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Cairncross RJ, Spencer EE, Meisuria N, Crowther MS, Newsome TM. Carrion use by a reptile is influenced by season, habitat and competition with an apex mammalian scavenger. Ecol Evol 2024; 14:e70211. [PMID: 39206457 PMCID: PMC11350275 DOI: 10.1002/ece3.70211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2024] [Revised: 07/31/2024] [Accepted: 08/09/2024] [Indexed: 09/04/2024] Open
Abstract
Scavenging on carrion is critical and often fiercely competitive for a range of vertebrate species, from native apex predators to invasive species and even reptiles. Within Australia, a notable reptilian scavenger is the lace monitor (Varanus varius). In this study, we quantified lace monitor activity at carcasses and compared their use of the resource to common co-occurring predators that also scavenge; the invasive red fox (Vulpes vulpes) and a native apex predator, the dingo (Canis dingo). To do so, we deployed 80 macropod carcasses equally across seasons (summer and winter) and habitats (open and closed canopy) in a temperate bioregion and monitored vertebrate scavenging with camera traps. Lace monitor activity (visitation at carcass sites inclusive of both non-scavenging and scavenging events) was 1.67 times higher in summer than in winter, but it did not differ across closed and open habitats. Monitor activity occurred earlier after carcass deployment at sites deployed in summer than winter (1.47-fold earlier), and at carcasses in open than closed habitats (0.22-fold earlier). Lace monitors initially discovered carcass sites faster in summer than winter and before both red foxes and dingoes in summer. The species was active diurnally in both summer and winter, differing from the red fox, which was strictly a nocturnal scavenger and the dingo, which was significantly more active at night across both seasons. Finally, we found that lace monitor activity at carcass sites decreased slightly with higher rates of activity for dingoes (0.04-fold decrease as dingo activity increased), but not with red fox activity. Our results have implications for understanding lace monitor foraging and scavenging and highlight the value of monitoring carcasses to provide important insights into the behaviour of varanid lizards that scavenge.
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Affiliation(s)
- Rhys J. Cairncross
- School of Life and Environmental ScienceThe University of SydneySydneyNew South WalesAustralia
| | - Emma E. Spencer
- School of Life and Environmental ScienceThe University of SydneySydneyNew South WalesAustralia
| | - Niraj Meisuria
- School of Life and Environmental ScienceThe University of SydneySydneyNew South WalesAustralia
| | - Mathew S. Crowther
- School of Life and Environmental ScienceThe University of SydneySydneyNew South WalesAustralia
| | - Thomas M. Newsome
- School of Life and Environmental ScienceThe University of SydneySydneyNew South WalesAustralia
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Lu Q, Cheng C, Xiao L, Li J, Li X, Zhao X, Lu Z, Zhao J, Yao M. Food webs reveal coexistence mechanisms and community organization in carnivores. Curr Biol 2023; 33:647-659.e5. [PMID: 36669497 DOI: 10.1016/j.cub.2022.12.049] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 11/11/2022] [Accepted: 12/20/2022] [Indexed: 01/20/2023]
Abstract
Globally, massive carnivore guild extirpations have led to trophic downgrading and compromised ecosystem services. However, the complexity of multi-carnivore food webs complicates accurate identification of species interactions and community organization. Here, we used fecal DNA metabarcoding to investigate three communities that together encompass eight large- and meso-carnivore species and their 44 prey taxa of the Qinghai-Tibet Plateau (QTP), one of the last places on Earth that still harbors intact carnivore assemblages. Quantitative food-web analyses revealed pronounced interspecific variations in the carnivores' prey compositions and dietary partitioning both between and within guilds. Additionally, body masses of the carnivores and their prey exhibited consistent hump-shaped correlations across communities. Overall, differences in prey diversity, size category, and proportional utilization among the carnivore species result in trophic niche segregation that likely promotes carnivore coexistence in the harsh QTP environment. Network structure analyses detected significant modularity in all food webs but nestedness in only one. Furthermore, network characterization identified pikas (Ochotona spp.), bharal (Pseudois nayaur), and domestic yak (Bos grunniens) as potential keystone prey across the areas. Our results paint a holistic and detailed picture of the QTP carnivore assemblages' trophic networks and demonstrate that the combined use of the molecular dietary approach and network analysis can generate structural insights into carnivore coexistence and can identify functionally important species in complex communities. Such knowledge can help safeguard carnivore guild integrity and enhance community resilience to environmental perturbations in the sensitive QTP ecosystems.
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Affiliation(s)
- 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
| | - Chen Cheng
- Center for Nature and Society, School of Life Sciences, Peking University, Beijing 100871, China; Shan Shui Conservation Center, Beijing 100871, China
| | - Lingyun Xiao
- School of Life Sciences, Peking University, Beijing 100871, China; Department of Health and Environmental Sciences, Xi'an Jiaotong Liverpool University, Suzhou, Jiangsu 215123, China
| | - Juan Li
- School of Life Sciences, Peking University, Beijing 100871, China; Department of Health and Environmental Sciences, Xi'an Jiaotong Liverpool University, Suzhou, Jiangsu 215123, China
| | - Xueyang Li
- School of Life Sciences, Peking University, Beijing 100871, China
| | - Xiang Zhao
- Shan Shui Conservation Center, Beijing 100871, China
| | - Zhi Lu
- School of Life Sciences, Peking University, Beijing 100871, China; Institute of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China; Center for Nature and Society, School of Life Sciences, Peking University, Beijing 100871, China; Shan Shui Conservation Center, 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
| | - 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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Bandyopadhyay M, Burton AC, Gupta SK, Krishnamurthy R. Understanding the distribution and fine-scale habitat selection of mesocarnivores along a habitat quality gradient in western Himalaya. PeerJ 2022; 10:e13993. [PMID: 36132214 PMCID: PMC9484455 DOI: 10.7717/peerj.13993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 08/11/2022] [Indexed: 01/20/2023] Open
Abstract
Background: Human activities have resulted in a rapid increase of modified habitats in proximity to wildlife habitats in the Himalaya. However, it is crucial to understand the extent to which human habitat modification affects wildlife. Mesocarnivores generally possess broader niches than large carnivores and adapt quickly to human activities. Here, we use a case study in the western Himalaya to test the hypothesis that human disturbance influenced mesocarnivore habitat use. Methods: We used camera trapping and mitochondrial DNA-based species identification from faecal samples to obtain mesocarnivore detections. We then compared the responses of mesocarnivores between an anthropogenic site and a less disturbed park along a contiguous gradient in habitat quality. The non-linear pattern in species-specific habitat selection and factors responsible for space usage around villages was captured using hierarchical generalized additive modelling (HGAM) and non-metric multidimensional scaling (NMDS) ordination. Results: Wildlife occurrences along the gradient varied by species. Leopard cat and red fox were the only terrestrial mesocarnivores that occurred in both anthropogenic site and park. We found a shift in habitat selection from less disturbed habitat in the park to disturbed habitat in anthropogenic site for the species detected in both the habitat types. For instance, red fox showed habitat selection towards high terrain ruggedness (0.5 to 0.7 TRI) and low NDVI (-0.05 to 0.2) in the park but no such specific selection in anthropogenic site. Further, leopard cat showed habitat selection towards moderate slope (20°) and medium NDVI (0.5) in park but no prominent habitat selections in anthropogenic site. The results revealed their constrained behaviour which was further supported by the intensive site usage close to houses, agricultural fields and human trails in villages. Conclusions: Our results indicate shifts in habitat selection and intensive site usage by mesocarnivores in the human-modified habitat. In future, this suggests the possibility of conflict and disease spread affecting both the people and wildlife. Therefore, this study highlights the requisite to test the wildlife responses to rapidly growing human expansions in modified habitats to understand the extent of impact. The management strategies need to have an integrated focus for further expansions of modified habitat and garbage disposal strategies, especially in the human-wildlife interface area.
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Affiliation(s)
| | - A. Cole Burton
- Faculty of Forestry, University of British Columbia, Vancouver, Canada
| | | | - Ramesh Krishnamurthy
- Wildlife Institute of India, Dehradun, Uttarakhand, India,Faculty of Forestry, University of British Columbia, Vancouver, Canada
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Candler EM, Severud WJ, Beyer DE, Frawley B, Bump JK. Untrapped potential: Do bear hunter cameras accurately index nontarget species? CONSERVATION SCIENCE AND PRACTICE 2021. [DOI: 10.1111/csp2.570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Affiliation(s)
| | | | - Dean E. Beyer
- Michigan Department of Natural Resources Marquette Michigan USA
| | - Brian Frawley
- Michigan Department of Natural Resources Marquette Michigan USA
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Klauder KJ, Borg BL, Sivy KJ, Prugh LR. Gifts of an enemy: scavenging dynamics in the presence of wolves (Canis lupus). J Mammal 2021. [DOI: 10.1093/jmammal/gyab020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Carrion represents an important resource for carnivores. Examining competition for carrion in a risk–reward framework allows for a better understanding of how predator guilds compete for and benefit from carrion. We used trail camera data to compare wintertime carrion use and vigilance behavior of four carnivores in Denali National Park and Preserve. We found that carrion use was dominated by wolves (Canis lupus) and wolverines (Gulo gulo), followed by red foxes (Vulpes vulpes) and coyotes (Canis latrans). Wolves and wolverines were twice as likely to visit a carcass as foxes and coyotes, and their visits were longer and more numerous. Our results suggest scavenging animals reduced their risk exposure primarily by reducing their use of carrion, with some evidence of increased vigilance at busy sites. We found that carrion use and behavior at carcass sites were influenced by the mortality type of the carcass, the age of the carcass, and the long-term intensity of wolf use in the area. Our results also suggest that wolves are the “top scavenger,” and indicate that intraguild competition for carrion strongly affects which species benefit from carrion, with larger and more aggressive species dominating.
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Affiliation(s)
- Kaija J Klauder
- School of Environmental and Forest Sciences, University of Washington, College of the Environment, Box 352100, Seattle, WA 98195-2100, USA
| | - Bridget L Borg
- National Park Service, Denali National Park and Preserve, P.O. Box 9, Denali Park, AK 99755, USA
| | - Kelly J Sivy
- School of Environmental and Forest Sciences, University of Washington, College of the Environment, Box 352100, Seattle, WA 98195-2100, USA
| | - Laura R Prugh
- School of Environmental and Forest Sciences, University of Washington, College of the Environment, Box 352100, Seattle, WA 98195-2100, USA
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Allen ML, Elbroch LM, Wittmer HU. Scavenging by fishers in relation to season and other scavengers. Ecol Res 2021. [DOI: 10.1111/1440-1703.12198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Maximilian L. Allen
- Illinois Natural History Survey University of Illinois Champaign Illinois USA
| | | | - Heiko U. Wittmer
- School of Biological Sciences, Victoria University of Wellington Wellington New Zealand
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Barry JM, Elbroch LM, Aiello-Lammens ME, Sarno RJ, Seelye L, Kusler A, Quigley HB, Grigione MM. Pumas as ecosystem engineers: ungulate carcasses support beetle assemblages in the Greater Yellowstone Ecosystem. Oecologia 2018; 189:577-586. [DOI: 10.1007/s00442-018-4315-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2018] [Accepted: 11/22/2018] [Indexed: 11/30/2022]
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