1
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Ozaki S, Movalli P, Cincinelli A, Alygizakis N, Badry A, Carter H, Chaplow JS, Claßen D, Dekker RWRJ, Dodd B, Duke G, Koschorreck J, Pereira MG, Potter E, Sleep D, Slobodnik J, Thomaidis NS, Treu G, Walker L. Significant Turning Point: Common Buzzard ( Buteo buteo) Exposure to Second-Generation Anticoagulant Rodenticides in the United Kingdom. Environ Sci Technol 2024; 58:6093-6104. [PMID: 38545700 PMCID: PMC11008253 DOI: 10.1021/acs.est.3c09052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 03/12/2024] [Accepted: 03/13/2024] [Indexed: 04/10/2024]
Abstract
Second-generation anticoagulant rodenticides (SGARs) are widely used to control rodent populations, resulting in the serious secondary exposure of predators to these contaminants. In the United Kingdom (UK), professional use and purchase of SGARs were revised in the 2010s. Certain highly toxic SGARs have been authorized since then to be used outdoors around buildings as resistance-breaking chemicals under risk mitigation procedures. However, it is still uncertain whether and how these regulatory changes have influenced the secondary exposure of birds of prey to SGARs. Based on biomonitoring of the UK Common Buzzard (Buteo buteo) collected from 2001 to 2019, we assessed the temporal trend of exposure to SGARs and statistically determined potential turning points. The magnitude of difenacoum decreased over time with a seasonal fluctuation, while the magnitude and prevalence of more toxic brodifacoum, authorized to be used outdoors around buildings after the regulatory changes, increased. The summer of 2016 was statistically identified as a turning point for exposure to brodifacoum and summed SGARs that increased after this point. This time point coincided with the aforementioned regulatory changes. Our findings suggest a possible shift in SGAR use to brodifacoum from difenacoum over the decades, which may pose higher risks of impacts on wildlife.
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Affiliation(s)
- Shinji Ozaki
- UK
Centre for Ecology and Hydrology, Lancaster
Environment Centre, Library
Avenue, Bailrigg, Lancaster LA1 4AP, United
Kingdom
| | - Paola Movalli
- Naturalis
Biodiversity Center, Darwinweg 2, 2333 CR Leiden, Netherlands
| | - Alessandra Cincinelli
- Department
of Chemistry “Ugo Schiff”, University of Florence, Via della Lastruccia 3, 50019 Florence, Italy
| | - Nikiforos Alygizakis
- Environmental
Institute, Okružná
784/42, 97241 Koš, Slovak Republic
- Department
of Chemistry, National and Kapodistrian
University of Athens, Panepistimiopolis Zographou, 15771 Athens, Greece
| | - Alexander Badry
- German Environment
Agency (Umweltbundesamt), Wörlitzer Platz 1, 06813 Dessau-Roßlau, Germany
| | - Heather Carter
- UK
Centre for Ecology and Hydrology, Lancaster
Environment Centre, Library
Avenue, Bailrigg, Lancaster LA1 4AP, United
Kingdom
| | - Jacqueline S. Chaplow
- UK
Centre for Ecology and Hydrology, Lancaster
Environment Centre, Library
Avenue, Bailrigg, Lancaster LA1 4AP, United
Kingdom
| | - Daniela Claßen
- German Environment
Agency (Umweltbundesamt), Wörlitzer Platz 1, 06813 Dessau-Roßlau, Germany
| | | | - Beverley Dodd
- UK
Centre for Ecology and Hydrology, Lancaster
Environment Centre, Library
Avenue, Bailrigg, Lancaster LA1 4AP, United
Kingdom
| | - Guy Duke
- UK
Centre for Ecology and Hydrology, MacLean Bldg, Benson Ln, Crowmarsh Gifford, Wallingford OX10 8BB, United Kingdom
| | - Jan Koschorreck
- German Environment
Agency (Umweltbundesamt), Wörlitzer Platz 1, 06813 Dessau-Roßlau, Germany
| | - M. Glória Pereira
- UK
Centre for Ecology and Hydrology, Lancaster
Environment Centre, Library
Avenue, Bailrigg, Lancaster LA1 4AP, United
Kingdom
| | - Elaine Potter
- UK
Centre for Ecology and Hydrology, Lancaster
Environment Centre, Library
Avenue, Bailrigg, Lancaster LA1 4AP, United
Kingdom
| | - Darren Sleep
- UK
Centre for Ecology and Hydrology, Lancaster
Environment Centre, Library
Avenue, Bailrigg, Lancaster LA1 4AP, United
Kingdom
| | | | - Nikolaos S. Thomaidis
- Department
of Chemistry, National and Kapodistrian
University of Athens, Panepistimiopolis Zographou, 15771 Athens, Greece
| | - Gabriele Treu
- German Environment
Agency (Umweltbundesamt), Wörlitzer Platz 1, 06813 Dessau-Roßlau, Germany
| | - Lee Walker
- UK
Centre for Ecology and Hydrology, Lancaster
Environment Centre, Library
Avenue, Bailrigg, Lancaster LA1 4AP, United
Kingdom
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2
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Tomita KM, Hiura T. Brown bear digging decreases tree growth: Implication for ecological role of top predators in anthropogenic landscapes. Ecology 2024; 105:e4266. [PMID: 38425026 DOI: 10.1002/ecy.4266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 11/10/2023] [Accepted: 01/19/2024] [Indexed: 03/02/2024]
Abstract
Large carnivores have recently increased in number and recolonized in human-dominated landscapes; however, their ecological roles in these landscapes have not been well studied. In the Shiretoko World Heritage (SWH) site, brown bears have recolonized a previously abandoned mosaic landscape of natural forests and conifer plantations after land abandonment. We previously reported that the bears had recently begun to dig for cicada nymphs in association with the creation of larch plantations. As a result, this digging activity decreased soil nutrients. To deepen the understanding of the novel ecological role of brown bears within human-modified landscapes, we examined the impacts of brown bear digging on the growth of larch trees. We found that brown bear digging decreased fine root biomass of larch, soil water, and nitrogen availability. Brown bear digging negatively affected needle nitrogen content, but not carbon isotope ratios, a water stress index of trees. Tree ring data suggest that digging negatively affected the radial growth of larches. The results imply that digging decreases tree growth due to limited soil nitrogen uptake. Our findings indicate that the ecological roles of large carnivores may differ between natural and anthropogenic landscapes.
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Affiliation(s)
- Kanji M Tomita
- Faculty of Agriculture and Marine Science Kochi University, Nankoku, Japan
| | - Tsutom Hiura
- Department of Ecosystem Studies, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, Japan
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3
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Koju NP, Gosai KR, Bashyal B, Byanju R, Shrestha A, Buzzard P, Beisch WB, Khanal L. Seasonal Prey Abundance and Food Plasticity of the Vulnerable Snow Leopard ( Panthera uncia) in the Lapchi Valley, Nepal Himalayas. Animals (Basel) 2023; 13:3182. [PMID: 37893906 PMCID: PMC10603713 DOI: 10.3390/ani13203182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 10/09/2023] [Accepted: 10/10/2023] [Indexed: 10/29/2023] Open
Abstract
Conservation strategies for apex predators, like the snow leopard (Panthera uncia), depend on a robust understanding of their dietary preferences, prey abundance, and adaptability to changing ecological conditions. To address these critical conservation concerns, this study presents a comprehensive evidence on prey availability and preferences for snow leopards in the Lapchi Valley in the Nepal Himalayas from November 2021 to March 2023. Field data were collected through the installation of twenty-six camera traps at 16 strategically chosen locations, resulting in the recording of 1228 events of 19 mammalian species, including domesticated livestock. Simultaneously, the collection of twenty snow leopard scat samples over 3800 m above sea level allowed for a detailed dietary analysis. Photo capture rate index and biomass composition analysis were carried out and seasonal prey availability and consumption were statistically analyzed. A total of 16 potential prey species for the snow leopard were documented during the study period. Himalayan musk deer (Moschus leucogaster) was the most abundant prey species, but infrequent in the diet suggesting that are not the best bet prey for the snow leopards. Snow leopards were found to exhibit a diverse diet, consuming eleven prey species, with blue sheep (Pseudois nayaur) being their most consumed wild prey and horses as their preferred livestock. The Pianka's index of dietary niche overlap between the summer and winter seasons were 0.576, suggesting a pronounced seasonal variation in food preference corroborating with the prey availability. The scarcity of larger preys in winter is compensated by small and meso-mammals in the diet, highlighting the snow leopard's capacity for dietary plasticity in response to the variation in resource availability. This research suggests for the utilization of genetic tools to further explore snow leopard diet composition. Additionally, understanding transboundary movements and conducting population assessments will be imperative for the formulation of effective conservation strategies.
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Affiliation(s)
- Narayan Prasad Koju
- Center for Post Graduate Studies, Nepal Engineering College, Pokhara University, Lekhnath 44800, Nepal;
- Department of Psychology, University of Washington, Guthrie Hall (GTH), Seattle, WA 98105, USA
| | - Kamal Raj Gosai
- Trichandra Multiple Campus, Tribhuvan University, Kathmandu 44613, Nepal;
| | - Bijay Bashyal
- Central Department of Environmental Science, Tribhuvan University, Kathmandu 44613, Nepal;
| | - Reena Byanju
- Patan Multiple Campus, Tribhuvan University, Kathmandu 44613, Nepal;
| | - Arati Shrestha
- Department of Environment, Ministry of Forest and Environment, Kathmandu 44600, Nepal;
| | - Paul Buzzard
- China Exploration and Research Society, Hong Kong, China; (P.B.); (W.B.B.)
- Washtenaw County Conservation District, Ann Arbor, MI 48103, USA
| | | | - Laxman Khanal
- Central Department of Zoology, Institute of Science and Technology, Tribhuvan University, Kathmandu 44613, Nepal
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4
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Jordaan RK, Oosthuizen WC, Reisinger RR, de Bruyn PJN. The effect of prey abundance and fisheries on the survival, reproduction, and social structure of killer whales ( Orcinus orca) at subantarctic Marion Island. Ecol Evol 2023; 13:e10144. [PMID: 37284666 PMCID: PMC10239896 DOI: 10.1002/ece3.10144] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 05/08/2023] [Accepted: 05/15/2023] [Indexed: 06/08/2023] Open
Abstract
Most marine apex predators are keystone species that fundamentally influence their ecosystems through cascading top-down processes. Reductions in worldwide predator abundances, attributed to environmental- and anthropogenic-induced changes to prey availability and negative interactions with fisheries, can have far-reaching ecosystem impacts. We tested whether the survival of killer whales (Orcinus orca) observed at Marion Island in the Southern Indian Ocean correlated with social structure and prey variables (direct measures of prey abundance, Patagonian toothfish fishery effort, and environmental proxies) using multistate models of capture-recapture data spanning 12 years (2006-2018). We also tested the effect of these same variables on killer whale social structure and reproduction measured over the same period. Indices of social structure had the strongest correlation with survival, with higher sociality associated with increased survival probability. Survival was also positively correlated with Patagonian toothfish fishing effort during the previous year, suggesting that fishery-linked resource availability is an important determinant of survival. No correlation between survival and environmental proxies of prey abundance was found. At-island prey availability influenced the social structure of Marion Island killer whales, but none of the variables explained variability in reproduction. Future increases in legal fishing activity may benefit this population of killer whales through the artificial provisioning of resources they provide.
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Affiliation(s)
- Rowan K. Jordaan
- Mammal Research Institute, Department of Zoology and EntomologyUniversity of PretoriaPretoriaSouth Africa
| | - W. Chris Oosthuizen
- Centre for Statistics in Ecology, the Environment (SEEC)University of Cape TownCape TownSouth Africa
| | - Ryan R. Reisinger
- Ocean and Earth ScienceUniversity of Southampton, National Oceanography Centre SouthamptonSouthamptonUK
| | - P. J. Nico de Bruyn
- Mammal Research Institute, Department of Zoology and EntomologyUniversity of PretoriaPretoriaSouth Africa
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5
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Leach CB, Weitzman BP, Bodkin JL, Esler D, Esslinger GG, Kloecker KA, Monson DH, Womble JN, Hooten MB. Revealing the extent of sea otter impacts on bivalve prey through multi-trophic monitoring and mechanistic models. J Anim Ecol 2023. [PMID: 37081640 DOI: 10.1111/1365-2656.13929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 03/22/2023] [Indexed: 04/22/2023]
Abstract
Sea otters are apex predators that can exert considerable influence over the nearshore communities they occupy. Since facing near extinction in the early 1900s, sea otters are making a remarkable recovery in Southeast Alaska, particularly in Glacier Bay, the largest protected tidewater glacier fjord in the world. The expansion of sea otters across Glacier Bay offers both a challenge to monitoring and stewardship and an unprecedented opportunity to study the top-down effect of a novel apex predator across a diverse and productive ecosystem. Our goal was to integrate monitoring data across trophic levels, space, and time to quantify and map the predator-prey interaction between sea otters and butter clams Saxidomus gigantea, one of the dominant large bivalves in Glacier Bay and a favoured prey of sea otters. We developed a spatially-referenced mechanistic differential equation model of butter clam dynamics that combined both environmental drivers of local population growth and estimates of otter abundance from aerial survey data. We embedded this model in a Bayesian statistical framework and fit it to clam survey data from 43 intertidal and subtidal sites across Glacier Bay. Prior to substantial sea otter expansion, we found that butter clam density was structured by an environmental gradient driven by distance from glacier (represented by latitude) and a quadratic effect of current speed. Estimates of sea otter attack rate revealed spatial heterogeneity in sea otter impacts and a negative relationship with local shoreline complexity. Sea otter exploitation of productive butter clam habitat substantially reduced the abundance and altered the distribution of butter clams across Glacier Bay, with potential cascading consequences for nearshore community structure and function. Spatial variation in estimated sea otter predation processes further suggests that community context and local environmental conditions mediate the top-down influence of sea otters on a given prey. Overall, our framework provides high-resolution insights about the interaction among components of this food web and could be applied to a variety of other systems involving invasive species, epidemiology or migration.
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Affiliation(s)
- Clinton B Leach
- Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, Colorado, USA
| | - Benjamin P Weitzman
- U.S. Fish and Wildlife Service, Marine Mammals Management, Anchorage, Alaska, USA
| | - James L Bodkin
- U.S. Geological Survey, Alaska Science Center, Anchorage, Alaska, USA
| | - Daniel Esler
- U.S. Geological Survey, Alaska Science Center, Anchorage, Alaska, USA
| | | | | | - Daniel H Monson
- U.S. Geological Survey, Alaska Science Center, Anchorage, Alaska, USA
| | - Jamie N Womble
- Southeast Alaska Inventory and Monitoring Network, National Park Service, Juneau, Alaska, USA
- Glacier Bay Field Station, National Park Service, Juneau, Alaska, USA
| | - Mevin B Hooten
- Department of Statistics and Data Sciences, The University of Texas at Austin, Austin, Texas, USA
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6
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Lazarus M, Sekovanić A, Reljić S, Kusak J, Ferenčaković M, Sindičić M, Gomerčić T, Huber Đ. Lead and Other Trace Element Levels in Brains of Croatian Large Terrestrial Carnivores: Influence of Biological and Ecological Factors. Toxics 2022; 11:4. [PMID: 36668730 PMCID: PMC9865836 DOI: 10.3390/toxics11010004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 12/14/2022] [Accepted: 12/19/2022] [Indexed: 06/17/2023]
Abstract
Trace element pollution can adversely affect the brains of individuals and thus impact the entire population of apex predators, such as large European carnivores. We assessed exposure to prominent neurotoxicants As, Cd, Hg and Pb by measuring their brain stem levels in brown bears (n = 114), grey wolves (n = 8), Eurasian lynx (n = 3), and golden jackals (n = 2) sampled in 2015-2022 in Croatia. The highest of the non-essential elements was the Pb level in the bears' brains (median, Q1-Q3; 11.1, 7.13-24.1 μg/kg wet mass), with 4% of animals, all subadults, exceeding the established normal bovine levels (100 μg/kg wet mass). Species-specific differences were noted for Ca, Cd, Cu, Fe, Pb and Se brain levels. Female brown bears had higher As brain levels than males. Cubs and yearlings had lower brain Cd, but higher Zn, while subadults had higher Cu than adult bears. Hepatic As, Cd, Cu and Hg levels were shown to be a moderate proxy for estimating brain levels in bears (rS = 0.30-0.69). Multiple associations of As, Cd, Hg and Pb with essential elements pointed to a possible interaction and disturbance of brain Ca, Cu, Fe, Se and Zn homeostasis. Non-essential element levels in the brains of four studied species were lower than reported earlier for terrestrial meso-carnivores and humans. The age and sex of animals were highlighted as essential factors in interpreting brain element levels in ecotoxicological studies of large carnivores.
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Affiliation(s)
- Maja Lazarus
- Institute for Medical Research and Occupational Health, 10000 Zagreb, Croatia
| | - Ankica Sekovanić
- Faculty of Veterinary Medicine, University of Zagreb, 10000 Zagreb, Croatia
| | - Slaven Reljić
- Faculty of Veterinary Medicine, University of Zagreb, 10000 Zagreb, Croatia
| | - Josip Kusak
- Faculty of Veterinary Medicine, University of Zagreb, 10000 Zagreb, Croatia
| | | | - Magda Sindičić
- Faculty of Veterinary Medicine, University of Zagreb, 10000 Zagreb, Croatia
| | - Tomislav Gomerčić
- Faculty of Veterinary Medicine, University of Zagreb, 10000 Zagreb, Croatia
| | - Đuro Huber
- Faculty of Veterinary Medicine, University of Zagreb, 10000 Zagreb, Croatia
- Institute of Nature Conservation, Polish Academy of Sciences, 31-343 Krakow, Poland
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7
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Campbell MA, Udyawer V, Jardine TD, Fukuda Y, Kopf RK, Bunn SE, Campbell HA. Dietary shifts may underpin the recovery of a large carnivore population. Biol Lett 2022; 18:20210676. [PMID: 35472283 PMCID: PMC9042529 DOI: 10.1098/rsbl.2021.0676] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Supporting the recovery of large carnivores is a popular yet challenging endeavour. Estuarine crocodiles in Australia are a large carnivore conservation success story, with the population having extensively recovered from past heavy exploitation. Here, we explored if dietary changes had accompanied this large population recovery by comparing the isotopes δ13C and δ15N in bones of crocodiles sampled 40 to 55 years ago (small population) with bones from contemporary individuals (large population). We found that δ13C and δ15N values were significantly lower in contemporary crocodiles than in the historical cohort, inferring a shift in prey preference away from marine and into terrestrial food webs. We propose that an increase in intraspecific competition within the recovering crocodile population, alongside an increased abundance of feral ungulates occupying the floodplains, may have resulted in the crocodile population shifting to feed predominantly upon terrestrial food sources. The number of feral pigs consumed to sustain and grow crocodile biomass may help suppress pig population growth and increase the flow of terrestrially derived nutrients into aquatic ecosystems. The study highlights the significance of prey availability in contributing to large carnivore population recovery.
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Affiliation(s)
- Mariana A Campbell
- Research Institute for the Environment and Livelihoods, College of Engineering, IT and Environment, Charles Darwin University, Darwin, NT, Australia
| | - Vinay Udyawer
- Australian Institute of Marine Science, Darwin, NT, Australia
| | - Timothy D Jardine
- School of Environment and Sustainability, University of Saskatchewan, Saskatoon, SK, Canada.,Australian Rivers Institute, Griffith University, Nathan, QLD, Australia
| | - Yusuke Fukuda
- Department of Environment, Parks and Water Security, Darwin, NT, Australia
| | - R Keller Kopf
- Research Institute for the Environment and Livelihoods, College of Engineering, IT and Environment, Charles Darwin University, Darwin, NT, Australia
| | - Stuart E Bunn
- Australian Rivers Institute, Griffith University, Nathan, QLD, Australia
| | - Hamish A Campbell
- Research Institute for the Environment and Livelihoods, College of Engineering, IT and Environment, Charles Darwin University, Darwin, NT, Australia
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8
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Hammerschlag N, Fallows C, Meÿer M, Seakamela SM, Orndorff S, Kirkman S, Kotze D, Creel S. Loss of an apex predator in the wild induces physiological and behavioural changes in prey. Biol Lett 2022; 18:20210476. [PMID: 35078332 PMCID: PMC8790382 DOI: 10.1098/rsbl.2021.0476] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 12/20/2021] [Indexed: 01/28/2023] Open
Abstract
Predators can impact prey via predation or risk effects, which can initiate trophic cascades. Given widespread population declines of apex predators, understanding and predicting the associated ecological consequences is a priority. When predation risk is relatively unpredictable or uncontrollable by prey, the loss of predators is hypothesized to release prey from stress; however, there are few tests of this hypothesis in the wild. A well-studied predator-prey system between white sharks (Carcharodon carcharias) and Cape fur seals (Arctocephalus pusillus pusillus) in False Bay, South Africa, has previously demonstrated elevated faecal glucocorticoid metabolite concentrations (fGCMs) in seals exposed to high levels of predation risk from white sharks. A recent decline and disappearance of white sharks from the system has coincided with a pronounced decrease in seal fGCM concentrations. Seals have concurrently been rafting further from shore and over deeper water, a behaviour that would have previously rendered them vulnerable to attack. These results show rapid physiological and behavioural responses by seals to release from predation stress. To our knowledge, this represents the first demonstration in the wild of physiological changes in prey from predator decline, and such responses are likely to increase given the scale and pace of apex predator declines globally.
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Affiliation(s)
- Neil Hammerschlag
- Department of Environmental Science and Policy, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149, USA
| | - Chris Fallows
- Apex Shark Expeditions, Shop 3 Quayside Center, Simonstown, Cape Town 7975, South Africa
| | - Michael Meÿer
- Department of Forestry, Fisheries and the Environment, Oceans and Coasts Branch, 2 East Pier Road, Waterfront, Cape Town 8000, South Africa
| | - Simon Mduduzi Seakamela
- Department of Forestry, Fisheries and the Environment, Oceans and Coasts Branch, 2 East Pier Road, Waterfront, Cape Town 8000, South Africa
| | - Samantha Orndorff
- Department of Environmental Science and Policy, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149, USA
| | - Steve Kirkman
- Department of Forestry, Fisheries and the Environment, Oceans and Coasts Branch, 2 East Pier Road, Waterfront, Cape Town 8000, South Africa
- Marine Apex Predator Research Unit (MAPRU), Department of Zoology and Institute for Coastal and Marine Research, Nelson Mandela University, Port Elizabeth 6031, South Africa
| | - Deon Kotze
- Department of Forestry, Fisheries and the Environment, Oceans and Coasts Branch, 2 East Pier Road, Waterfront, Cape Town 8000, South Africa
| | - Scott Creel
- Department of Ecology, Montana State University, Bozeman, MT 59717, USA
- Institutionen för Vilt, Fisk och Miljö, Sveriges lantbruksuniversitet, 90183 Umeå, Sweden
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9
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de Azevedo FCC, Pasa JB, Arrais RC, Massara RL, Widmer CE. Density and habitat use of one of the last jaguar populations of the Brazilian Atlantic Forest: Is there still hope? Ecol Evol 2022; 12:e8487. [PMID: 35136550 PMCID: PMC8809435 DOI: 10.1002/ece3.8487] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 11/30/2021] [Accepted: 12/02/2021] [Indexed: 11/26/2022] Open
Abstract
The jaguar (Panthera onca) plays an important role in maintaining biodiversity and ecological processes. We evaluated the status of a jaguar population in one of the last stronghold habitats for its conservation in the Atlantic Forest, the Rio Doce State Park (RDSP). We used a random survey design from 2016/17 to estimate jaguar abundance and density as well as its occupancy and detection probabilities in the entire Park's area. To monitor for temporal fluctuations in density and abundance, we used a systematic survey design in the southern portion of the Park where jaguars were more recorded when using the random approach. We then conducted two surveys in 2017/18 and 2020. Our 2016/17 random survey revealed that jaguar density (0.11 ± SE 0.28 individuals/100 km2) was the lowest obtained for the species across the Atlantic Forest. We noticed that jaguar density increased three times from 2017/18 (0.55 ± SE 0.45 individuals/100 km2) to 2020 (1.61 ± SE 0.6 individuals/100 km2). Jaguar occupancy and detection probability were 0.40 and 0.08, respectively. The low jaguar occupancy probability was positively associated with smaller distances from lakes and records of potential prey. The detection probability was positively associated with prey detection, the rainy season, and smaller distances from lakes. Our work contributes to a growing awareness of the potential conservation value of a protected area in a human-dominated landscape as one of the last strongholds for jaguars across the Atlantic Forest.
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Affiliation(s)
| | - Juliana Benck Pasa
- Programa de Pós‐Graduação em EcologiaUniversidade Federal de São João del ReiSão João del ReiBrasil
| | - Ricardo Corassa Arrais
- Programa de Pós‐graduação em Ecologia, Conservação e Manejo da Vida SilvestreDepartamento de Genética, Ecologia e EvoluçãoInstituto de Ciências BiológicasUniversidade Federal de Minas GeraisBelo HorizonteBrasil
| | - Rodrigo Lima Massara
- Programa de Pós‐graduação em Ecologia, Conservação e Manejo da Vida SilvestreDepartamento de Genética, Ecologia e EvoluçãoInstituto de Ciências BiológicasUniversidade Federal de Minas GeraisBelo HorizonteBrasil
| | - Cynthia Elisa Widmer
- Departamento de Ciências NaturaisUniversidade Federal de São João del ReiSão João del ReiBrasil
- Projeto Carnívoros do Rio Doce – PCRDParque Estadual do Rio DoceMarliériaBrasil
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10
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Zanón Martínez JI, Seoane J, Kelly MJ, Sarasola JH, Travaini A. Assessing carnivore spatial co-occurrence and temporal overlap in the face of human interference in a semiarid forest. Ecol Appl 2022; 32:e02482. [PMID: 34674337 DOI: 10.1002/eap.2482] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 03/27/2021] [Accepted: 05/18/2021] [Indexed: 06/13/2023]
Abstract
Apex predators drive top-down effects in ecosystems and the loss of such species can trigger mesopredator release. This ecological process has been well documented in human-modified small areas, but for management and conservation of ecological communities, it is important to know which human factors affect apex predator occurrence and which mediate mesopredators release at large scales. We hypothesized that mesopredators would avoid spatial and temporal overlap with the apex predator, the puma; but that human perturbations (i.e., cattle raising and trophy hunting) would dampen top-down effects and mediate habitat use. We installed 16 camera traps in each of 45, 10 × 10 km grid cells in the Caldén forest region of central Argentina resulting in 706 total stations covering 61,611 km2 . We used single-season occupancy and two-species co-occurrence models and calculated the species interaction factor (SIF) to explore the contributions of habitat, biotic, and anthropic variables in explaining co-occurrence between carnivore pairs. We also used kernel density estimation techniques to analyze temporal overlap in activity patterns of the carnivore guild. We found that puma habitat use increased with abundance of large prey and with proximity to protected areas. Geoffroy's cats and skunks spatially avoided pumas and this effect was strong and mediated by distance to protected areas and game reserves, but pumas did not influence pampas fox and pampas cat space use. At medium and low levels of puma occupancy, we found evidence of spatial avoidance between three pairs of mesocarnivores. All predators were mostly nocturnal and crepuscular across seasons and mesopredators showed little consistent evidence of changing activity patterns with varying levels of puma occupancy or human interference. We found potential for mesopredator release at large scale, especially on the spatial niche axis. Our results suggest that a combination of interacting factors, in conjunction with habitat features and intervening human activities, may make mesopredator release unlikely or difficult to discern at broad scales. Overall, we believe that promoting the creation of new protected areas linked by small forest patches would likely lead to increased predator and prey abundances, as well as the interactions among carnivores inside and outside of protected areas.
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Affiliation(s)
- Juan I Zanón Martínez
- Instituto de Ciencias de la Tierra y Ambientales de La Pampa, Consejo Nacional de Investigaciones Científicas y Técnicas, Avenida Uruguay 151, 6300, Santa Rosa, La Pampa, Argentina
- Centro para el Estudio y Conservación de las Aves Rapaces en Argentina, Universidad Nacional de La Pampa, Avenida Uruguay 151, 6300, Santa Rosa, La Pampa, Argentina
| | - Javier Seoane
- Terrestrial Ecology Group-TEG, Department of Ecology, Universidad Autónoma de Madrid, C/Darwin, 2, 28049, Madrid, Spain
- Centro de Investigación en Biodiversidad y Cambio Global (CIBC-UAM), Universidad Autónoma de Madrid, Madrid, Spain
| | - Marcella J Kelly
- Department of Fish and Wildlife Conservation, Virginia Tech, 146 Cheatham Hall, Blacksburg, Virginia, 24061-0321, USA
| | - José Hernán Sarasola
- Instituto de Ciencias de la Tierra y Ambientales de La Pampa, Consejo Nacional de Investigaciones Científicas y Técnicas, Avenida Uruguay 151, 6300, Santa Rosa, La Pampa, Argentina
- Centro para el Estudio y Conservación de las Aves Rapaces en Argentina, Universidad Nacional de La Pampa, Avenida Uruguay 151, 6300, Santa Rosa, La Pampa, Argentina
| | - Alejandro Travaini
- Centro de Investigación de Puerto Deseado, Universidad Nacional de la Patagonia Austral, CONICET, Avenida Prefectura Naval s/n, 9050, Puerto Deseado, Santa Cruz, Argentina
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11
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Shao X, Lu Q, Xiong M, Bu H, Shi X, Wang D, Zhao J, Li S, Yao M. Prey partitioning and livestock consumption in the world's richest large carnivore assemblage. Curr Biol 2021; 31:4887-4897.e5. [PMID: 34551283 DOI: 10.1016/j.cub.2021.08.067] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 05/13/2021] [Accepted: 08/30/2021] [Indexed: 12/26/2022]
Abstract
Large mammalian carnivores have undergone catastrophic declines during the Anthropocene across the world. Despite their pivotal roles as apex predators in food webs and ecosystem dynamics, few detailed dietary datasets of large carnivores exist, prohibiting deep understanding of their coexistence and persistence in human-dominated landscapes. Here, we present fine-scaled, quantitative trophic interactions among sympatric carnivores from three assemblages in the Mountains of Southwest China, a global biodiversity hotspot harboring the world's richest large-carnivore diversity, derived from DNA metabarcoding of 1,097 fecal samples. These assemblages comprise a large-carnivore guild ranging from zero to five species along with two mesocarnivore species. We constructed predator-prey food webs for each assemblage and identified 95 vertebrate prey taxa and 260 feeding interactions in sum. Each carnivore species consumed 6-39 prey taxa, and dietary diversity decreased with increased carnivore body mass across guilds. Dietary partitioning was more evident between large-carnivore and mesocarnivore guilds, yet different large carnivores showed divergent proportional utilization of different-sized prey correlating with their own body masses. Large carnivores particularly selected livestock in Tibetan-dominated regions, where the indigenous people show high tolerance toward wild predators. Our results suggest that dietary niche partitioning and livestock subsidies facilitate large-carnivore sympatry and persistence and have key implications for sustainable conservation promoting human-carnivore coexistence.
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Affiliation(s)
- Xinning Shao
- School of Life Sciences, Peking University, Beijing 100871, China; Institute of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Qi Lu
- School of Life Sciences, Peking University, Beijing 100871, China; Institute of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Mengyin Xiong
- School of Life Sciences, Peking University, Beijing 100871, China
| | - Hongliang Bu
- School of Life Sciences, Peking University, Beijing 100871, China
| | - Xiaoyun Shi
- School of Life Sciences, Peking University, Beijing 100871, China; Institute of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Dajun Wang
- School of Life Sciences, Peking University, Beijing 100871, China
| | - Jindong Zhao
- School of Life Sciences, Peking University, Beijing 100871, China; Institute of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Sheng Li
- School of Life Sciences, Peking University, Beijing 100871, China; Institute of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.
| | - Meng Yao
- School of Life Sciences, Peking University, Beijing 100871, China; Institute of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.
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12
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Cambra M, Madrigal-Mora S, Chinchilla I, Golfín-Duarte G, Lowe CG, Espinoza M. First record of a potential neonate tiger shark (Galeocerdo cuvier) at a remote oceanic island in the Eastern Tropical Pacific. J Fish Biol 2021; 99:1140-1144. [PMID: 33942302 DOI: 10.1111/jfb.14774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 04/13/2021] [Accepted: 04/30/2021] [Indexed: 06/12/2023]
Abstract
Tiger sharks (Galeocerdo cuvier) play an important ecological role as top predators, yet knowledge of their reproductive ecology is scarce. Here, the authors report the first observation of a potential neonate G. cuvier at Cocos Island, a predator-dominated oceanic island in the Eastern Tropical Pacific (ETP). The individual was detected using baited remote underwater video stations (BRUVS). The cameras also detected female individuals potentially pregnant, suggesting that parturition may take place at or near the island. Nonetheless, it is still unclear if the presence of a single neonate is an isolated event or evidence that the species is using the island for reproduction.
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Affiliation(s)
- Marta Cambra
- Escuela de Biología, Universidad de Costa Rica, San José, Costa Rica
- Centro de Investigación en Ciencias del Mar y Limnología, Universidad de Costa Rica, San José, Costa Rica
| | - Sergio Madrigal-Mora
- Escuela de Biología, Universidad de Costa Rica, San José, Costa Rica
- Centro de Investigación en Ciencias del Mar y Limnología, Universidad de Costa Rica, San José, Costa Rica
| | - Isaac Chinchilla
- Parque Nacional Isla del Coco, Área de Conservación Marina Cocos (ACMC), Sistema Nacional de Áreas de Conservación, San José, Costa Rica
| | - Geiner Golfín-Duarte
- Parque Nacional Isla del Coco, Área de Conservación Marina Cocos (ACMC), Sistema Nacional de Áreas de Conservación, San José, Costa Rica
| | | | - Mario Espinoza
- Escuela de Biología, Universidad de Costa Rica, San José, Costa Rica
- Centro de Investigación en Ciencias del Mar y Limnología, Universidad de Costa Rica, San José, Costa Rica
- Museo de Zoología, Universidad de Costa Rica, San José, Costa Rica
- Migramar, Olema, California, USA
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13
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Vanbergen AJ, Boissieres C, Gray A, Chapman DS. Habitat loss, predation pressure and episodic heat-shocks interact to impact arthropods and photosynthetic functioning of microecosystems. Proc Biol Sci 2021; 288:20210032. [PMID: 33823665 PMCID: PMC8059533 DOI: 10.1098/rspb.2021.0032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 03/16/2021] [Indexed: 01/22/2023] Open
Abstract
Ecosystems face multiple, potentially interacting, anthropogenic pressures that can modify biodiversity and ecosystem functioning. Using a bryophyte-microarthropod microecosystem we tested the combined effects of habitat loss, episodic heat-shocks and an introduced non-native apex predator on ecosystem function (chlorophyll fluorescence as an indicator of photosystem II function) and microarthropod communities (abundance and body size). The photosynthetic function was degraded by the sequence of heat-shock episodes, but unaffected by microecosystem patch size or top-down pressure from the introduced predator. In small microecosystem patches without the non-native predator, Acari abundance decreased with heat-shock frequency, while Collembola abundance increased. These trends disappeared in larger microecosystem patches or when predators were introduced, although Acari abundance was lower in large patches that underwent heat-shocks and were exposed to the predator. Mean assemblage body length (Collembola) was reduced independently in small microecosystem patches and with greater heat-shock frequency. Our experimental simulation of episodic heatwaves, habitat loss and non-native predation pressure in microecosystems produced evidence of individual and potentially synergistic and antagonistic effects on ecosystem function and microarthropod communities. Such complex outcomes of interactions between multiple stressors need to be considered when assessing anthropogenic risks for biota and ecosystem functioning.
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Affiliation(s)
- Adam J. Vanbergen
- Agroécologie, AgroSup Dijon, INRAE, Univ. Bourgogne Franche-Comté, F-21000 Dijon, France
- UK Centre for Ecology and Hydrology, Bush Estate, Penicuik, Midlothian EH26 0QB, UK
| | - Claire Boissieres
- L'Ecole Nationale Supérieure Agronomique de Toulouse (ENSAT), Avenue de l'Agrobiopole, BP 32607, Auzeville-Tolosane 31326, Castanet-Tolosan, France
| | - Alan Gray
- UK Centre for Ecology and Hydrology, Bush Estate, Penicuik, Midlothian EH26 0QB, UK
| | - Daniel S. Chapman
- UK Centre for Ecology and Hydrology, Bush Estate, Penicuik, Midlothian EH26 0QB, UK
- Biological and Environmental Sciences, University of Stirling, Stirling FK9 4LA, UK
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14
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Cubaynes S, Aars J, Yoccoz NG, Pradel R, Wiig Ø, Ims RA, Gimenez O. Modeling the demography of species providing extended parental care: A capture-recapture multievent model with a case study on polar bears ( Ursus maritimus). Ecol Evol 2021; 11:3380-3392. [PMID: 33841791 PMCID: PMC8019049 DOI: 10.1002/ece3.7296] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 01/07/2021] [Accepted: 01/25/2021] [Indexed: 12/26/2022] Open
Abstract
In species providing extended parental care, one or both parents care for altricial young over a period including more than one breeding season. We expect large parental investment and long-term dependency within family units to cause high variability in life trajectories among individuals with complex consequences at the population level. So far, models for estimating demographic parameters in free-ranging animal populations mostly ignore extended parental care, thereby limiting our understanding of its consequences on parents and offspring life histories.We designed a capture-recapture multievent model for studying the demography of species providing extended parental care. It handles statistical multiple-year dependency among individual demographic parameters grouped within family units, variable litter size, and uncertainty on the timing at offspring independence. It allows for the evaluation of trade-offs among demographic parameters, the influence of past reproductive history on the caring parent's survival status, breeding probability, and litter size probability, while accounting for imperfect detection of family units. We assess the model performance using simulated data and illustrate its use with a long-term dataset collected on the Svalbard polar bears (Ursus maritimus).Our model performed well in terms of bias and mean square error and in estimating demographic parameters in all simulated scenarios, both when offspring departure probability from the family unit occurred at a constant rate or varied during the field season depending on the date of capture. For the polar bear case study, we provide estimates of adult and dependent offspring survival rates, breeding probability, and litter size probability. Results showed that the outcome of the previous reproduction influenced breeding probability.Overall, our results show the importance of accounting for i) the multiple-year statistical dependency within family units, ii) uncertainty on the timing at offspring independence, and iii) past reproductive history of the caring parent. If ignored, estimates obtained for breeding probability, litter size, and survival can be biased. This is of interest in terms of conservation because species providing extended parental care are often long-living mammals vulnerable or threatened with extinction.
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Affiliation(s)
- Sarah Cubaynes
- CEFEUniv MontpellierCNRSEPHE‐PSL UniversityIRDUniv Paul Valéry Montpellier 3MontpellierFrance
| | - Jon Aars
- Norwegian Polar InstituteFRAM CentreTromsøNorway
| | - Nigel G. Yoccoz
- Department of Arctic and Marine BiologyUiT The Arctic University of NorwayTromsøNorway
| | - Roger Pradel
- CEFEUniv MontpellierCNRSEPHE‐PSL UniversityIRDUniv Paul Valéry Montpellier 3MontpellierFrance
| | - Øystein Wiig
- Natural History MuseumUniversity of OsloOsloNorway
| | - Rolf A. Ims
- Department of Arctic and Marine BiologyUiT The Arctic University of NorwayTromsøNorway
| | - Olivier Gimenez
- CEFEUniv MontpellierCNRSEPHE‐PSL UniversityIRDUniv Paul Valéry Montpellier 3MontpellierFrance
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15
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Boessenecker RW, Churchill M, Buchholtz EA, Beatty BL, Geisler JH. Convergent Evolution of Swimming Adaptations in Modern Whales Revealed by a Large Macrophagous Dolphin from the Oligocene of South Carolina. Curr Biol 2020; 30:3267-3273.e2. [PMID: 32649912 DOI: 10.1016/j.cub.2020.06.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 05/25/2020] [Accepted: 06/02/2020] [Indexed: 11/18/2022]
Abstract
Modern whales and dolphins are superbly adapted for marine life, with tail flukes being a key innovation shared by all extant species. Some dolphins can exceed speeds of 50 km/h, a feat accomplished by thrusting the flukes while adjusting attack angle with their flippers [1]. These movements are driven by robust axial musculature anchored to a relatively rigid torso consisting of numerous short vertebrae, and controlled by hydrofoil-like flippers [2-7]. Eocene skeletons of whales illustrate the transition from semiaquatic to aquatic locomotion, including development of a fusiform body and reduction of hindlimbs [8-11], but the rarity of Oligocene whale skeletons [12, 13] has hampered efforts to understand the evolution of fluke-powered, but forelimb-controlled, locomotion. We report a nearly complete skeleton of the extinct large dolphin Ankylorhiza tiedemani comb. n. from the Oligocene of South Carolina, previously known only from a partial rostrum. Its forelimb is intermediate in morphology between stem cetaceans and extant taxa, whereas its axial skeleton displays incipient rigidity at the base of the tail with a flexible lumbar region. The position of Ankylorhiza near the base of the odontocete radiation implies that several postcranial specializations of extant cetaceans, including a shortened humerus, narrow peduncle, and loss of radial tuberosity, evolved convergently in odontocetes and mysticetes. Craniodental morphology, tooth wear, torso vertebral morphology, and body size all suggest that Ankylorhiza was a macrophagous predator that could swim relatively fast, indicating that it was one of the few extinct cetaceans to occupy a niche similar to that of killer whales.
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Affiliation(s)
- Robert W Boessenecker
- Department of Geology and Environmental Geosciences, College of Charleston, Charleston, SC 29424, USA; University of California Museum of Paleontology, University of California, Berkeley, CA 94720, USA.
| | - Morgan Churchill
- Department of Biology, University of Wisconsin-Oshkosh, Oshkosh, WI 54901, USA
| | - Emily A Buchholtz
- Department of Biological Sciences, Wellesley College, Wellesley, MA 02481, USA
| | - Brian L Beatty
- Department of Anatomy, College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, NY 11568, USA
| | - Jonathan H Geisler
- Department of Anatomy, College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, NY 11568, USA
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16
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Ellingsen KE, Yoccoz NG, Tveraa T, Frank KT, Johannesen E, Anderson MJ, Dolgov AV, Shackell NL. The rise of a marine generalist predator and the fall of beta diversity. Glob Chang Biol 2020; 26:2897-2907. [PMID: 32181966 DOI: 10.1111/gcb.15027] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 01/15/2020] [Indexed: 06/10/2023]
Abstract
Determining the importance of physical and biological drivers in shaping biodiversity in diverse ecosystems remains a global challenge. Advancements have been made towards this end in large marine ecosystems with several studies suggesting environmental forcing as the primary driver. However, both empirical and theoretical studies point to additional drivers of changes in diversity involving trophic interactions and, in particular, predation. Moreover, a more integrated but less common approach to the assessment of biodiversity changes involves analyses of spatial β diversity, whereas most studies to date assess only changes in species richness (α diversity). Recent research has established that when cod, a dominant generalist predator, was overfished and collapsed in a northwest Atlantic food web, spatial β diversity increased; that is, the spatial structure of the fish assemblage became increasingly heterogeneous. If cod were to recover, would this situation be reversible, given the inherent complexity and non-linear dynamics that typify such systems? A dramatic increase of cod in an ecologically similar large marine ecosystem may provide an answer. Here we show that spatial β diversity of fish assemblages in the Barents Sea decreased with increasing cod abundance, while decadal scale changes in temperature did not play a significant role. These findings indicate a reversibility of the fish assemblage structure in response to changing levels of an apex predator and highlight the frequently overlooked importance of trophic interactions in determining large-scale biodiversity patterns. As increased cod abundance was largely driven by changes in fisheries management, our study also shows that management policies and practices, particularly those involving apex predators, can have a strong effect in shaping spatial diversity patterns, and one should not restrict the focus to effects of climate change alone.
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Affiliation(s)
- Kari E Ellingsen
- Norwegian Institute for Nature Research (NINA), Fram Centre, Tromsø, Norway
| | - Nigel G Yoccoz
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
| | - Torkild Tveraa
- Norwegian Institute for Nature Research (NINA), Fram Centre, Tromsø, Norway
| | - Kenneth T Frank
- Ocean Sciences Division, Bedford Institute of Oceanography, Dartmouth, NS, Canada
| | | | - Marti J Anderson
- New Zealand Institute for Advanced Study (NZIAS), Albany Campus, Massey University, Auckland, New Zealand
| | - Andrey V Dolgov
- Polar Branch of the Federal State Budget Scientific Institution "Russian Federal Research Institute of Fisheries and Oceanography" ("PINRO" named after N.M. Knipovich), Murmansk, Russia
| | - Nancy L Shackell
- Ocean Sciences Division, Bedford Institute of Oceanography, Dartmouth, NS, Canada
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17
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Hartel T, Scheele BC, Vanak AT, Rozylowicz L, Linnell JDC, Ritchie EG. Mainstreaming human and large carnivore coexistence through institutional collaboration. Conserv Biol 2019; 33:1256-1265. [PMID: 30997704 DOI: 10.1111/cobi.13334] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Revised: 02/16/2019] [Accepted: 04/14/2019] [Indexed: 06/09/2023]
Abstract
Achieving coexistence between large carnivores and humans in human-dominated landscapes (HDLs) is a key challenge for societies globally. This challenge cannot be adequately met with the current sectoral approaches to HDL governance and an academic community largely dominated by disciplinary sectors. Academia (universities and other research institutions and organizations) should take a more active role in embracing societal challenges around conservation of large carnivores in HDLs by facilitating cross-sectoral cooperation to mainstream coexistence of humans and large carnivores. Drawing on lessons from populated regions of Europe, Asia, and South America with substantial densities of large carnivores, we suggest academia should better embrace the principles and methods of sustainability sciences and create institutional spaces for the implementation of transdisciplinary curricula and projects; reflect on research approaches (i.e., disciplinary, interdisciplinary, or transdisciplinary) they apply and how their outcomes could aid leveraging institutional transformations for mainstreaming; and engage with various institutions and stakeholder groups to create novel institutional structures that can respond to multiple challenges of HDL management and human-large carnivore coexistence. Success in mainstreaming this coexistence in HDL will rest on the ability to think and act cooperatively. Such a conservation achievement, if realized, stands to have far-reaching benefits for people and biodiversity.
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Affiliation(s)
- Tibor Hartel
- Hungarian Department of Biology and Ecology and Center of Systems Biology, Biodiversity and Bioresources (Center of '3B'), Babes-Bolyai University, Street Clinicilor 5-7, Cluj-Napoca, Romania
| | - Ben C Scheele
- Fenner School of Environment and Society, The Australian National University, Building 141, Linnaeus Way, Acton, ACT, 2601, Australia
| | - Abi Tamim Vanak
- Centre for Biodiversity and Conservation, ATREE, Bangalore, India
- Wellcome Trust/DBT India Alliance Program, Hyderabad, India
- School of Life Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Laurențiu Rozylowicz
- Centre for Environmental Research (CCMESI), University of Bucharest, 1 N. Balcescu, 010041, Bucharest, Romania
| | - John D C Linnell
- Norwegian Institute for Nature Research, P.O. Box 5685 Torgard, NO-7485, Trondheim, Norway
| | - Euan G Ritchie
- School of Life and Environmental Sciences, Centre for Integrative Ecology, Deakin University, Burwood, VIC, 3125, Australia
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18
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Sweeney OF, Turnbull J, Jones M, Letnic M, Newsome TM, Sharp A. An Australian perspective on rewilding. Conserv Biol 2019; 33:812-820. [PMID: 30693968 DOI: 10.1111/cobi.13280] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 10/18/2018] [Accepted: 11/22/2018] [Indexed: 06/09/2023]
Abstract
Rewilding is increasingly recognized as a conservation tool but is often context specific, which inhibits broad application. Rewilding in Australia seeks to enhance ecosystem function and promote self-sustaining ecosystems. An absence of large-bodied native herbivores means trophic rewilding in mainland Australia has focused on the restoration of functions provided by apex predators and small mammals. Because of the pervasive influence of introduced mesopredators, predator-proof fences, and establishment of populations on predator-free islands are common rewilding approaches. This sets Australian rewilding apart from most jurisdictions and provides globally relevant insights but presents challenges to restoring function to broader landscapes. Passive rewilding is of limited utility in arid zones. Although increasing habitat extent and quality in mesic coastal areas may work, it will likely be necessary to undertake active management. Because much of Australia's population is in urban areas, rewilding efforts must include urban areas to maximize effectiveness. Thus rewilding is not synonymous with wilderness and can occur over multiple scales. Rewilding efforts must recognize human effects on other species and benefit both nature and humans. Rewilding in Australia requires development of a shared vision and strategy and proof-of-concept projects to demonstrate the benefits. The repackaging of existing conservation activities as rewilding may confuse and undermine the success of rewilding programs and should be avoided. As elsewhere, rewilding in Australia should be viewed as an important conservation tool.
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Affiliation(s)
- Oisín F Sweeney
- National Parks Association of New South Wales, Pyrmont, NSW, 2009, Australia
| | - John Turnbull
- Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Menna Jones
- School of Biological Sciences, University of Tasmania, Hobart, TAS, 7001, Australia
| | - Mike Letnic
- Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Thomas M Newsome
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Andy Sharp
- Natural Resources Northern and Yorke, Clare, SA, 5453, Australia
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19
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Chang CT, Chiang WC, Chang YC, Musyl MK, Sun CL, Madigan DJ, Carlisle AB, Hsu HH, Chang QX, Su NJ, Ho YS, Tseng CT. Stable isotope analysis reveals ontogenetic feeding shifts in Pacific blue marlin (Makaira nigricans) off eastern Taiwan. J Fish Biol 2019; 94:958-965. [PMID: 30671958 DOI: 10.1111/jfb.13902] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 01/21/2019] [Indexed: 06/09/2023]
Abstract
To gain a better understanding of the trophic ecology of Pacific blue marlin Makaira nigricans off eastern Taiwan, nitrogen and carbon stable isotopes (δ15 N and δ13 C) and Bayesian mixing models were used to explore trophic dynamics and potential ontogenetic feeding shifts across M. nigricans of different size classes. Makaira nigricans samples from east of Taiwan (n = 213) and Palau (n = 37), as well as their prey (n = 70), were collected during 2012 and 2013. Results indicated increases in δ15 N with size, with values of larger size classes (> 200 cm eye-to-fork length; LEF ) significantly higher than those < 200 cm LEF . Values of δ13 C were negatively correlated with size. Makaira nigricans > 200 cm LEF had the highest estimated trophic position (4.44) and also exhibited ontogenetic changes in trophic position. Large M. nigricans fed more on dolphinfish Coryphaena hippurus and hairtail Trichiurus lepturus, while smaller M. nigricans consumed smaller forage fish (e.g., moonfish Mene maculata) and cephalopods. These changes may relate to greater swimming speeds and vertical habitat use in larger M. nigricans, allowing capture and consumption of larger prey items at higher trophic positions. The high trophic level of M. nigricans east of Taiwan confirms its important role as an apex predator in marine food webs and how ecological role changes with size.
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Affiliation(s)
- Ching-Tsun Chang
- Eastern Marine Biology Research Center, Fisheries Research Institute, Taitung, Taiwan
| | - Wei-Chuan Chiang
- Eastern Marine Biology Research Center, Fisheries Research Institute, Taitung, Taiwan
| | - Yun-Chen Chang
- Institute of Oceanography, National Taiwan University, Taipei, Taiwan
| | | | - Chi-Lu Sun
- Institute of Oceanography, National Taiwan University, Taipei, Taiwan
- Center of Excellent for the Oceans, National Taiwan Ocean University, Keelung, Taiwan
| | - Daniel J Madigan
- Gulf of California International Research Center, Santa Rosalia, Mexico
| | - Aaron B Carlisle
- School of Marine Science and Policy, University of Delaware, Lewes, Delaware, USA
| | - Hung-Hung Hsu
- Eastern Marine Biology Research Center, Fisheries Research Institute, Taitung, Taiwan
| | - Qi-Xuan Chang
- Department of Environmental Biology and Fishery Science, National Taiwan Ocean University, Keelung, Taiwan
| | - Nan-Jay Su
- Department of Environmental Biology and Fishery Science, National Taiwan Ocean University, Keelung, Taiwan
| | - Yuan-Shing Ho
- Eastern Marine Biology Research Center, Fisheries Research Institute, Taitung, Taiwan
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Farr MT, Green DS, Holekamp KE, Roloff GJ, Zipkin EF. Multispecies hierarchical modeling reveals variable responses of African carnivores to management alternatives. Ecol Appl 2019; 29:e01845. [PMID: 30694574 DOI: 10.1002/eap.1845] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 09/11/2018] [Accepted: 12/04/2018] [Indexed: 06/09/2023]
Abstract
Carnivore communities face unprecedented threats from humans. Yet, management regimes have variable effects on carnivores, where species may persist or decline in response to direct or indirect changes to the ecosystem. Using a hierarchical multispecies modeling approach, we examined the effects of alternative management regimes (i.e., active vs. passive enforcement of regulations) on carnivore abundances and group sizes at both species and community levels in the Masai Mara National Reserve, Kenya. Alternative management regimes have created a dichotomy in ecosystem conditions within the Reserve, where active enforcement of regulations maintains low levels of human disturbance in the Mara Triangle and passive enforcement of regulations in the Talek region permits multiple forms of human disturbance. Our results demonstrate that these alternative management regimes have variable effects on 11 observed carnivore species. As predicted, some species, such as African lions and bat-eared foxes, have higher population densities in the Mara Triangle, where regulations are actively enforced. Yet, other species, including black-backed jackals and spotted hyenas, have higher population densities in the Talek region where enforcement is passive. Multiple underlying mechanisms, including behavioral plasticity and competitive release, are likely causing higher black-backed jackals and spotted hyena densities in the disturbed Talek region. Our multispecies modeling framework reveals that carnivores do not react to management regimes uniformly, shaping carnivore communities by differentially producing winning and losing species. Some carnivore species require active enforcement of regulations for effective conservation, while others more readily adapt (and in some instances thrive in response) to lax management enforcement and resulting anthropogenic disturbance. Yet, high levels of human disturbance appear to be negatively affecting the majority of carnivores, with potential consequences that may permeate throughout the rest of the ecosystem. Community approaches to monitoring carnivores should be adopted as single species monitoring may overlook important intra-community variability.
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Affiliation(s)
- Matthew T Farr
- Department of Integrative Biology, Michigan State University, East Lansing, Michigan, 48824, USA
- Ecology, Evolutionary Biology, and Behavior Program, Michigan State University, East Lansing, Michigan, 48824, USA
| | - David S Green
- Department of Integrative Biology, Michigan State University, East Lansing, Michigan, 48824, USA
- Ecology, Evolutionary Biology, and Behavior Program, Michigan State University, East Lansing, Michigan, 48824, USA
- Institute for Natural Resources, Oregon State University, Corvallis, Oregon, 97331, USA
| | - Kay E Holekamp
- Department of Integrative Biology, Michigan State University, East Lansing, Michigan, 48824, USA
- Ecology, Evolutionary Biology, and Behavior Program, Michigan State University, East Lansing, Michigan, 48824, USA
| | - Gary J Roloff
- Ecology, Evolutionary Biology, and Behavior Program, Michigan State University, East Lansing, Michigan, 48824, USA
- Department of Fisheries and Wildlife, Michigan State University, East Lansing, Michigan, 48824, USA
| | - Elise F Zipkin
- Department of Integrative Biology, Michigan State University, East Lansing, Michigan, 48824, USA
- Ecology, Evolutionary Biology, and Behavior Program, Michigan State University, East Lansing, Michigan, 48824, USA
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21
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Reglero P, Ortega A, Balbín R, Abascal FJ, Medina A, Blanco E, de la Gándara F, Alvarez-Berastegui D, Hidalgo M, Rasmuson L, Alemany F, Fiksen Ø. Atlantic bluefin tuna spawn at suboptimal temperatures for their offspring. Proc Biol Sci 2019; 285:rspb.2017.1405. [PMID: 29321292 DOI: 10.1098/rspb.2017.1405] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 12/04/2017] [Indexed: 11/12/2022] Open
Abstract
Life-history traits such as spawning migrations and timing of reproduction are adaptations to specific environmental constraints and seasonal cycles in many organisms' annual routines. In this study we analyse how offspring fitness constrains spawning phenology in a large migratory apex predator, the Atlantic bluefin tuna. The reproductive schedule of Atlantic bluefin tuna varies between spawning sites, suggesting plasticity to local environmental conditions. Generally, temperature is considered to be the main constraint on tuna spawning phenology. We combine evidence from long-term field data, temperature-controlled rearing experiments on eggs and larvae, and a model of egg fitness, and show that Atlantic bluefin tuna do not spawn to optimize egg and larval temperature exposure. The timing of spawning leads to temperature exposure considerably lower than optimal at all spawning grounds across the Atlantic Ocean. The early spawning is constrained by thermal inhibition of egg hatching and larval growth rates, but some other factors must prevent later spawning. Matching offspring with ocean productivity and the prey peak might be an important driver for bluefin tuna spawning phenology. This finding is important for predictions of reproductive timing in future climate warming scenarios for bluefin tuna.
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Affiliation(s)
- P Reglero
- Instituto Español de Oceanografía, Centre Oceanogràfic de les Balears, Moll de Ponent s/n, 07015 Palma de Mallorca, Spain
| | - A Ortega
- Instituto Español de Oceanografía, Centro Oceanográfico de Murcia, 30860 Puerto de Mazarrón, Murcia, Spain
| | - R Balbín
- Instituto Español de Oceanografía, Centre Oceanogràfic de les Balears, Moll de Ponent s/n, 07015 Palma de Mallorca, Spain
| | - F J Abascal
- Instituto Español de Oceanografía, Centro Oceanográfico de Canarias, 38180 Santa Cruz de Tenerife, Spain
| | - A Medina
- Departamento de Biología, Facultad de Ciencias del Mar y Ambientales, Avda. República Saharaui, s/n, 11510 Puerto Real, Cádiz, Spain
| | - E Blanco
- Instituto Español de Oceanografía, Centre Oceanogràfic de les Balears, Moll de Ponent s/n, 07015 Palma de Mallorca, Spain
| | - F de la Gándara
- Instituto Español de Oceanografía, Centro Oceanográfico de Murcia, 30860 Puerto de Mazarrón, Murcia, Spain
| | - D Alvarez-Berastegui
- Balearic Islands Coastal Observing and Forecasting System, Parc Bit, Naorte, Bloc A 2°p. pta 3, Palma de Mallorca, Balearic Islands, Spain
| | - M Hidalgo
- Instituto Español de Oceanografía, Centre Oceanogràfic de les Balears, Moll de Ponent s/n, 07015 Palma de Mallorca, Spain
| | - L Rasmuson
- Marine Resources Program, Oregon Department of Fish and Wildlife, 2040 SE Marine Science Drive, Newport, OR, USA.,National Oceanic and Atmospheric Administration, Southeast Fisheries Science Center, Miami, FL 33149, USA
| | - F Alemany
- Instituto Español de Oceanografía, Centre Oceanogràfic de les Balears, Moll de Ponent s/n, 07015 Palma de Mallorca, Spain
| | - Ø Fiksen
- Department of Biology, University of Bergen, 5020 Bergen, Norway
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22
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Morris T, Letnic M. Removal of an apex predator initiates a trophic cascade that extends from herbivores to vegetation and the soil nutrient pool. Proc Biol Sci 2018; 284:rspb.2017.0111. [PMID: 28490624 DOI: 10.1098/rspb.2017.0111] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 04/13/2017] [Indexed: 11/12/2022] Open
Abstract
It is widely assumed that organisms at low trophic levels, particularly microbes and plants, are essential to basic services in ecosystems, such as nutrient cycling. In theory, apex predators' effects on ecosystems could extend to nutrient cycling and the soil nutrient pool by influencing the intensity and spatial organization of herbivory. Here, we take advantage of a long-term manipulation of dingo abundance across Australia's dingo-proof fence in the Strzelecki Desert to investigate the effects that removal of an apex predator has on herbivore abundance, vegetation and the soil nutrient pool. Results showed that kangaroos were more abundant where dingoes were rare, and effects of kangaroo exclusion on vegetation, and total carbon, total nitrogen and available phosphorus in the soil were marked where dingoes were rare, but negligible where dingoes were common. By showing that a trophic cascade resulting from an apex predator's lethal effects on herbivores extends to the soil nutrient pool, we demonstrate a hitherto unappreciated pathway via which predators can influence nutrient dynamics. A key implication of our study is the vast spatial scale across which apex predators' effects on herbivore populations operate and, in turn, effects on the soil nutrient pool and ecosystem productivity could become manifest.
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Affiliation(s)
- Timothy Morris
- Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Mike Letnic
- Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
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23
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French GCA, Stürup M, Rizzuto S, van Wyk JH, Edwards D, Dolan RW, Wintner SP, Towner AV, Hughes WOH. The tooth, the whole tooth and nothing but the tooth: tooth shape and ontogenetic shift dynamics in the white shark Carcharodon carcharias. J Fish Biol 2017; 91:1032-1047. [PMID: 28815588 DOI: 10.1111/jfb.13396] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 07/18/2017] [Indexed: 06/07/2023]
Abstract
Results from this study of the white shark Carcharodon carcharias include measurements obtained using a novel photographic method that reveal significant differences between the sexes in the relationship between tooth cuspidity and shark total length, and a novel ontogenetic change in male tooth shape. Males exhibit broader upper first teeth and increased distal inclination of upper third teeth with increasing length, while females do not present a consistent morphological change. Substantial individual variation, with implications for pace of life syndrome, was present in males and tooth polymorphism was suggested in females. Sexual differences and individual variation may play major roles in ontogenetic changes in tooth morphology in C. carcharias, with potential implications for their foraging biology. Such individual and sexual differences should be included in studies of ontogenetic shift dynamics in other species and systems.
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Affiliation(s)
- G C A French
- School of Life Sciences, University of Sussex, Brighton, BN1 9QG, U.K
| | - M Stürup
- School of Life Sciences, University of Sussex, Brighton, BN1 9QG, U.K
| | - S Rizzuto
- Department of Botany and Zoology, Stellenbosch University, Stellenbosch, 7600, South Africa
| | - J H van Wyk
- Department of Botany and Zoology, Stellenbosch University, Stellenbosch, 7600, South Africa
| | - D Edwards
- Dyer Island Conservation Trust, Kleinbaai, South Africa
| | - R W Dolan
- Dyer Island Conservation Trust, Kleinbaai, South Africa
| | - S P Wintner
- KwaZulu-Natal Sharks Board and Biomedical Resource Unit, University of KwaZulu-Natal, Durban, 4000, South Africa
| | - A V Towner
- Dyer Island Conservation Trust, Kleinbaai, South Africa
| | - W O H Hughes
- School of Life Sciences, University of Sussex, Brighton, BN1 9QG, U.K
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24
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Berry TE, Osterrieder SK, Murray DC, Coghlan ML, Richardson AJ, Grealy AK, Stat M, Bejder L, Bunce M. DNA metabarcoding for diet analysis and biodiversity: A case study using the endangered Australian sea lion ( Neophoca cinerea). Ecol Evol 2017; 7:5435-5453. [PMID: 28770080 PMCID: PMC5528208 DOI: 10.1002/ece3.3123] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 04/12/2017] [Accepted: 05/08/2017] [Indexed: 11/10/2022] Open
Abstract
The analysis of apex predator diet has the ability to deliver valuable insights into ecosystem health, and the potential impacts a predator might have on commercially relevant species. The Australian sea lion (Neophoca cinerea) is an endemic apex predator and one of the world's most endangered pinnipeds. Given that prey availability is vital to the survival of top predators, this study set out to understand what dietary information DNA metabarcoding could yield from 36 sea lion scats collected across 1,500 km of its distribution in southwest Western Australia. A combination of PCR assays were designed to target a variety of potential sea lion prey, including mammals, fish, crustaceans, cephalopods, and birds. Over 1.2 million metabarcodes identified six classes from three phyla, together representing over 80 taxa. The results confirm that the Australian sea lion is a wide-ranging opportunistic predator that consumes an array of mainly demersal fauna. Further, the important commercial species Sepioteuthis australis (southern calamari squid) and Panulirus cygnus (western rock lobster) were detected, but were present in <25% of samples. Some of the taxa identified, such as fish, sharks and rays, clarify previous knowledge of sea lion prey, and some, such as eel taxa and two gastropod species, represent new dietary insights. Even with modest sample sizes, a spatial analysis of taxa and operational taxonomic units found within the scat shows significant differences in diet between many of the sample locations and identifies the primary taxa that are driving this variance. This study provides new insights into the diet of this endangered predator and confirms the efficacy of DNA metabarcoding of scat as a noninvasive tool to more broadly define regional biodiversity.
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Affiliation(s)
- Tina E. Berry
- Trace and Environmental DNA (TrEnD) LaboratoryDepartment of Environment and AgricultureCurtin UniversityBentleyWAAustralia
| | | | - Dáithí C. Murray
- Trace and Environmental DNA (TrEnD) LaboratoryDepartment of Environment and AgricultureCurtin UniversityBentleyWAAustralia
| | - Megan L. Coghlan
- Trace and Environmental DNA (TrEnD) LaboratoryDepartment of Environment and AgricultureCurtin UniversityBentleyWAAustralia
| | | | - Alicia K. Grealy
- Trace and Environmental DNA (TrEnD) LaboratoryDepartment of Environment and AgricultureCurtin UniversityBentleyWAAustralia
| | - Michael Stat
- Trace and Environmental DNA (TrEnD) LaboratoryDepartment of Environment and AgricultureCurtin UniversityBentleyWAAustralia
| | - Lars Bejder
- Cetacean Research UnitMurdoch UniversityMurdochWAAustralia
| | - Michael Bunce
- Trace and Environmental DNA (TrEnD) LaboratoryDepartment of Environment and AgricultureCurtin UniversityBentleyWAAustralia
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26
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Stier AC, Samhouri JF, Novak M, Marshall KN, Ward EJ, Holt RD, Levin PS. Ecosystem context and historical contingency in apex predator recoveries. Sci Adv 2016; 2:e1501769. [PMID: 27386535 PMCID: PMC4928970 DOI: 10.1126/sciadv.1501769] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 04/30/2016] [Indexed: 05/28/2023]
Abstract
Habitat loss, overexploitation, and numerous other stressors have caused global declines in apex predators. This "trophic downgrading" has generated widespread concern because of the fundamental role that apex predators can play in ecosystem functioning, disease regulation, and biodiversity maintenance. In attempts to combat declines, managers have conducted reintroductions, imposed stricter harvest regulations, and implemented protected areas. We suggest that full recovery of viable apex predator populations is currently the exception rather than the rule. We argue that, in addition to well-known considerations, such as continued exploitation and slow life histories, there are several underappreciated factors that complicate predator recoveries. These factors include three challenges. First, a priori identification of the suite of trophic interactions, such as resource limitation and competition that will influence recovery can be difficult. Second, defining and accomplishing predator recovery in the context of a dynamic ecosystem requires an appreciation of the timing of recovery, which can determine the relative density of apex predators and other predators and therefore affect competitive outcomes. Third, successful recovery programs require designing adaptive sequences of management strategies that embrace key environmental and species interactions as they emerge. Consideration of recent research on food web modules, alternative stable states, and community assembly offer important insights for predator recovery efforts and restoration ecology more generally. Foremost among these is the importance of a social-ecological perspective in facilitating a long-lasting predator restoration while avoiding unintended consequences.
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Affiliation(s)
- Adrian C. Stier
- National Center for Ecological Analysis and Synthesis, 735 State Street, Santa Barbara, CA 93101, USA
- School of Aquatic and Fishery Sciences, University of Washington, 1122 Northeast Boat Street, Seattle, WA 98105, USA
| | - Jameal F. Samhouri
- Conservation Biology Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, WA 98112, USA
| | - Mark Novak
- Department of Integrative Biology, Oregon State University, Corvallis, OR 97331, USA
| | - Kristin N. Marshall
- Conservation Biology Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, WA 98112, USA
| | - Eric J. Ward
- Conservation Biology Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, WA 98112, USA
| | - Robert D. Holt
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Phillip S. Levin
- Conservation Biology Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, WA 98112, USA
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27
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Hughes MR, Dodd JA, Maitland PS, Adams CE. Lake bathymetry and species occurrence predict the distribution of a lacustrine apex predator. J Fish Biol 2016; 88:1648-54. [PMID: 26899559 DOI: 10.1111/jfb.12919] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 01/20/2016] [Indexed: 05/25/2023]
Abstract
This study examined the abiotic and biotic characteristics of ecosystems that allow expression of a life history called ferox trout, the colloquial name given to brown trout Salmo trutta adopting a piscivorous life history strategy, an apex predator in post-glacial lakes in northern Europe. One hundred and ninety-two lakes in Scotland show evidence of currently, or historically, supporting ferox S. trutta; their presence was predicted in logistic models by larger and deeper lakes with a large catchment that also support populations of Arctic charr Salvelinus alpinus.
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Affiliation(s)
- M R Hughes
- Scottish Centre for Ecology and the Natural Environment, Institute of Biomedical and Life Sciences, University of Glasgow, Loch Lomond, Glasgow, G63 OAW, Scotland, U.K
| | - J A Dodd
- Scottish Centre for Ecology and the Natural Environment, Institute of Biomedical and Life Sciences, University of Glasgow, Loch Lomond, Glasgow, G63 OAW, Scotland, U.K
| | - P S Maitland
- Fish Conservation Centre, Gladshot, Haddington, East Lothian, EH41 4NR, Scotland, U.K
| | - C E Adams
- Scottish Centre for Ecology and the Natural Environment, Institute of Biomedical and Life Sciences, University of Glasgow, Loch Lomond, Glasgow, G63 OAW, Scotland, U.K
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28
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Hill NJ, Tobin AJ, Reside AE, Pepperell JG, Bridge TCL. Dynamic habitat suitability modelling reveals rapid poleward distribution shift in a mobile apex predator. Glob Chang Biol 2016; 22:1086-96. [PMID: 26464050 DOI: 10.1111/gcb.13129] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 09/26/2015] [Accepted: 09/28/2015] [Indexed: 05/05/2023]
Abstract
Many taxa are undergoing distribution shifts in response to anthropogenic climate change. However, detecting a climate signal in mobile species is difficult due to their wide-ranging, patchy distributions, often driven by natural climate variability. For example, difficulties associated with assessing pelagic fish distributions have rendered fisheries management ill-equipped to adapt to the challenges posed by climate change, leaving pelagic species and ecosystems vulnerable. Here, we demonstrate the value of citizen science data for modelling the dynamic habitat suitability of a mobile pelagic predator (black marlin, Istiompax indica) within the south-west Pacific Ocean. The extensive spatial and temporal coverage of our occurrence data set (n = 18 717), collected at high resolution (~1.85 km(2) ), enabled identification of suitable habitat at monthly time steps over a 16-year period (1998-2013). We identified considerable monthly, seasonal and interannual variability in the extent and distribution of suitable habitat, predominately driven by chlorophyll a and sea surface height. Interannual variability correlated with El Nino Southern Oscillation (ENSO) events, with suitable habitat extending up to ~300 km further south during La Nina events. Despite the strong influence of ENSO, our model revealed a rapid poleward shift in the geometric mean of black marlin habitat, occurring at 88.2 km decade(-1) . By incorporating multiple environmental factors at monthly time steps, we were able to demonstrate a rapid distribution shift in a mobile pelagic species. Our findings suggest that the rapid velocity of climate change in the south-west Pacific Ocean is likely affecting mobile pelagic species, indicating that they may be more vulnerable to climate change than previously thought.
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Affiliation(s)
- Nicholas J Hill
- Centre for Sustainable Tropical Fisheries and Aquaculture, College of Marine and Environmental Sciences, James Cook University, Townsville, Qld, 4811, Australia
| | - Andrew J Tobin
- Centre for Sustainable Tropical Fisheries and Aquaculture, College of Marine and Environmental Sciences, James Cook University, Townsville, Qld, 4811, Australia
| | - April E Reside
- Centre for Tropical Environmental and Sustainability Sciences, College of Marine and Environmental Sciences, James Cook University, Townsville, Qld, 4811, Australia
| | - Julian G Pepperell
- Pepperell Research and Consulting Pty Ltd., P.O. Box 1475, Noosaville DC, Qld, 4566, Australia
| | - Tom C L Bridge
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Qld, 4811, Australia
- Australian Institute of Marine Science, PMB #3, Townsville MC, Qld, 4810, Australia
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29
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Colman NJ, Gordon CE, Crowther MS, Letnic M. Lethal control of an apex predator has unintended cascading effects on forest mammal assemblages. Proc Biol Sci 2014; 281:20133094. [PMID: 24619441 DOI: 10.1098/rspb.2013.3094] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Disruption to species-interaction networks caused by irruptions of herbivores and mesopredators following extirpation of apex predators is a global driver of ecosystem reorganization and biodiversity loss. Most studies of apex predators' ecological roles focus on effects arising from their interactions with herbivores or mesopredators in isolation, but rarely consider how the effects of herbivores and mesopredators interact. Here, we provide evidence that multiple cascade pathways induced by lethal control of an apex predator, the dingo, drive unintended shifts in forest ecosystem structure. We compared mammal assemblages and understorey structure at seven sites in southern Australia. Each site comprised an area where dingoes were poisoned and an area without control. The effects of dingo control on mammals scaled with body size. Activity of herbivorous macropods, arboreal mammals and a mesopredator, the red fox, were greater, but understorey vegetation sparser and abundances of small mammals lower, where dingoes were controlled. Structural equation modelling suggested that both predation by foxes and depletion of understorey vegetation by macropods were related to small mammal decline at poisoned sites. Our study suggests that apex predators' suppressive effects on herbivores and mesopredators occur simultaneously and should be considered in tandem in order to appreciate the extent of apex predators' indirect effects.
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Affiliation(s)
- N J Colman
- Hawkesbury Institute for the Environment, University of Western Sydney, , Locked Bag 1797, Penrith, New South Wales 2751, Australia, School of Biological Sciences, University of Sydney, , Sydney, New South Wales 2006, Australia, Centre for Ecosystem Science, University of New South Wales, , Sydney, New South Wales 2052, Australia, School of Biological, Earth and Environmental Sciences, University of New South Wales, , Sydney, New South Wales 2052, Australia
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30
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Tsai CN, Chiang WC, Sun CL, Shao KT, Chen SY, Yeh SZ. Trophic size-structure of sailfish Istiophorus platypterus in eastern Taiwan estimated by stable isotope analysis. J Fish Biol 2014; 84:354-371. [PMID: 24447322 DOI: 10.1111/jfb.12290] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Accepted: 10/26/2013] [Indexed: 06/03/2023]
Abstract
To examine trophic dynamics over different size classes, an isotopic study of sailfish Istiophorus platypterus life-history stages was carried out. Samples were collected from eastern Taiwan and the South China Sea during April 2009 and February 2012. A total of 263 samples (111-245 cm, lower jaw fork length, LLJFL ) were examined for changes in trophic structure in relation to LLJFL by using stable isotope analysis of carbon (δ(13) C) and nitrogen (δ(15) N). The δ(15) N values for I. platypterus ranged from 7·51 to 14·19‰ (mean ± s.d. = 12·06 ± 1·16‰) and the δ(13) C values ranged from -22·04 to -15·48‰ (mean ± s.d. = -17·62 ± 1·10‰). The δ(15) N values were positively dependent on LLJFL (r(2) = 0·377), whereas δ(13) C were negatively dependent on LLJFL (r(2) = 0·063). There were significantly different seasonal changes in nitrogen and carbon isotopic concentration, but no significant differences in concentrations between eastern Taiwan and the South China Sea were reported. The trophic level (TL ) of each LLJFL class was correlated, starting from 2·84 TL for size class I (LLJFL < 140 cm) and reaching 5·03 TL for size class VI (LLJFL > 221 cm). The mean ± s.d. TL was 4·43 ± 0·19 for all samples. The results reveal that I. platypterus occupies a wide range of trophic levels and different size classes occupy different trophic positions in the pelagic ecosystem.
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Affiliation(s)
- C-N Tsai
- Institute of Oceanography, National Taiwan University, 1 Sec. 4 Roosevelt Road, Taipei 106, Taiwan
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