Pumas as ecosystem engineers: ungulate carcasses support beetle assemblages in the Greater Yellowstone Ecosystem
Ecosystem engineers create physical changes in abiotic and biotic material, and through this process control the availability of resources for other species. Predators that abandon large portions of their prey may be ecosystem engineers that create habitat for carrion-dependent invertebrates that utilize carcasses during critical life-history periods. Between 04-May-2016 and 04-Oct-2016, we sampled beetle assemblages at 18 carcasses of prey killed by pumas and matching control sites in the southern Greater Yellowstone Ecosystem, USA, to measure the extent to which beetle families utilized these carcass “habitats”. We used generalized linear-mixed models and linear-mixed effect models to examine changes in beetle abundance, species richness, and Simpson’s Index of Diversity. We estimated kill rates and carrion production rates for individual pumas to better assess the impact of pumas on invertebrate communities. We collected 24,209 beetles representing 215 species. We identified eight beetle families that had significantly higher abundance at carcasses than control sites. Carcasses had a statistically large to very large effect (determined using Cohen’s d) on beetle abundance, richness, and diversity for the initial 8 weeks of sampling. Our research revealed strong effects of an ecosystem engineer on beetle assemblages while highlighting the potential role of apex predators in creating and modifying physical habitats for carrion-dependent species. This suggests that there may be consequences for invertebrate communities where apex predators exist at reduced numbers or have been eradicated. The ecological role of invertebrates is often overlooked, yet they are essential taxa that provide critical ecological services upon which we depend.
KeywordsBiodiversity Carrion Invertebrates Pumas Scavenging
We thank the Summerlee Foundation, Pace University, Hofstra University, Charles Engelhard Foundation, Eugene V. & Clare E. Thaw Charitable Trust, National Geographic Society (Grant C236-13), Connemara Fund, Tapeats Foundation, Community Foundation of Jackson Hole, Hogan Films, Ecotour Adventures, Mr. and Mrs. Folger, L. Westbrook, The Scully family, Mr. and Mrs. Haberfeld, Mr. and Mrs. Robertson, Mr. and Mrs. Heskett, Mr. and Mrs. Burgesses, D. Bainbridge, T. Thomas, and A. Smith for financial support of the project. We thank M. Ivie for his assistance to beetle identification. We also thank M. Peziol, C. O’Malley, A. Kusler, J. Williams, B. Smith and S. Smith for contributions to fieldwork. We are grateful for the feedback from the handling editor, two anonymous reviewers, and R. Brandl, Editor in Chief, Terrestrial Invertebrate.
Author contribution statement
JMB and LME conceived and designed the experiment. JMB and LME conducted the field work. JMB and MEAL conceived and performed statistical analyses. LS and AK conducted laboratory work on the beetle dataset. JMB and LME wrote the manuscript, with constructive feedback and additions from all authors. HBQ, MMG, and RJS provided institutional support for the work and graduate student training.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
All procedures performed in this study involving animals were in accordance with the ethical standards of the American Society of Mammals and were approved by two independent Institutional Animal Care and Use Committees (IACUC): the Jackson IACUC (Protocol 027-10EGDBS-060210) and National Park Service IACUC (IMR_GRTE_Elbroch_Cougar_2013-2015).
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