA
| | | | - Garrett E. Lemons
- NOAA‐National Marine Fisheries Service Southwest Fisheries Science Center La Jolla California USA
| | - Juan M. Rguez‐Baron
- Universidad Autónoma de Baja California Sur La Paz Baja California Sur México
| | - Laura Sampson
- Department of Biology Universidad del Valle Cali Colombia
| | - Lucía Santos Baca
- Department of Natural Resources Centro de Investigaciones Biológicas del Noroeste La Paz México
| | - Todd Steiner
- Turtle Island Restoration Network Forest Knolls California USA
- MigraMar Forest Knolls California USA
| | - Maria Vejar Rubio
- Instituto Politécnico Nacional CIIDIR Unidad Sinaloa Guasave Sinaloa México
| | - Patricia Zárate
- MigraMar Forest Knolls California USA
- Department of Biology University of Florida Gainesville Florida USA
| | | | - Brian N. Popp
- Department of Earth Sciences University of Hawai'i at Manoa Honolulu Hawaii USA
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15
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Jenkins E, Gulka J, Yurkowski DJ, Le François NR, Wong E, Davoren GK. Isotopic Discrimination (δ 15N, δ 13C) in Captive and Wild Common Murres ( Uria aalge) and Atlantic Puffins ( Fratercula arctica). Physiol Biochem Zool 2021; 93:296-309. [PMID: 32485127 DOI: 10.1086/709460] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Studying the diet of consumers using stable isotopes provides insight into the foraging ecology of individuals and species. To accurately reconstruct the integrated diet of animals using stable isotope values, we must quantify diet-tissue discrimination factors (DTDFs), or the way in which stable isotopes in prey are incorporated into the tissues of consumers. To quantify DTDFs, controlled experiments are needed, whereby consumers are fed a constant diet. However, relatively few controlled-diet studies have been conducted for seabirds. In this study, captive adult Atlantic puffins (Fratercula arctica) and common murres (Uria aalge) were fed a two-source diet of capelin (Mallotus villosus) and Atlantic silverside (Menidia menidia) to determine the DTDFs for the cellular component of blood and plasma for both δ15N and δ13C. The DTDFs for the cellular component (Δ15N: 2.80±0.28; Δ13C: 1.21±0.22) and plasma (Δ15N: 1.72±1.03; Δ13C: -0.18±0.56) of puffins were similar to those for the cellular component (Δ15N: 2.91±0.18; Δ13C: 1.09±0.23) and plasma (Δ15N: 2.18±0.77; Δ13C: -0.70±0.18) of murres. We reconstructed the diet of wild murres and puffins breeding on the northeastern coast of Newfoundland using previously published DTDFs and estimated DTDFs from our feeding experiment. Reconstructed dietary proportions supported a priori knowledge of diet, although outputs were sensitive to the DTDF used. Despite the similarity of our DTDFs for puffins and murres, along with the similarity of our DTDFs with those of other seabird species, our sensitivity analysis revealed considerable differences among resultant dietary contributions from mixing models, further highlighting the importance of using species- and tissue-specific DTDFs to enhance knowledge in the foraging ecology of seabirds using stable isotopes.
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16
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Krylovich OA, Boeskorov GG, Shchelchkova MV, Savinetsky AB. The Trophic Position of Pleistocene and Modern Brown Bears (Ursus arctos) of Yakutia Based on Stable Isotope Analyses. BIOL BULL+ 2021. [DOI: 10.1134/s1062359020080087] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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17
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Paxton KL, Kelly JF, Pletchet SM, Paxton EH. Stable isotope analysis of multiple tissues from Hawaiian honeycreepers indicates elevational movement. PLoS One 2020; 15:e0235752. [PMID: 32667954 PMCID: PMC7363098 DOI: 10.1371/journal.pone.0235752] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 06/23/2020] [Indexed: 11/18/2022] Open
Abstract
We have limited knowledge of the patterns, causes, and prevalence of elevational migration despite observations of seasonal movements of animals along elevational gradients in montane systems worldwide. While a third of extant Hawaiian landbird species are estimated to be elevational migrants this assumption is based primarily on early naturalist's observations with limited empirical evidence. In this study, we compared stable hydrogen isotopes (δ2H) of metabolically inert (feathers) and active (blood plasma, red blood cells) tissues collected from the same individual to determine if present day populations of Hawaiian honeycreepers undergo elevational movements to track areas of seasonally high flower bloom that constitute significant food resources. We also measured stable carbon isotopes (δ13C) and stable nitrogen isotopes (δ15N) to examine potential changes in diet between time periods. We found that the majority of 'apapane (Himatione sanguinea) and Hawai'i 'amakihi (Chlorodrepanis virens) captured at high elevation, high bloom flowering sites in the fall were not year-round residents at the capture locations, but had molted their feathers at lower elevations presumably in the summer after breeding. δ2H values of feathers for all individuals sampled were higher than blood plasma isotope values after accounting for differences in tissue-specific discrimination. We did not find a difference in the propensity of elevational movement between 'apapane and Hawai'i 'amakihi, even though the 'amakihi is considered more sedentary. However, consistent with a more generalist diet, δ15N values indicated that Hawai'i 'amakihi had a more diverse diet across trophic levels than 'apapane, and a greater reliance on nectar in the fall. We demonstrate that collecting multiple tissue samples, which grow at different rates or time periods, from a single individual can provide insights into elevational movements of Hawaiian honeycreepers over an extended time period.
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Affiliation(s)
- Kristina L. Paxton
- Department of Biology, University of Hawaiʻi Hilo, Hilo, HI, United States of America
- * E-mail:
| | - Jeffery F. Kelly
- Corix Plains Institute, University of Oklahoma, Norman, OK, United States of America
- Department of Biology, University of Oklahoma, Norman, OK, United States of America
| | - Sandra M. Pletchet
- Corix Plains Institute, University of Oklahoma, Norman, OK, United States of America
| | - Eben H. Paxton
- U.S. Geological Survey Pacific Island Ecosystems Research Center, Hawaiʻi National Park, HI, United States of America
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18
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Jackson BK, Stock SL, Harris LS, Szewczak JM, Schofield LN, Desrosiers MA. River food chains lead to riparian bats and birds in two mid‐order rivers. Ecosphere 2020. [DOI: 10.1002/ecs2.3148] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Breeanne K. Jackson
- Resources Management and Science Division Yosemite National Park El Portal California 95318 USA
| | - Sarah L. Stock
- Resources Management and Science Division Yosemite National Park El Portal California 95318 USA
| | - Leila S. Harris
- Department of Wildlife, Fish, and Conservation Biology University of California Davis California 95616 USA
| | - Joseph M. Szewczak
- Department of Biological Sciences Humboldt State University Arcata California 95521 USA
| | - Lynn N. Schofield
- Resources Management and Science Division Yosemite National Park El Portal California 95318 USA
| | - Michelle A. Desrosiers
- Resources Management and Science Division Yosemite National Park El Portal California 95318 USA
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19
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González‐Carcacía JA, Herrera M. LG, Nassar JM. Dietary importance of C3 and CAM food pathways for birds in a Neotropical semiarid zone. Biotropica 2020. [DOI: 10.1111/btp.12798] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- José Antonio González‐Carcacía
- Laboratorio de Biología de Organismos Centro de Ecología Instituto Venezolano de Investigaciones Científicas Altos de Pipe Venezuela
| | - L. Gerardo Herrera M.
- Estación de Biología de Chamela Instituto de Biología Universidad Nacional Autónoma de México San Patricio México
| | - Jafet M. Nassar
- Laboratorio de Biología de Organismos Centro de Ecología Instituto Venezolano de Investigaciones Científicas Altos de Pipe Venezuela
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20
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Walter BS, DeWitte SN, Dupras T, Beaumont J. Assessment of nutritional stress in famine burials using stable isotope analysis. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2020; 172:214-226. [PMID: 32243588 DOI: 10.1002/ajpa.24054] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 12/09/2019] [Accepted: 03/16/2020] [Indexed: 12/15/2022]
Abstract
OBJECTIVES We compared δ15 N and δ13 C values from bone and dentine collagen profiles of individuals interred in famine-related and attritional burials to evaluate whether individuals in medieval London who experienced nutritional stress exhibit enriched nitrogen in bone and tooth tissue. Dentine profiles were evaluated to identify patterns that may be indicative of famine during childhood and were compared with the age of enamel hypoplasia (EH) formation to assess whether isotopic patterns of undernutrition coincide with the timing of physiological stress. MATERIALS AND METHODS δ15 N and δ13 C isotope ratios of bone collagen were obtained from individuals (n = 128) interred in attritional and famine burials from a medieval London cemetery (c. 1120-1539). Temporal sequences of δ15 N and δ13 C isotope profiles for incrementally forming dentine collagen were obtained from a subset of these individuals (n = 21). RESULTS Results indicate that individuals from attritional graves exhibit significantly higher δ15 N values but no significant differences were found between burial types for the sexes. Analyses of dentine profiles reveal that a lower proportion of famine burials exhibit stable dentine profiles and that several exhibit a pattern of opposing covariance between δ15 N and δ13 C. EH were also observed to have formed during or after the opposing covariance pattern for some individuals. CONCLUSIONS The results of this study may reflect differences in diet between burial types rather than nutritional stress. Though nutritional stress could not be definitively identified using bone and dentine collagen, the results from dentine analysis support previous observations of biochemical patterns associated with nutritional stress during childhood.
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Affiliation(s)
- Brittany S Walter
- Defense POW/MIA Accounting Agency Laboratory, Offutt AFB, Nebraska, USA
| | - Sharon N DeWitte
- University of South Carolina, Department of Anthropology, Columbia, South Carolina, USA
| | - Tosha Dupras
- University of Central Florida, Department of Anthropology, Orlando, Florida, USA
| | - Julia Beaumont
- University of Bradford, School of Archaeological and Forensic Sciences, Bradford, West Yorkshire, UK
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21
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Méndez V, Alves JA, Þórisson B, Marca A, Gunnarsson TG, Gill JA. Individual variation in migratory behavior in a subarctic partial migrant shorebird. Behav Ecol 2020. [DOI: 10.1093/beheco/araa010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Migratory behavior can differ markedly amongst individuals within populations or species. Understanding the factors influencing this variation is key to understanding how current environmental changes might influence migratory propensity and the distribution and abundance of migratory species across their range. Here, we investigate variation in migratory behavior of the partially migratory Eurasian oystercatcher (Haematopus ostralegus) population breeding in Iceland. We use the resightings of color-ringed adults and stable isotopes to determine whether individuals migrate or remain in Iceland during winter and test whether individual migratory strategies vary in relation to sex, body size, and breeding location. We also explore individual consistency in migratory strategy and test whether assortative mating with respect to strategy occurs in this population. The proportion of migrants and residents varied greatly across breeding locations but not with respect to sex or body size. Individuals were consistent in migratory strategy between years and there was no evidence of assortative mating by migratory strategy. We use these findings to explore factors underlying the evolution and maintenance of partial migration at high latitudes.
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Affiliation(s)
- Verónica Méndez
- South Iceland Research Centre, University of Iceland, Lindarbraut, Laugarvatn, Iceland
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, UK
| | - José A Alves
- South Iceland Research Centre, University of Iceland, Lindarbraut, Laugarvatn, Iceland
- Department of Biology and CESAM, University of Aveiro, Campus de Santiago, Aveiro, Portugal
| | - Böðvar Þórisson
- South Iceland Research Centre, University of Iceland, Lindarbraut, Laugarvatn, Iceland
| | - Alina Marca
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, UK
| | - Tómas G Gunnarsson
- South Iceland Research Centre, University of Iceland, Lindarbraut, Laugarvatn, Iceland
| | - Jennifer A Gill
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, UK
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22
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Ruhl PJ, Flaherty EA, Dunning JB. Using stable isotopes of plasma, red blood cells, feces, and feathers to assess mature-forest bird diet during the post-fledging period. CAN J ZOOL 2020. [DOI: 10.1139/cjz-2019-0109] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Post-fledging use of early successional habitat by mature-forest birds is well-documented, but the important trophic factors driving this association remain poorly understood. We used stable isotope analysis of plasma, red blood cells, feces, and feathers to determine foraging preferences of three mature-forest bird species captured in 8-year-old clearcuts during the post-fledging period. We did not identify a significant source contribution in any consumer tissue combination using MixSIAR posterior distributions, but the position of consumer tissues in bivariate isotope mixing space suggested that all three mature-forest bird species acted as generalist insectivores during the post-fledging period. Furthermore, estimates of the proportional contribution of fruit to the overall diet were <0.13 for all Scarlet Tanager (Piranga olivacea (J.F. Gmelin, 1789)) tissue types, despite observational evidence of frugivory. We observed significant differentiation in core-niche-space estimates between the two obligate insectivores (Worm-eating Warbler (Helmitheros vermivorum (J.F. Gmelin, 1789)) and Ovenbird (Seiurus aurocapilla (Linnaeus, 1766))), suggesting that clearcuts provided adequate habitat to support the different foraging strategies and invertebrate preferences of both species. By using tissues with short turnover rates to address post-fledging trophic associations of mature-forest birds, we provide a comparison of isotopic values of multiple consumer tissue types in this context.
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Affiliation(s)
- Patrick J. Ruhl
- Department of Forestry and Natural Resources, Purdue University, 715 West State Street, West Lafayette, IN 47907, USA
| | - Elizabeth A. Flaherty
- Department of Forestry and Natural Resources, Purdue University, 715 West State Street, West Lafayette, IN 47907, USA
- Department of Forestry and Natural Resources, Purdue University, 715 West State Street, West Lafayette, IN 47907, USA
| | - John B. Dunning
- Department of Forestry and Natural Resources, Purdue University, 715 West State Street, West Lafayette, IN 47907, USA
- Department of Forestry and Natural Resources, Purdue University, 715 West State Street, West Lafayette, IN 47907, USA
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23
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Akresh ME, King DI, Marra PP. Rainfall and habitat interact to affect the condition of a wintering migratory songbird in The Bahamas. Ecol Evol 2019; 9:8042-8061. [PMID: 31380070 PMCID: PMC6662339 DOI: 10.1002/ece3.5359] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 05/21/2019] [Indexed: 01/25/2023] Open
Abstract
On the subtropical and tropical wintering grounds of migratory birds, variation in moisture levels and habitat can influence the availability of food resources and subsequently impact overwintering birds. Using stable carbon isotopes in blood samples as a measure of moisture, we assessed the interactive effects of rainfall, vegetation, and moisture on the demographics and condition of Prairie Warblers (Setophaga discolor) wintering in The Bahamas. Carbon isotopes in Prairie Warbler blood were more depleted in taller, wetter habitats; we additionally detected novel temporal effects of rainfall on isotope values. During a winter with more rainfall, most birds maintained mass and pectoral muscle regardless of the habitat type occupied. In a winter with less rainfall, birds lost mass and pectoral muscle, and this effect was more pronounced in birds with enriched isotope values and birds that occupied drier, shorter habitat. Prairie Warblers exhibited strong patterns of sexual habitat segregation with males disproportionately observed in areas with taller vegetation and females in shorter vegetation. During the drier winter, older males had better maintenance of pectoral muscle compared to females and younger individuals. Also in the drier winter, daily rainfall patterns explained more of the variation in body condition compared to the date of capture; pectoral muscle was best explained by recent precipitation (during the previous 30 days), while size-corrected mass was more a function of longer-term (90-day) rainfall and habitat moisture. Our findings along with other studies suggest that Prairie Warblers and other migratory birds are sensitive to interactions between annual variation in winter rainfall, within-season daily rainfall patterns, and habitat quality. Increasing drought and habitat loss in the Caribbean may be having a negative impact on wintering bird populations. To best conserve Nearctic-Neotropical migratory passerines in the region, we recommend prioritizing the protection of the least drought-prone wintering areas.
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Affiliation(s)
- Michael E. Akresh
- Department of Environmental ConservationUniversity of Massachusetts AmherstAmherstMassachusetts
- Department of Environmental StudiesAntioch University New EnglandKeeneNew Hampshire
| | - David I. King
- U.S. Forest Service Northern Research StationUniversity of Massachusetts AmherstAmherstMassachusetts
| | - Peter P. Marra
- Migratory Bird CenterSmithsonian Conservation Biology InstituteWashingtonDistrict of Columbia
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24
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Kambikambi MJ, Chakona A, Kadye WT. The influence of diet composition and tissue type on the stable isotope incorporation patterns of a small-bodied southern African minnow Enteromius anoplus (Cypriniformes, Cyprinidae). RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2019; 33:613-623. [PMID: 30672616 DOI: 10.1002/rcm.8393] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 01/17/2019] [Accepted: 01/17/2019] [Indexed: 06/09/2023]
Abstract
RATIONALE In trophic ecology, the use of stable isotope data relies on the general understanding of isotope turnover rates and diet-to-tissue discrimination factors (DTDFs). Recent studies on the application of stable isotope data have shown that isotope turnover rates and DTDFs can be influenced by many factors, including diet composition and tissue type. This study investigated the influence of diet composition and tissue type on stable isotope incorporation patterns in a small-bodied African minnow, the chubbyhead barb Enteromius anoplus. METHODS The isotopic incorporation patterns of carbon (δ13 C values) and nitrogen (δ15 N values) into white muscle and caudal fin tissues of the chubbyhead barb were examined using two isotopically different diets. Controlled-diet stable isotope feeding trials using a fishmeal-based diet (diet 1) and a soya-based diet (diet 2) were conducted over a 180-day period for the chubbyhead barb. RESULTS The two diets had contrasting isotopic incorporation patterns: diet 1 was associated with progressively high δ13 C and δ15 N values, whereas diet 2 was associated with progressively low δ13 C and δ15 N values over time for both muscle and fin tissues. The δ13 C turnover rates were similar for both tissues (56 and 61 days), whereas the δ15 N turnover rates differed between fin and muscle tissue in both diets (diet 1 = 4 and 130 days, and diet 2 = 72 and 300 days, respectively). The DTDFs were similar for both tissues in diet 1 (Δ13 C: -3.96 to -2.62‰, Δ15 N: 1.98 to 2.61‰) and diet 2 (Δ13 C: 4.05 to 5.24‰, Δ15 N: 8.45 to 9.69‰). CONCLUSIONS These results suggest that fin tissue can potentially be used as an alternative for muscle tissue in food web studies with a reasonable level of error. The isotopic turnover rate and DTDFs estimates for E. anoplus, however, require consideration of diet composition because different diets may differ in their isotopic incorporation patterns.
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Affiliation(s)
- Manda J Kambikambi
- Department of Ichthyology and Fisheries Science, Rhodes University, PO Box 94, Grahamstown, 6140, South Africa
| | - Albert Chakona
- South African Institute for Aquatic Biodiversity, Private Bag 1015, Grahamstown, 6140, South Africa
| | - Wilbert T Kadye
- Department of Ichthyology and Fisheries Science, Rhodes University, PO Box 94, Grahamstown, 6140, South Africa
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25
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Buelow CA, Reside AE, Baker R, Sheaves M. Stable isotopes reveal opportunistic foraging in a spatiotemporally heterogeneous environment: Bird assemblages in mangrove forests. PLoS One 2018; 13:e0206145. [PMID: 30439959 PMCID: PMC6237324 DOI: 10.1371/journal.pone.0206145] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 10/08/2018] [Indexed: 11/19/2022] Open
Abstract
Environmental heterogeneity can foster opportunistic foraging by mobile species, resulting in generalized resource and habitat use. Determining species' food web roles is important to fully understand how ecosystems function, and stable isotopes can provide insight into the foraging ecology of bird assemblages. We investigated flexibility of food choice in mangrove bird assemblages of northeast Australia by determining whether species' carbon and nitrogen isotopic values corresponded to foraging group classification described in the literature, such as groups of species that are omnivorous or insectivorous. Subsequently, we evaluated foraging group isotopic niche size, overlap, degree of individual specialisation, and the probable proportions of coastal resources that contribute to their collective diets. We found that mangrove birds are more opportunistic when foraging than expected from previous diet studies. Importantly, relationships between the dietary diversity of species within a foraging group and isotopic niche size are spatially inconsistent, making inferences regarding foraging strategies difficult. However, quantifying individual specialisation and determining the probable relative contributions of coastal resources to the collective diet of isotope-based foraging groups can help to differentiate between specialised and generalised foraging strategies. We suggest that flexibility in mangrove bird foraging strategy occurs in response to environmental heterogeneity. A complementary approach that combines isotopic analysis with other dietary information (collated from previous diet studies using visual observation or gut content analyses) has provided useful insight to how bird assemblages partition resources in spatiotemporally heterogeneous environments.
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Affiliation(s)
- Christina A. Buelow
- College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
- Centre for Tropical Water & Aquatic Ecosystem Research (TropWATER), James Cook University, Townsville, Queensland, Australia
| | - April E. Reside
- Centre for Biodiversity and Conservation Science, The University of Queensland, Brisbane, Queensland, Australia
| | - Ronald Baker
- College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
- Centre for Tropical Water & Aquatic Ecosystem Research (TropWATER), James Cook University, Townsville, Queensland, Australia
- Dauphin Island Sea Lab, The University of South Alabama, Dauphin Island, Alabama, United States
| | - Marcus Sheaves
- College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
- Centre for Tropical Water & Aquatic Ecosystem Research (TropWATER), James Cook University, Townsville, Queensland, Australia
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26
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Guaraldo AC, Kelly JF, Marini MÂ. Independent trophic behavior and breeding success of a resident flycatcher and a coexisting migratory congener. AUSTRAL ECOL 2018. [DOI: 10.1111/aec.12660] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- André C. Guaraldo
- Programa de Pós-graduação em Ecologia e Conservaçäo; Behavioral Ecology and Ornithology Lab; Universidade de Federal do Paraná; Curitiba 81530-900 Brazil
| | - Jeffrey F. Kelly
- Department of Biology; Oklahoma Biological Survey; University of Oklahoma; Norman Oklahoma USA
| | - Miguel Â. Marini
- Departamento de Zoologia; Universidade de Brasília; Brasília DF Brazil
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27
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Silverthorn VM, Bishop CA, Jardine T, Elliott JE, Morrissey CA. Impact of flow diversion by run-of-river dams on American dipper diet and mercury exposure. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2018; 37:411-426. [PMID: 29092091 DOI: 10.1002/etc.3961] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 05/13/2017] [Accepted: 08/22/2017] [Indexed: 06/07/2023]
Abstract
Run-of-river dams produce lower greenhouse gas emissions than large hydropower projects, but there is a paucity of research on their potential ecotoxicological impacts through disruption of natural flow regimes. We used stable isotopes (δ13 C, δ15 N, δ34 S) to reconstruct diet and trace methylmercury in a predatory river-resident passerine, the American dipper (Cinclus mexicanus), at 7 regulated and 6 free-flowing mountain streams in coastal British Columbia, Canada. Assimilated diets were comparable among regulated and unregulated streams, dominated by benthic macroinvertebrates and resident freshwater fish, with negligible contributions from anadromous Pacific salmon. Although invertebrates at unregulated streams were isotopically similar along their gradient, dippers and invertebrates sampled below dams on regulated streams had 34 S-depleted tissues, suggesting increased activity of sulfate-reducing bacteria and more Hg methylation below the dams. Mercury concentrations in dipper blood (417.6 ± 74.1 standard error [SE] ng/g wet wt at regulated streams, 340.7 ± 42.7 SE ng/g wet wt at unregulated streams) and feathers (1564 .6 ± 367.2 SE ng/g dry wt regulated, 1149.0 ± 152.1 SE ng/g dry wt unregulated), however, were not significantly different between stream types. Relative to other passerines across western North America, dippers in these densely forested mountain streams experienced high mercury exposure; and one recently regulated stream supported dippers with mercury concentrations of potential toxicity concern (up to 8459.5 ng/g dry wt in feathers and 1824.6 ng/g wet wt in whole blood). Elevated mercury in dippers is likely attributable to the birds' relatively high trophic position and high regional inorganic mercury deposition; however, biogeochemical conditions in reservoirs of some regulated streams may be contributing to methylmercury production. Environ Toxicol Chem 2018;37:411-426. © 2017 SETAC.
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Affiliation(s)
| | - Christine A Bishop
- Environment and Climate Change Canada, Wildlife and Landscape Science Division, Delta, British Columbia, Canada
| | - Timothy Jardine
- School of Environment and Sustainability, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - John E Elliott
- Environment and Climate Change Canada, Wildlife and Landscape Science Division, Delta, British Columbia, Canada
| | - Christy A Morrissey
- Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
- School of Environment and Sustainability, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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Symes C, Skhosana F, Butler M, Gardner B, Woodborne S. Isotope (δ 13C, δ 15N, δ 2H) diet-tissue discrimination in African grey parrot Psittacus erithacus: implications for forensic studies. ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES 2017; 53:580-596. [PMID: 28482709 DOI: 10.1080/10256016.2017.1319832] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 02/13/2017] [Indexed: 06/07/2023]
Abstract
Diet-tissue isotopic relationships established under controlled conditions are informative for determining the dietary sources and geographic provenance of organisms. We analysed δ13C, δ15N, and non-exchangeable δ2H values of captive African grey parrot Psittacus erithacus feathers grown on a fixed mixed-diet and borehole water. Diet-feather Δ13C and Δ15N discrimination values were +3.8 ± 0.3 ‰ and +6.3 ± 0.7 ‰ respectively; significantly greater than expected. Non-exchangeable δ2H feather values (-62.4 ± 6.4 ‰) were more negative than water (-26.1 ± 2.5 ‰) offered during feather growth. There was no positive relationship between the δ13C and δ15N values of the samples along each feather with the associated samples of food offered, or the feather non-exchangeable hydrogen isotope values with δ2H values of water, emphasising the complex processes involved in carbohydrate, protein, and income water routing to feather growth. Understanding the isotopic relationship between diet and feathers may provide greater clarity in the use of stable isotopes in feathers as a tool in determining origins of captive and wild-caught African grey parrots, a species that is widespread in aviculture and faces significant threats to wild populations. We suggest that these isotopic results, determined even in controlled laboratory conditions, be used with caution.
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Affiliation(s)
- Craig Symes
- a School of Animal, Plant and Environmental Sciences , University of the Witwatersrand, Wits , Johannesburg , South Africa
| | - Felix Skhosana
- a School of Animal, Plant and Environmental Sciences , University of the Witwatersrand, Wits , Johannesburg , South Africa
| | - Mike Butler
- b iThemba LABS, Wits , Johannesburg , South Africa
| | - Brett Gardner
- c Avian Veterinary Consultant , Johannesburg , South Africa
| | - Stephan Woodborne
- a School of Animal, Plant and Environmental Sciences , University of the Witwatersrand, Wits , Johannesburg , South Africa
- b iThemba LABS, Wits , Johannesburg , South Africa
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Hughes KL, Whiteman JP, Newsome SD. The relationship between dietary protein content, body condition, and Δ15N in a mammalian omnivore. Oecologia 2017; 186:357-367. [DOI: 10.1007/s00442-017-4010-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 11/09/2017] [Indexed: 11/29/2022]
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Pinzone M, Acquarone M, Huyghebaert L, Sturaro N, Michel LN, Siebert U, Das K. Carbon, nitrogen and sulphur isotopic fractionation in captive juvenile hooded seal (Cystophora cristata): Application for diet analysis. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2017; 31:1720-1728. [PMID: 28809062 DOI: 10.1002/rcm.7955] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 08/01/2017] [Accepted: 08/01/2017] [Indexed: 06/07/2023]
Abstract
RATIONALE Intrinsic biogeochemical markers, such as stable isotope ratios of carbon, nitrogen and sulphur, are increasingly used to trace the trophic ecology of marine top predators. However, insufficient knowledge of fractionation processes in tissues continues to hamper the use of these markers. METHODS We performed a controlled feeding experiment with eight juvenile hooded seals (Cystophora cristata) that were held on a herring-based diet (Clupea harengus) for two years. Stable isotope ratios were measured via isotope ratio mass spectrometry in three of their tissues and related to values of these markers in their diet. RESULTS Diet-tissue isotope enrichment (trophic enrichment factor, TEF) values between dietary herring and seal tissues for carbon (Δ13 C) were +0.7 ‰ for red blood cells, +1.9 ‰ for hair and +1.1 ‰ for muscle. The TEFs for nitrogen trophic (Δ15 N) were +3.3 ‰ for red blood cells, +3.6 ‰ for hair and +4.3 ‰ for muscle. For sulphur, the Δ34 S values were +1.1 ‰ for red blood cells, +1.0 ‰ for hair and +0.9 ‰ for muscle. CONCLUSIONS These enrichment values were greater than those previously measured in adult seals. This increase may be related to the higher rate of protein synthesis and catabolism in growing animals. This study is the first report on sulphur isotope enrichment values for a marine mammal species.
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Affiliation(s)
- Marianna Pinzone
- Laboratory of Oceanology - MARE Centre, University of Liege, Allée du 6 Août 11, b6c, Liege, Belgium
| | - Mario Acquarone
- Norwegian College of Fishery Science, UiT - The Arctic University of Norway, Muninbakken 21, 9019, Tromsø, Norway
| | - Loreen Huyghebaert
- Laboratory of Oceanology - MARE Centre, University of Liege, Allée du 6 Août 11, b6c, Liege, Belgium
| | - Nicolas Sturaro
- Laboratory of Oceanology - MARE Centre, University of Liege, Allée du 6 Août 11, b6c, Liege, Belgium
- Functional Reef Ecology Lab, Institute of Oceanography, National Taiwan University, Taipei, Taiwan
| | - Loïc N Michel
- Laboratory of Oceanology - MARE Centre, University of Liege, Allée du 6 Août 11, b6c, Liege, Belgium
| | - Ursula Siebert
- University of Veterinary Medicine Hannover, Foundation Institute for Terrestrial and Aquatic Wildlife Research (ITAW), 25761, Büsum, Germany
| | - Krishna Das
- Laboratory of Oceanology - MARE Centre, University of Liege, Allée du 6 Août 11, b6c, Liege, Belgium
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31
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Gómez-Ramírez P, Bustnes JO, Eulaers I, Herzke D, Johnsen TV, Lepoint G, Pérez-García JM, García-Fernández AJ, Jaspers VLB. Per- and polyfluoroalkyl substances in plasma and feathers of nestling birds of prey from northern Norway. ENVIRONMENTAL RESEARCH 2017; 158:277-285. [PMID: 28662453 DOI: 10.1016/j.envres.2017.06.019] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 06/13/2017] [Accepted: 06/19/2017] [Indexed: 06/07/2023]
Abstract
Plasma samples from nestlings of two top predators, White-tailed eagle (Haliaeetus albicilla) and Northern goshawk (Accipiter gentilis) from northern Norway were analysed for a wide range of per- and polyfluoroalkyl substances (PFASs). Body feathers from the White-tailed eagles were also analysed and significant associations between specific PFASs in blood plasma and body feathers were found (0.36 <R2 < 0.67; all p < 0.05). This result suggests that analysing body feathers of White-tailed eagle could potentially be a useful non-invasive strategy to monitor PFASs exposure in nestlings of this species. White-tailed eagles showed significantly higher levels of contaminants than Northern goshawks (plasma ∑PFASs Median = 45.83 vs 17.02ngmL-1, p <0.05). The different exposure between both species seemed to be related to different dietary input, as quantified by stable carbon and nitrogen isotope analysis of body feathers. A priori, the bird of prey populations studied are not at risk for PFASs, since the levels in plasma of both species were hundreds to thousand times lower than the toxic reference values reported for predatory birds. However, further studies on larger sample sizes are needed to confirm this hypothesis since toxic thresholds for nestling birds of prey are not established.
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Affiliation(s)
- P Gómez-Ramírez
- Department of Toxicology, Faculty of Veterinary Medicine, University of Murcia, Campus de Espinardo, 30100 Murcia, Spain.
| | - J O Bustnes
- Norwegian Institute for Nature Research, The Fram Centre, 9296 Tromsø, Norway
| | - I Eulaers
- Aarhus University, 4000 Roskilde, Denmark
| | - D Herzke
- Norwegian Institute for Air Research, 9010 Tromsø, Norway
| | - T V Johnsen
- Norwegian Institute for Nature Research, The Fram Centre, 9296 Tromsø, Norway
| | - G Lepoint
- Laboratory of Oceanology, University of Liège, B6c, 4000 Liège, Belgium
| | - J M Pérez-García
- Ecology Area, Department of Applied Biology, University Miguel Hernández, 03202 Elche, Spain; Department of Animal Sciences, Faculty of Life Sciences and Engineering, University of Lleida, 25198 Lleida, Spain
| | - A J García-Fernández
- Department of Toxicology, Faculty of Veterinary Medicine, University of Murcia, Campus de Espinardo, 30100 Murcia, Spain
| | - V L B Jaspers
- Department of Biology, Norwegian University of Science and Technology (NTNU), 7024 Trondheim, Norway
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32
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Behavioral mechanisms leading to improved fitness in a subsidized predator. Oecologia 2017; 184:787-798. [PMID: 28689262 DOI: 10.1007/s00442-017-3898-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Accepted: 06/19/2017] [Indexed: 10/19/2022]
Abstract
General mechanisms underlying the distribution and fitness of synanthropic predators in human-influenced landscapes remain unclear. Under the consumer resource-matching hypothesis, synanthropes are expected to distribute themselves among habitats according to resource availability, such that densities are greater in human-subsidized habitats, but mean individual fitness is equal among habitats because of negative density dependence. However, "under-matching" to human food resources can occur, because dominant individuals exclude subordinates from subsidized habitats and realize relatively high fitness. We integrated physiological, behavioral, and demographic information to test resource-matching hypotheses in Steller's jays (Cyanocitta stelleri), a synanthropic nest predator, to understand how behavior and social systems can influence how synanthropes respond to food subsidies. Jays consumed more human foods at subsidized (park campground) sites than jays at unsubsidized (interior forest) sites based on stable isotope analyses. Jays that occurred at higher densities were in better body condition (based on feather growth bars and lipid analyses), and had greater reproductive output at subsidized than unsubsidized sites. Jays with breeding territories in subsidized sites maintained relatively small home ranges that overlapped with multiple conspecifics, and exhibited a social system where dominant individuals typically won contests over food. Thus, jays appeared to be under-matched to prevalent resource subsidies despite high densities and behaviors expected to lead to resource matching. Our results also indicate that local resource subsidies within protected areas can result in source habitats for synanthropes, potentially impacting sensitive species over broader spatial scales.
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Abstract
Stable isotope analysis of feces can provide a non-invasive method for tracking the dietary habits of nearly any mammalian species. While fecal samples are often collected for macroscopic and genetic study, stable isotope analysis can also be applied to expand the knowledge of species-specific dietary ecology. It is somewhat unclear how digestion changes the isotope ratios of animals' diets, so more controlled diet studies are needed. To date, most diet-to-feces controlled stable isotope experiments have been performed on herbivores, so in this study I analyzed the carbon and nitrogen stable isotope ratios in the diet and feces of the meerkat (Suricata suricatta), a small omnivorous mammal. The carbon trophic discrimination factor between diet and feces (Δ13Cfeces) is calculated to be 0.1 ± 1.5‰, which is not significantly different from zero, and in turn, not different than the dietary input. On the other hand, the nitrogen trophic discrimination factor (Δ15Nfeces) is 1.5 ± 1.1‰, which is significantly different from zero, meaning it is different than the average dietary input. Based on data generated in this experiment and a review of the published literature, carbon isotopes of feces characterize diet, while nitrogen isotope ratios of feces are consistently higher than dietary inputs, meaning a discrimination factor needs to be taken into account. The carbon and nitrogen stable isotope values of feces are an excellent snapshot of diet that can be used in concert with other analytical methods to better understand ecology, diets, and habitat use of mammals.
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Affiliation(s)
- Shaena Montanari
- School of GeoSciences, University of Edinburgh, Edinburgh, United Kingdom
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34
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Isotopic analysis of epidermal mucus in freshwater fishes can reveal short-time diet variations. Ecol Res 2017. [DOI: 10.1007/s11284-017-1478-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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35
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Pagani-Núñez E, Renom M, Mateos-Gonzalez F, Cotín J, Senar JC. The diet of great tit nestlings: Comparing observation records and stable isotope analyses. Basic Appl Ecol 2017. [DOI: 10.1016/j.baae.2016.11.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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36
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Rezende JCR, Sartori MMP, Sartori JR, Ducatti C, Denadai JC, Pezzato AC. Assessment of tissue development in fattening quails using the stable isotope technique. J Anim Physiol Anim Nutr (Berl) 2017; 101:e427-e435. [PMID: 28045206 DOI: 10.1111/jpn.12624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 09/19/2016] [Indexed: 11/28/2022]
Abstract
We aimed to study the behaviour of tissue renewal in blood, pectoral muscle and keel of fattening quails during their growth and adulthood through carbon-13 turnover using the stable isotope technique. Three hundred male European quails were randomly subjected to six treatments. Diets fed to animals were initially based on corn and soybean meal and were replaced at 0, 7, 14, 21, 28 and 35 days of age with diets of rice grits and soybean meal. These diets have distinct isotopic signals and over time it changes; the tissue will incorporate dietary signal, and then, we can measure the return time for each tissue in each age. Treatments were T1 (0 to 21 days), T2 (7 to 35 days), T3 (14 to 42 days), T4 (21 to 56 days), T5 (28 to 63 days) and T6 (35 to 70 days). Carbon-13 turnover in tissues of the birds at the above-mentioned time periods was calculated using the first-order exponential function. The values of half-lives were 2.6, 3.6, 5.4, 6.3, 9.0 and 9.8 days for blood and 2.0, 1.7, 4.8, 6.7, 6.9 and 6.6 days for pectoral muscle in treatments T1, T2, T3, T4, T5 and T6 respectively. The half-lives for the keel in treatments T2, T3, T4, T5 and T6 were 2.0, 5.4, 7.7, 8.9 and 15 days respectively. Thus, half-life in sampled tissues generally increased with age of birds. Initially, the tissue half-lives are influenced by growth, and at the end of the growth cycle, the breast muscle tissue was the most metabolically active in either periods, followed by blood and the keel. All tissues showed a sigmoidal growth curve, which can be confirmed by half-life as a function of age.
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Affiliation(s)
- J C R Rezende
- Veterinary Medicine and Animal Sciences School, São Paulo State University, Botucatu, Brazil
| | - M M P Sartori
- Agronomic Sciences School, São Paulo State University, Botucatu, Brazil
| | - J R Sartori
- Veterinary Medicine and Animal Sciences School, São Paulo State University, Botucatu, Brazil
| | - C Ducatti
- Institute of Biosciences, São Paulo State University, Botucatu, Brazil
| | - J C Denadai
- Agronomic Sciences School, São Paulo State University, Botucatu, Brazil
| | - A C Pezzato
- Veterinary Medicine and Animal Sciences School, São Paulo State University, Botucatu, Brazil
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37
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West EH, Henry WR, Goldenberg W, Peery MZ. Influence of food subsidies on the foraging ecology of a synanthropic species in protected areas. Ecosphere 2016. [DOI: 10.1002/ecs2.1532] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Elena H. West
- University of Wisconsin–Madison 1630 Linden Drive Madison Wisconsin 53706 USA
| | - William R. Henry
- University of California, Santa Cruz 1156 High Street Santa Cruz California 95060 USA
| | | | - M. Zachariah Peery
- University of Wisconsin–Madison 1630 Linden Drive Madison Wisconsin 53706 USA
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38
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Beltran RS, Peterson SH, McHuron EA, Reichmuth C, Hückstädt LA, Costa DP. Seals and sea lions are what they eat, plus what? Determination of trophic discrimination factors for seven pinniped species. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2016; 30:1115-1122. [PMID: 27060839 PMCID: PMC4830913 DOI: 10.1002/rcm.7539] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 01/14/2016] [Accepted: 02/14/2016] [Indexed: 06/05/2023]
Abstract
RATIONALE Mixing models are a common method for quantifying the contribution of prey sources to the diet of an individual using stable isotope analysis; however, these models rely upon a known trophic discrimination factor (hereafter, TDF) that results from fractionation between prey and animal tissues. Quantifying TDFs in captive animals is ideal, because diet is controlled and the proportional contributions and isotopic values of all prey items are known. METHODS To calculate TDFs for the Hawaiian monk seal, northern elephant seal, bearded seal, ringed seal, spotted seal, harbor seal, and California sea lion, we obtained whiskers, serum, plasma, red blood cells, and prey items from nine captive individuals. We obtained δ(13) C and δ(15) N values using continuous-flow isotope-ratio mass spectrometry. The average δ(13) C and δ(15) N values from bulk and lipid-corrected prey from the diet were subtracted from the δ(13) C and δ(15) N values of each blood and whisker sample to calculate tissue-specific TDFs for each individual (∆(13) C or ∆(15) N). RESULTS The ∆(13) C values ranged from +1.7 to +3.2‰ (bulk prey) and from +0.8 to +1.9‰ (lipid-corrected prey) for the various blood components, and from +3.9 to +4.6‰ (bulk prey) or +2.6 to +3.9‰ (lipid-corrected prey) for whiskers. The ∆(15) N values ranged from +2.2 to +4.3‰ for blood components and from +2.6 to +4.0‰ for whiskers. The TDFs tended to group by tissue, with whiskers having greater ∆(13) C values than blood components. In contrast, the ∆(15) N values were greater in serum and plasma than in red blood cells and whiskers. CONCLUSIONS By providing the first TDF values for five seal species (family Phocidae) and one otariid species (family Otariidae), our study facilitates more accurate mixing models for these species. These values are particularly important for critically endangered Hawaiian monk seals and the three Arctic seal species (bearded, ringed, and spotted) that are faced with a rapidly changing environment.
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Affiliation(s)
- Roxanne S. Beltran
- University of California, Santa Cruz, Department of Ecology & Evolutionary Biology, Santa Cruz, CA 95060, USA
| | - Sarah H. Peterson
- University of California, Santa Cruz, Department of Ecology & Evolutionary Biology, Santa Cruz, CA 95060, USA
| | - Elizabeth A. McHuron
- University of California, Santa Cruz, Department of Ecology & Evolutionary Biology, Santa Cruz, CA 95060, USA
| | - Colleen Reichmuth
- Institute of Marine Sciences, Long Marine Laboratory, Santa Cruz, CA 95060, USA
| | - Luis A. Hückstädt
- University of California, Santa Cruz, Department of Ecology & Evolutionary Biology, Santa Cruz, CA 95060, USA
| | - Daniel P. Costa
- University of California, Santa Cruz, Department of Ecology & Evolutionary Biology, Santa Cruz, CA 95060, USA
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39
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Quinn LR, Meharg AA, van Franeker JA, Graham IM, Thompson PM. Validating the use of intrinsic markers in body feathers to identify inter-individual differences in non-breeding areas of northern fulmars. MARINE BIOLOGY 2016; 163:64. [PMID: 27065496 PMCID: PMC4771816 DOI: 10.1007/s00227-016-2822-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 01/20/2016] [Indexed: 06/05/2023]
Abstract
Many wildlife studies use chemical analyses to explore spatio-temporal variation in diet, migratory patterns and contaminant exposure. Intrinsic markers are particularly valuable for studying non-breeding marine predators, when direct methods of investigation are rarely feasible. However, any inferences regarding foraging ecology are dependent upon the time scale over which tissues such as feathers are formed. In this study, we validate the use of body feathers for studying non-breeding foraging patterns in a pelagic seabird, the northern fulmar. Analysis of carcasses of successfully breeding adult fulmars indicated that body feathers moulted between September and March, whereas analyses of carcasses and activity patterns suggested that wing feather and tail feather moult occurred during more restricted periods (September to October and September to January, respectively). By randomly sampling relevant body feathers, average values for individual birds were shown to be consistent. We also integrated chemical analyses of body feather with geolocation tracking data to demonstrate that analyses of δ13C and δ15N values successfully assigned 88 % of birds to one of two broad wintering regions used by breeding adult fulmars from a Scottish study colony. These data provide strong support for the use of body feathers as a tool for exploring non-breeding foraging patterns and diet in wide-ranging, pelagic seabirds.
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Affiliation(s)
- Lucy R. Quinn
- />Institute of Biological and Environmental Sciences, University of Aberdeen, Lighthouse Field Station, Cromarty, IV11 8YJ UK
- />British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET UK
| | - Andrew A. Meharg
- />Institute for Global Food Security, Queen’s University Belfast, 18-30 Malone Road, Belfast, BT9 5BN Northern Ireland, UK
| | | | - Isla M. Graham
- />Institute of Biological and Environmental Sciences, University of Aberdeen, Lighthouse Field Station, Cromarty, IV11 8YJ UK
| | - Paul M. Thompson
- />Institute of Biological and Environmental Sciences, University of Aberdeen, Lighthouse Field Station, Cromarty, IV11 8YJ UK
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40
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Busst GMA, Britton JR. High variability in stable isotope diet-tissue discrimination factors of two omnivorous freshwater fishes in controlled ex situ conditions. ACTA ACUST UNITED AC 2016; 219:1060-8. [PMID: 26896544 DOI: 10.1242/jeb.137380] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 01/27/2016] [Indexed: 11/20/2022]
Abstract
Diet-tissue discrimination factors (Δ(13)C and Δ(15)N) are influenced by variables including the tissues being analysed and the taxon of the consumer and its prey. Whilst differences in Δ(13)C and Δ(15)N are apparent between herbivorous and piscivorous fishes, there is less known for omnivorous fishes that consume plant and animal material. Here, the omnivorous cyprinid fishes Barbus barbus and Squalius cephalus were held in tank aquaria and exposed to three diets that varied in their constituents (plant based to fishmeal based) and protein content (13% to 45%). After 100 days and isotopic replacement in fish tissues to 98%, samples of the food items, and dorsal muscle, fin tissue and scales were analysed for δ(13)C and δ(15)N. For both species and all diets, muscle was always enriched in δ(15)N and depleted in δ(13)C compared with fin tissue and scales. Across the different diets, Δ(13)C ranged between 2.0‰ and 5.6‰ and Δ(15)N ranged between 2.0‰ and 6.9‰. The diet based on plant material (20% protein) always resulted in the highest discrimination factors for each tissue, whilst the diet based on fishmeal (45% protein) consistently resulted in the lowest. The discrimination factors produced by non-fish diets were comparatively high compared with values in the literature, but were consistent with general patterns for some herbivorous fishes. These outputs suggest that the diet-tissue discrimination factors of omnivorous fishes will vary considerably between animal and plant prey, and these specific differences need consideration in predictions of their diet composition and trophic position.
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Affiliation(s)
- Georgina M A Busst
- Department of Life and Environmental Sciences, Faculty of Science and Technology, Bournemouth University, Poole BH12 5BB, UK
| | - J Robert Britton
- Department of Life and Environmental Sciences, Faculty of Science and Technology, Bournemouth University, Poole BH12 5BB, UK
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41
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Herrera M. LG, Osorio M. J. Tracking Nutrient Routing in Avian Consumers in a Subtropical Desert. Biotropica 2016. [DOI: 10.1111/btp.12274] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- L. Gerardo Herrera M.
- Estación de Biología de Chamela; Instituto de Biología; Universidad Nacional Autónoma de México; Apartado Postal 21 San Patricio Jalisco 48980 Mexico
| | - Jazmín Osorio M.
- Departamento de Ecología y Recursos Naturales; Centro Universitario de la Costa Sur; Universidad de Guadalajara; Av. Independencia Nacional #151 Autlán Jalisco 48900 Mexico
- Facultad de Ciencias Biológicas y Agropecuarias; Autopista Colima-Manzanillo km 40 Crucero de Tecomán; Tecomán Colima 28100 Mexico
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42
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van Gils JA, Ahmedou Salem MV. Validating the Incorporation of 13C and 15N in a Shorebird That Consumes an Isotopically Distinct Chemosymbiotic Bivalve. PLoS One 2015; 10:e0140221. [PMID: 26458005 PMCID: PMC4601768 DOI: 10.1371/journal.pone.0140221] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2015] [Accepted: 09/23/2015] [Indexed: 11/18/2022] Open
Abstract
The wealth of field studies using stable isotopes to make inferences about animal diets require controlled validation experiments to make proper interpretations. Despite several pleas in the literature for such experiments, validation studies are still lagging behind, notably in consumers dwelling in chemosynthesis-based ecosystems. In this paper we present such a validation experiment for the incorporation of 13C and 15N in the blood plasma of a medium-sized shorebird, the red knot (Calidris canutus canutus), consuming a chemosymbiotic lucinid bivalve (Loripes lucinalis). Because this bivalve forms a symbiosis with chemoautotrophic sulphide-oxidizing bacteria living inside its gill, the bivalve is isotopically distinct from 'normal' bivalves whose food has a photosynthetic basis. Here we experimentally tested the hypothesis that isotope discrimination and incorporation dynamics are different when consuming such chemosynthesis-based prey. The experiment showed that neither the isotopic discrimination factor, nor isotopic turnover time, differed between birds consuming the chemosymbiotic lucinid and a control group consuming a photosynthesis-based bivalve. This was true for 13C as well as for 15N. However, in both groups the 15N discrimination factor was much higher than expected, which probably had to do with the birds losing body mass over the course of the experiment.
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Affiliation(s)
- Jan A. van Gils
- NIOZ Royal Netherlands Institute for Sea Research, 1790 AB Den Burg, The Netherlands
- * E-mail:
| | - Mohamed Vall Ahmedou Salem
- EBIOME Ecobiologie Marine et Environnement, Département de Biologie, Université des Sciences, de Technologie et de Médecine, B.P. 880, Nouakchott, Mauritania
- Laboratoire de Biologie Appliquée et Pathologie, Département de Biologie, Faculté des Science, B.P. 2121, Tetouan, Morocco
- Parc National du Banc d’Arguin, B.P. 5355, Nouakchott, Mauritania
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Jesus FM, Pereira MR, Rosa CS, Moreira MZ, Sperber CF. Preservation Methods Alter Carbon and Nitrogen Stable Isotope Values in Crickets (Orthoptera: Grylloidea). PLoS One 2015; 10:e0137650. [PMID: 26390400 PMCID: PMC4577105 DOI: 10.1371/journal.pone.0137650] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 08/20/2015] [Indexed: 11/18/2022] Open
Abstract
Stable isotope analysis (SIA) is an important tool for investigation of animal dietary habits for determination of feeding niche. Ideally, fresh samples should be used for isotopic analysis, but logistics frequently demands preservation of organisms for analysis at a later time. The goal of this study was to establish the best methodology for preserving forest litter-dwelling crickets for later SIA analysis without altering results. We collected two cricket species, Phoremia sp. and Mellopsis doucasae, from which we prepared 70 samples per species, divided among seven treatments: (i) freshly processed (control); preserved in fuel ethanol for (ii) 15 and (iii) 60 days; preserved in commercial ethanol for (iv) 15 and (v) 60 days; fresh material frozen for (vi) 15 and (vii) 60 days. After oven drying, samples were analyzed for δ15N, δ13C values, N(%), C(%) and C/N atomic values using continuous flow isotope ratio mass spectrometry. All preservation methods tested, significantly impacted δ13C and δ15N and C/N atomic values. Chemical preservatives caused δ13C enrichment as great as 1.5‰, and δ15N enrichment as great as 0.9‰; the one exception was M. doucasae stored in ethanol for 15 days, which had δ15N depletion up to 1.8‰. Freezing depleted δ13C and δ15N by up to 0.7 and 2.2‰, respectively. C/N atomic values decreased when stored in ethanol, and increased when frozen for 60 days for both cricket species. Our results indicate that all preservation methods tested in this study altered at least one of the tested isotope values when compared to fresh material (controls). We conclude that only freshly processed material provides adequate SIA results for litter-dwelling crickets.
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Affiliation(s)
- Fabiene Maria Jesus
- Programa de Pós-graduação em Ecologia, Departamento de Biologia Geral, Universidade Federal de Viçosa, Viçosa, MG, Brazil
- * E-mail:
| | - Marcelo Ribeiro Pereira
- Universidade Federal do Espírito Santo, Centro de Ciências Agrárias, Departamento de Biologia, Alegre, ES, Brazil
| | - Cassiano Sousa Rosa
- Universidade Federal do Triângulo Mineiro, Campus Iturama, Curso de Ciências Biológicas, Iturama, MG, Brazil
| | - Marcelo Zacharias Moreira
- Laboratório de Ecologia Isotópica, Centro de Energia Nuclear na Agricultura—CENA/USP, Piracicaba, SP, Brazil
| | - Carlos Frankl Sperber
- Programa de Pós-graduação em Ecologia, Departamento de Biologia Geral, Universidade Federal de Viçosa, Viçosa, MG, Brazil
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Wolf N, Newsome SD, Peters J, Fogel ML. Variability in the routing of dietary proteins and lipids to consumer tissues influences tissue-specific isotopic discrimination. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2015; 29:1448-1456. [PMID: 26147485 DOI: 10.1002/rcm.7239] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 04/27/2015] [Accepted: 05/26/2015] [Indexed: 06/04/2023]
Abstract
RATIONALE The eco-physiological mechanisms that govern the incorporation and routing of macronutrients from dietary sources into consumer tissues determine the efficacy of stable isotope analysis (SIA) for studying animal foraging ecology. We document how changes in the relative amounts of dietary proteins and lipids affect the metabolic routing of these macronutrients and the consequent effects on tissue-specific discrimination factors in domestic mice using SIA. We also examine the effects of dietary macromolecular content on a commonly used methodological approach: lipid extraction of potential food sources. METHODS We used carbon ((13) C) and nitrogen ((15) N) isotopes to examine the routing of carbon from dietary proteins and lipids that were used by mice to biosynthesize hair, blood, muscle, and liver. Growing mice were fed one of four diet treatments in which the total dietary content of C4 -based lipids (δ(13) C = -14.5‰) and C(3) -based proteins (δ(13) C = -27‰) varied inversely between 5% and 40%. RESULTS The δ(13) C values of mouse tissues increased by approximately 2-6‰ with increasing dietary lipid content. The difference in δ(13) C values between mouse tissues and bulk diet ranged from 0.1 ± 1.5‰ to 2.3 ± 0.6‰ for all diet treatments. The mean (±SD) difference between the δ(13) C values of mouse tissues and dietary protein varied systematically among tissues and ranged from 3.1 ± 0.1‰ to 4.5 ± 0.6‰ for low fat diets and from 5.4 ± 0.4‰ to 10.5 ± 7.3‰ for high fat diets. CONCLUSIONS Mice used some fraction of their dietary lipid carbon to synthesize tissue proteins, suggesting flexibility in the routing of dietary macromolecules to consumer tissues based on dietary macromolecular availability. Consequently, all constituent dietary macromolecules, not just protein, should be considered when determining the relationship between diets and consumer tissues using SIA. In addition, in cases where animals consume diets with high lipid contents, non lipid-extracted prey samples should be analyzed to estimate diets using SIA.
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Affiliation(s)
- Nathan Wolf
- Fairweather Science LLC, Anchorage, AK, 99515, USA
| | - Seth D Newsome
- University of New Mexico, Department of Biology, Albuquerque, NM, 87131, USA
| | - Jacob Peters
- Harvard University, Organismic and Evolutionary Biology, Cambridge, MA, 02138, USA
| | - Marilyn L Fogel
- University of California Merced, Environmental Sciences, Merced, CA, 95343, USA
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45
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Greer AL, Horton TW, Nelson XJ. Simple ways to calculate stable isotope discrimination factors and convert between tissue types. Methods Ecol Evol 2015. [DOI: 10.1111/2041-210x.12421] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Amanda L. Greer
- School of Biological Sciences University of Canterbury Private Bag 4800 Christchurch 8140 New Zealand
| | - Travis W. Horton
- Department of Geological Sciences University of Canterbury Private Bag 4800 Christchurch 8140 New Zealand
| | - Ximena J. Nelson
- School of Biological Sciences University of Canterbury Private Bag 4800 Christchurch 8140 New Zealand
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Naito YI, Morita A, Natsuhara K, Tadokoro K, Baba J, Odani S, Tomitsuka E, Igai K, Tsutaya T, Yoneda M, Greenhill AR, Horwood PF, Soli KW, Phuanukoonnon S, Siba PM, Umezaki M. Association of protein intakes and variation of diet-scalp hair nitrogen isotopic discrimination factor in Papua New Guinea highlanders. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2015; 158:359-70. [DOI: 10.1002/ajpa.22798] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 06/09/2015] [Accepted: 06/09/2015] [Indexed: 11/10/2022]
Affiliation(s)
- Yuichi I. Naito
- Department of Integrated Biosciences; Graduate School of Frontier Sciences, The University of Tokyo; Kashiwanoha 5-1-5 Kashiwa Chiba 277-8562 Japan
| | - Ayako Morita
- Department of Human Ecology; Graduate School of Medicine, The University of Tokyo; 7-3-1 Hongo Bunkyo Tokyo 113-0033 Japan
- Tokyo Medical and Dental University; Yushima 1-5-45 Bunkyo-ku Tokyo 113-8519 Japan
| | - Kazumi Natsuhara
- The Japanese Red Cross Akita College of Nursing; Nawashirosawa 17-3, Saruta, Kamikitate Akita Akita 010-1493 Japan
| | - Kiyoshi Tadokoro
- Department of Human Ecology; Graduate School of Medicine, The University of Tokyo; 7-3-1 Hongo Bunkyo Tokyo 113-0033 Japan
| | - Jun Baba
- The Research Institute for Languages and Cultures of Asia and Africa, Tokyo University of Foreign Studies; 3-11-1 Asahi-cho Fuchu Tokyo 183-8534 Japan
| | - Shingo Odani
- Faculty of Letters, Chiba University; 1-33 Yayoicho, Inage Chiba 263-8522 Japan
| | - Eriko Tomitsuka
- Department of Human Ecology; Graduate School of Medicine, The University of Tokyo; 7-3-1 Hongo Bunkyo Tokyo 113-0033 Japan
| | - Katsura Igai
- Graduate School of Biomedical Science, Nagasaki University; 1-12-4 Sakamoto Nagasaki 852-8523 Japan
| | - Takumi Tsutaya
- Department of Integrated Biosciences; Graduate School of Frontier Sciences, The University of Tokyo; Kashiwanoha 5-1-5 Kashiwa Chiba 277-8562 Japan
| | - Minoru Yoneda
- Department of Integrated Biosciences; Graduate School of Frontier Sciences, The University of Tokyo; Kashiwanoha 5-1-5 Kashiwa Chiba 277-8562 Japan
- The University Museum, The University of Tokyo; Hongo 7-3-1 Bunkyo Tokyo 113-0033 Japan
| | - Andrew R. Greenhill
- Papua New Guinea Institute of Medical Research, PO Box 60, Goroka, Eastern Highlands Province 441; Papua New Guinea
- Federation University; Gippsland Campus Northways Road, Churchill Victoria 3842 Australia
| | - Paul F. Horwood
- Papua New Guinea Institute of Medical Research, PO Box 60, Goroka, Eastern Highlands Province 441; Papua New Guinea
| | - Kevin W. Soli
- Papua New Guinea Institute of Medical Research, PO Box 60, Goroka, Eastern Highlands Province 441; Papua New Guinea
| | - Suparat Phuanukoonnon
- Papua New Guinea Institute of Medical Research, PO Box 60, Goroka, Eastern Highlands Province 441; Papua New Guinea
| | - Peter M. Siba
- Papua New Guinea Institute of Medical Research, PO Box 60, Goroka, Eastern Highlands Province 441; Papua New Guinea
| | - Masahiro Umezaki
- Department of Human Ecology; Graduate School of Medicine, The University of Tokyo; 7-3-1 Hongo Bunkyo Tokyo 113-0033 Japan
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Robb G, Woodborne S, de Bruin P, Medger K, Bennett N. The influence of food quantity on carbon and nitrogen stable isotope values in southern African spiny mice (Acomys spinosissimus). CAN J ZOOL 2015. [DOI: 10.1139/cjz-2014-0134] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Stable isotope analysis is frequently applied as a tool to examine dietary patterns in animals. However, some of the underlying assumptions associated with using this approach are increasingly being questioned. We carried out a controlled diet experiment on the southern African spiny mouse (Acomys spinosissimus Peters, 1852) to test a number of aspects relating to these assumptions and also examine the hypothesis that stable isotopes, especially δ15N, can be used to provide evidence of nutritional stress. We compared the δ13C and δ15N values of livers and blood from animals that were fed ad libitum with animals undergoing a 10% reduction in food supply. Food-restricted animals showed no significant difference in δ15N; however, δ13C values of both liver and blood were depleted. Restricted animals also had a significantly lower C:N ratio. We examined the role of lipids and found following lipid extraction that both livers and lipids still showed the same separation in carbon values. Tissue–diet discrimination values were also calculated and found to be higher for both Δ13C and Δ15N compared with other mice species. Empirical values for discrimination rates were then compared with values calculated using an alternative method based on employing generic values and were found to be dissimilar, suggesting the use of generic values are not always appropriate. Our results highlight the need for greater understanding of the assumptions associated with using stable isotope analysis to examine diet and we suggest that studying a single species under captive conditions presents an ideal method to begin to test these hypotheses.
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Affiliation(s)
- G.N. Robb
- Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - S. Woodborne
- Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
- iThemba LABS, Private Bag 11, WITS 2050, Gauteng, South Africa
| | - P.R. de Bruin
- Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - K. Medger
- Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - N.C. Bennett
- Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
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48
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Orr TJ, Newsome SD, Wolf BO. Cacti supply limited nutrients to a desert rodent community. Oecologia 2015; 178:1045-62. [PMID: 25842296 DOI: 10.1007/s00442-015-3304-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 03/19/2015] [Indexed: 11/28/2022]
Abstract
In the Sonoran Desert, cacti represent a potentially important source of nutrients and water for consumers. Columnar cacti, in particular, produce a large pulse of flowers and succulent fruit during hot summer months. The importance of cactus stems, flowers and fruit to the small mammal community has not been quantified. We exploited natural variation in the carbon isotope (δ(13)C) values of cacti (CAM) versus C3 plants to quantify the relative use of these resources by a diverse desert small mammal community. We also estimated trophic level by measuring nitrogen isotope (δ(15)N) values. We hypothesized that (H1) granivorous heteromyids (kangaroo rats, pocket mice) would exploit the summer pulse of seeds and pulp; (H2) folivorous and omnivorous cactus mice, wood rats, and ground squirrels would exploit cacti stems year-round and seeds when available; and (H3) kangaroo rats and pocket mice would shift from seeds to insects during hot dry months. We found that heteromyids made minimal use of seeds during the period of heavy seed rain. Of the cricetids, only the folivore Neotoma albigula made continuous but highly variable use of cacti resources (annual mean = 32%, range 0-81%), whereas the omnivore Peromyscus eremicus ignored cacti except during the summer, when it exploited seeds and/or fruit pulp (June-July mean = 39%, range 20-64%). We also found little evidence for a shift to greater consumption of insects by heteromyids during the hot dry months. Overall, use of cactus resources by the small mammal community is very limited and highly variable among species.
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Affiliation(s)
- Teri J Orr
- Departments of Biology and Psychology, University of Massachusetts, Amherst, MA, 01003, USA,
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Pimenta G, Denadai J, Sartori M, Pezzato A, Sartori J, Garcia E, Ishizuka A, Luiggi F, Fasanaro R, Pasquali G, Silva E, Ducatti C. Turnover do carbono em sangue e plasma, nas fases crescimento e postura, de codornas japonesas (Coturnix coturnix japonica). ARQ BRAS MED VET ZOO 2014. [DOI: 10.1590/1678-6634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
O estudo objetivou avaliar o turnover do 13C no sangue e plasma de codornas japonesas utilizando a técnica de isótopos estáveis, para a obtenção do patamar de equilíbrio isotópico que servirá de fundamento para estudos de rastreabilidade. Foram utilizadas 300 aves durante o período experimental de 1-42 e 49-97 dias de idade. Os tratamentos da primeira fase foram constituídos de dietas à base de arroz (C3), contendo ou não farinha de carne e ossos bovinos e um com dieta à base de milho (C4). Nessa primeira fase foi analisado o turnover do sinal isotópico do matrizeiro à base de dietas C4 para dietas à base de C3, como também as diferenças isotópicas das dietas contendo ou não farinha de origem animal. Na segunda fase houve uma substituição de dietas, ou seja, as aves no tratamento C4 da primeira fase passaram a consumir dieta C3, e o tratamento que antes consumia dieta C3 passou para dieta C4. Para determinar a taxa de turnover e o percentual estimado de participação da farinha na composição do material coletado, foi empregado o modelo de diluição isotópica utilizando valores do δ13C. A comparação entre as meias-vidas do sangue e plasma da primeira fase revelou o enriquecimento do δ13C na dieta; já na segunda fase foi possível observar as velocidades de incorporação após a troca das dietas.
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50
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Isotopic Discrimination Factors (Δ13C and Δ15N) between Tissues and Diet of the Broad-Snouted Caiman (Caiman latirostris). J HERPETOL 2014. [DOI: 10.1670/12-274] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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