1
|
Cansse T, Lens L, Sutton GJ, Botha JA, Arnould JPY. Foraging behaviour and habitat use during chick-rearing in the Australian endemic black-faced cormorant (Phalacrocorax fuscescens). Biol Open 2024; 13:bio060336. [PMID: 38752596 PMCID: PMC11128270 DOI: 10.1242/bio.060336] [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: 01/26/2024] [Accepted: 04/18/2024] [Indexed: 05/28/2024] Open
Abstract
Despite its wide distribution, relatively little is known of the foraging ecology and habitat use of the black-faced cormorant (Phalacrocorax fuscescens), an Australian endemic seabird. Such information is urgently required in view of the rapid oceanic warming of south-eastern Australia, the stronghold of the species. The present study used a combination of opportunistically collected regurgitates and GPS/dive behaviour data loggers to investigate diet, foraging behaviour and habitat-use of black-faced cormorants during four chick-rearing periods (2020-2023) on Notch Island, northern Bass Strait. Observed prey species were almost exclusively benthic (95%), which is consistent with the predominantly benthic diving behaviour recorded. Males foraged at deeper depths than females (median depth males: 18 m; median depth females: 8 m), presumably due to a greater physiological diving capacity derived from their larger body size. This difference in dive depths was associated with sexual segregation of foraging locations, with females predominantly frequenting shallower areas closer to the coastline. These findings have strong implications for the management of the species, as impacts of environmental change may disproportionally affect the foraging range of one sex and, thereby, reproductive success.
Collapse
Affiliation(s)
- Thomas Cansse
- School of Life and Environmental Sciences, Deakin University, Burwood 3125, Australia
- Terrestrial Ecology Unit, Ghent University, Ghent 9000, Belgium
| | - Luc Lens
- Terrestrial Ecology Unit, Ghent University, Ghent 9000, Belgium
| | - Grace J. Sutton
- School of Life and Environmental Sciences, Deakin University, Burwood 3125, Australia
| | - Jonathan A. Botha
- School of Life and Environmental Sciences, Deakin University, Burwood 3125, Australia
| | - John P. Y. Arnould
- School of Life and Environmental Sciences, Deakin University, Burwood 3125, Australia
| |
Collapse
|
2
|
Salton M, Raoult V, Jonsen I, Harcourt R. Niche partitioning and individual specialisation in resources and space use of sympatric fur seals at their range margin. Oecologia 2024; 204:815-832. [PMID: 38568471 PMCID: PMC11062968 DOI: 10.1007/s00442-024-05537-8] [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: 03/22/2022] [Accepted: 03/03/2024] [Indexed: 05/02/2024]
Abstract
Ecological theory predicts niche partitioning between high-level predators living in sympatry as a mechanism to minimise the selective pressure of competition. Accordingly, male Australian fur seals Arctocephalus pusillus doriferus and New Zealand fur seals A. forsteri that live in sympatry should exhibit partitioning in their broad niches (in habitat and trophic dimensions) in order to coexist. However, at the northern end of their distributions in Australia, both are recolonising their historic range after a long absence due to over-exploitation, and their small population sizes suggest competition should be weak and may allow overlap in niche space. We found some niche overlap, yet clear partitioning in diet trophic level (δ15N values from vibrissae), spatial niche space (horizontal and vertical telemetry data) and circadian activity patterns (timing of dives) between males of each species, suggesting competition may remain an active driver of niche partitioning amongst individuals even in small, peripheral populations. Consistent with individual specialisation theory, broad niches of populations were associated with high levels of individual specialisation for both species, despite putative low competition. Specialists in isotopic space were not necessarily specialists in spatial niche space, further emphasising their diverse individual strategies for niche partitioning. Males of each species displayed distinct foraging modes, with Australian fur seals primarily benthic and New Zealand fur seals primarily epipelagic, though unexpectedly high individual specialisation for New Zealand fur seals might suggest marginal populations provide exceptions to the pattern generally observed amongst other fur seals.
Collapse
Affiliation(s)
- Marcus Salton
- School of Natural Sciences, Macquarie University, North Ryde, NSW, 2109, Australia.
- Australian Antarctic Division, Department of Climate Change, Energy, the Environment and Water, Kingston, TAS, 7050, Australia.
| | - Vincent Raoult
- School of Natural Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
- School of Environmental and Life Sciences, University of Newcastle, Ourimbah, 2258, Australia
| | - Ian Jonsen
- School of Natural Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
| | - Robert Harcourt
- School of Natural Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
| |
Collapse
|
3
|
Amelot M, Robert M, Mouchet M, Kopp D. Boreal and Lusitanian species display trophic niche variation in temperate waters. Ecol Evol 2023; 13:e10744. [PMID: 38020684 PMCID: PMC10659821 DOI: 10.1002/ece3.10744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 11/02/2023] [Indexed: 12/01/2023] Open
Abstract
Climate change has non-linear impacts on species distributions and abundance that have cascading effects on ecosystem structure and function. Among them are shifts in trophic interactions within communities. Sites found at the interface between two or more biogeographical regions, where species with diverse thermal preferenda are assembled, are areas of strong interest to study the impact of climate change on communities' interactions. This study examined variation in trophic structure in the Celtic Sea, a temperate environment that hosts a mixture of cold-affiliated Boreal species and warm-affiliated Lusitanian species. Using carbon and nitrogen stable isotope ratios, trophic niche area, width, and position were investigated for 10 abundant and commercially important demersal fish species across space and time. In general, the niches of Boreal species appear to be contracting while those of Lusitanian species expand, although there are some fluctuations among species. These results provide evidence that trophic niches can undergo rapid modifications over short time periods (study duration: 2014-2021) and that this process may be conditioned by species thermal preferenda. Boreal species displayed spatial variation in trophic niche width and seem to be facing increased competition with Lusitanian species for food resources. These findings underscore the need to utilize indicators related to species trophic ecology to track the ecosystem alterations induced by climate change. Such indicators could reveal that the vulnerability of temperate ecosystems is currently being underestimated.
Collapse
Affiliation(s)
- Morgane Amelot
- Centre d'Ecologie et des Sciences de la ConservationUMR 7204 MNHN‐CNRS‐ Sorbonne Université, Muséum national d'Histoire naturelle de ParisParisFrance
- UMR DECOD (Ecosystem Dynamics and Sustainability)IFREMER, INRAE, Institut AgroPlouzaneFrance
| | - Marianne Robert
- UMR DECOD (Ecosystem Dynamics and Sustainability)IFREMER, INRAE, Institut AgroPlouzaneFrance
| | - Maud Mouchet
- Centre d'Ecologie et des Sciences de la ConservationUMR 7204 MNHN‐CNRS‐ Sorbonne Université, Muséum national d'Histoire naturelle de ParisParisFrance
| | - Dorothée Kopp
- UMR DECOD (Ecosystem Dynamics and Sustainability)IFREMER, INRAE, Institut AgroPlouzaneFrance
| |
Collapse
|
4
|
Valenzuela-Toro AM, Mehta R, Pyenson ND, Costa DP, Koch PL. Feeding morphology and body size shape resource partitioning in an eared seal community. Biol Lett 2023; 19:20220534. [PMID: 36883314 PMCID: PMC9993223 DOI: 10.1098/rsbl.2022.0534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023] Open
Abstract
Body size and feeding morphology influence how animals partition themselves within communities. We tested the relationships among sex, body size, skull morphology and foraging in sympatric otariids (eared seals) from the eastern North Pacific Ocean, the most diverse otariid community in the world. We recorded skull measurements and stable carbon (δ13C) and nitrogen (δ15N) isotope values (proxies for foraging) from museum specimens in four sympatric species: California sea lions (Zalophus californianus), Steller sea lions (Eumetopias jubatus), northern fur seals (Callorhinus ursinus) and Guadalupe fur seals (Arctocephalus townsendi). Species and sexes had statistical differences in size, skull morphology and foraging significantly affecting the δ13C values. Sea lions had higher δ13C values than fur seals, and males of all species had higher values than females. The δ15N values were correlated with species and feeding morphology; individuals with stronger bite forces had higher δ15N values. We also found a significant community-wide correlation between skull length (indicator of body length), and foraging, with larger individuals having nearshore habitat preferences, and consuming higher trophic level prey than smaller individuals. Still, there was no consistent association between these traits at the intraspecific level, indicating that other factors might account for foraging variability.
Collapse
Affiliation(s)
- Ana M Valenzuela-Toro
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA 95060, USA.,Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA
| | - Rita Mehta
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA 95060, USA
| | - Nicholas D Pyenson
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA 95060, USA.,Department of Paleontology and Geology, Burke Museum of Natural History and Culture, Seattle, WA 98105, USA
| | - Daniel P Costa
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA 95060, USA.,Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Paul L Koch
- Department of Earth and Planetary Sciences, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| |
Collapse
|
5
|
Life History of the Arctic Squid Gonatus fabricii (Cephalopoda: Oegopsida) Reconstructed by Analysis of Individual Ontogenetic Stable Isotopic Trajectories. Animals (Basel) 2022; 12:ani12243548. [PMID: 36552473 PMCID: PMC9774963 DOI: 10.3390/ani12243548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 11/17/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022] Open
Abstract
Cephalopods are important in Arctic marine ecosystems as predators and prey, but knowledge of their life cycles is poor. Consequently, they are under-represented in the Arctic ecosystems assessment models. One important parameter is the change in ecological role (habitat and diet) associated with individual ontogenies. Here, the life history of Gonatus fabricii, the most abundant Arctic cephalopod, is reconstructed by the analysis of individual ontogenetic trajectories of stable isotopes (δ13C and δ15N) in archival hard body structures. This approach allows the prediction of the exact mantle length (ML) and mass when the species changes its ecological role. Our results show that the life history of G. fabricii is divided into four stages, each having a distinct ecology: (1) epipelagic squid (ML < 20 mm), preying mostly on copepods; (2) epi- and occasionally mesopelagic squid (ML 20−50 mm), preying on larger crustaceans, fish, and cephalopods; (3) meso- and bathypelagic squid (ML > 50 mm), preying mainly on fish and cephalopods; and (4) non-feeding bathypelagic gelatinous females (ML > 200 mm). Existing Arctic ecosystem models do not reflect the different ecological roles of G. fabricii correctly, and the novel data provided here are a necessary baseline for Arctic ecosystem modelling and forecasting.
Collapse
|
6
|
Cárdenas-Alayza S, Adkesson MJ, Edwards MR, Hirons AC, Gutiérrez D, Tremblay Y, Franco-Trecu V. Sympatric otariids increase trophic segregation in response to warming ocean conditions in Peruvian Humboldt Current System. PLoS One 2022; 17:e0272348. [PMID: 35951498 PMCID: PMC9371314 DOI: 10.1371/journal.pone.0272348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 07/18/2022] [Indexed: 11/26/2022] Open
Abstract
Determining trophic habits of predator communities is essential to measure interspecific interactions and response to environmental fluctuations. South American fur seals, Arctocephalus australis (SAFS) and sea lions Otaria byronia (SASL), coexist along the coasts of Peru. Recently, ocean warming events (2014–2017) that can decrease and impoverish prey biomass have occurred in the Peruvian Humboldt Current System. In this context, our aim was to assess the effect of warming events on long-term inter- and intra-specific niche segregation. We collected whisker from SAFS (55 females and 21 males) and SASL (14 females and 22 males) in Punta San Juan, Peru. We used δ13C and δ15N values serially archived in otariid whiskers to construct a monthly time series for 2005–2019. From the same period we used sea level anomaly records to determine shifts in the predominant oceanographic conditions using a change point analysis. Ellipse areas (SIBER) estimated niche width of species-sex groups and their overlap. We detected a shift in the environmental conditions marking two distinct periods (P1: January 2005—October 2013; P2: November 2013—December 2019). Reduction in δ15N in all groups during P2 suggests impoverished baseline values with bottom-up effects, a shift towards consuming lower trophic level prey, or both. Reduced overlap between all groups in P2 lends support of a more redundant assemblage during the colder P1 to a more trophically segregated assemblage during warmer P2. SASL females show the largest variation in response to the warming scenario (P2), reducing both ellipse area and δ15N mean values. Plasticity to adapt to changing environments and feeding on a more available food source without fishing pressure can be more advantageous for female SASL, albeit temporary trophic bottom-up effects. This helps explain larger population size of SASL in Peru, in contrast to the smaller and declining SAFS population.
Collapse
Affiliation(s)
- Susana Cárdenas-Alayza
- Centro para la Sostenibilidad Ambiental, Universidad Peruana Cayetano Heredia, Lima, Peru
- Laboratorio de Ciencias del Mar, Universidad Peruana Cayetano Heredia, Lima, Peru
- UMR 248 MARBEC: IRD–Univ. Montpellier–CNRS–Ifremer, Sète cedex, France
- * E-mail:
| | - Michael J. Adkesson
- Chicago Zoological Society, Brookfield Zoo, Brookfield, Illinois, United States of America
| | - Mickie R. Edwards
- Halmos College of Arts and Sciences, Nova Southeastern University, Dania Beach, Florida, United States of America
| | - Amy C. Hirons
- Halmos College of Arts and Sciences, Nova Southeastern University, Dania Beach, Florida, United States of America
| | - Dimitri Gutiérrez
- Laboratorio de Ciencias del Mar, Universidad Peruana Cayetano Heredia, Lima, Peru
- Programa Maestría en Ciencias del Mar, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Yann Tremblay
- UMR 248 MARBEC: IRD–Univ. Montpellier–CNRS–Ifremer, Sète cedex, France
| | - Valentina Franco-Trecu
- Departamento de Ecología y Evolución, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| |
Collapse
|
7
|
Ogilvy C, Constantine R, Bury SJ, Carroll EL. Diet variation in a critically endangered marine predator revealed with stable isotope analysis. ROYAL SOCIETY OPEN SCIENCE 2022; 9:220470. [PMID: 35991335 PMCID: PMC9382206 DOI: 10.1098/rsos.220470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 07/20/2022] [Indexed: 06/15/2023]
Abstract
Understanding the foraging ecology of animals gives insights into their trophic relationships and habitat use. We used stable isotope analysis to understand the foraging ecology of a critically endangered marine predator, the Māui dolphin. We analysed carbon and nitrogen isotope ratios of skin samples (n = 101) collected from 1993 to 2021 to investigate temporal changes in diet and niche space. Genetic monitoring associated each sample with a DNA profile which allowed us to assess individual and population level changes in diet. Potential prey and trophic level indicator samples were also collected (n = 166; 15 species) and incorporated in Bayesian mixing models to estimate importance of prey types to Māui dolphin diet. We found isotopic niche space had decreased over time, particularly since the 2008 implementation of a Marine Mammal Sanctuary. We observed a decreasing trend in ∂13C and ∂15N values, but this was not linear and several fluctuations in isotope values occurred over time. The largest variation in isotope values occurred during an El Niño event, suggesting that prey is influenced by climate-driven oceanographic variables. Mixing models indicated relative importance of prey remained constant since 2008. The isotopic variability observed here is not consistent with individual specialization, rather it occurs at the population level.
Collapse
Affiliation(s)
- Courtney Ogilvy
- School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand
| | - Rochelle Constantine
- School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand
- Institute of Marine Science, University of Auckland, Auckland 1010, New Zealand
| | - Sarah J. Bury
- National Institute of Water and Atmospheric Research, Greta Point, Wellington 6021, New Zealand
| | - Emma L. Carroll
- School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand
| |
Collapse
|
8
|
Seguel M, Molina-Burgos BE, Perez-Venegas DJ, Chiang G, Harrod C, DeRango E, Paves H. Shifts in maternal foraging strategies during pregnancy promote offspring health and survival in a marine top predator. Oecologia 2022; 199:343-354. [PMID: 35678930 DOI: 10.1007/s00442-022-05200-0] [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: 09/21/2021] [Accepted: 05/21/2022] [Indexed: 11/26/2022]
Abstract
The success of maternal foraging strategies during the rearing period can greatly impact the physiology and survival of dependent offspring. Surprisingly though, little is known on the fitness consequences of foraging strategies during the foetal period. In this study, we characterized variation in maternal foraging strategy throughout pregnancy in a marine top predator (South American fur seal, Arctocephalus australis), and asked if these shifts predicted neonatal health and postnatal survival. We found that during early pregnancy all pregnant females belonged to a single, homogenized foraging niche without evident clusters. Intriguingly though, during late pregnancy, individual fur seal mothers diverged into two distinct foraging niches characterized by a benthic-nearshore and a pelagic-offshore strategy. Females that shifted towards the benthic-nearshore strategy gave birth to pups with greater body mass, higher plasmatic levels of glucose and lower levels of blood urea nitrogen. The pups born to these benthic females were eight times more likely to survive compared to females using the pelagic-offshore foraging strategy during late pregnancy. These survival effects were mediated primarily by the impact of foraging strategies on neonatal glucose independent of protein metabolic profile and body mass. Benthic-nearshore foraging strategies during late pregnancy potentially allow for the greater maternal transfer of glucose to the foetus, leading to higher chances of neonatal survival. These results call for a deeper understanding of the balance between resource acquisition and allocation provided by distinct foraging polymorphisms during critical life-history periods, and how this trade-off may be adaptive under certain environmental conditions.
Collapse
Affiliation(s)
- Mauricio Seguel
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, 419 Gordon St, Guelph, ON, N1G2W1, Canada.
| | - Blanca E Molina-Burgos
- Facultad de Medicina Veterinaria y Agronomía, Universidad de las Americas, Manuel Montt 948, 7500000, Santiago, Chile
- Centro de Investigación Para La Sustentabilidad, Facultad de Ciencias de La Vida, Universidad Andres Bello, 8370251, Santiago, Chile
| | - Diego J Perez-Venegas
- Centro de Investigación y Gestión de Recursos Naturales (CIGREN), Instituto de Biología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Gustavo Chiang
- Departamento de Ecología y Biodiversidad and Centro de Investigación Para La Sustentabilidad (CIS), Facultad de Ciencias de La Vida, Universidad Andrés Bello, 8370251, Santiago, Chile
| | - Chris Harrod
- University of Antofagasta Stable Isotope Facility, University of Antofagasta, Antofagasta, Chile
- Instituto de Ciencias Naturales Alexander Von Humboldt, Universidad de Antofagasta, Antofagasta, Chile
- Nucleo Milenio INVASAL, Concepción, Chile
| | - Eugene DeRango
- Department of Animal Behaviour, Bielefeld University, Bielefeld, Germany
| | - Hector Paves
- Departamento de Ciencias Básicas, Facultad de Ciencias, Universidad Santo Tomas, Osorno, Chile
| |
Collapse
|