PS 16-157 - CANCELLED - Life after death – does carcass biodiversity scale with carcass body size?

Background/Question/Methods

Mammals play a large role in the ecosystems where some, especially large-bodied mammals, act as ecosystem engineers. Mammals physically alter their environment through changes in nutrient cycling and vegetation alteration; these impacts extend even after death. Mammal carcasses, particularly those of large body mass, act as a temporary island of dense nutrients that support other organisms, including other mammal species, for an extended period. As biological diversity declines and many large-bodied mammals are threatened globally, questions arise. Does the available biomass (i.e., body size) of the carcass change its role? How is the carcass exploited by other members of the ecosystem? This research seeks to understand the role of mammal body size during carcass decomposition and its role in supporting living mammal diversity. The research project proposed here will test the hypothesis that mammal carcass size is positively correlated with the number of mammal species and mammal abundance associated with that carcass.

Results/Conclusions

Using a camera-trap monitoring system in a forested, sparsely populated site in the Arkansas River Valley, we measured the biodiversity associated with mammal carcasses of small and medium size. A medium mammal carcass (8.5 kilograms) attracted 10 mammal species, with some up to 27 kilograms, over a period of two weeks. A second medium-sized mammal carcass (5.5 kilograms) attracted 7 species over a period of two weeks. All mammals exploited the carcass in some manner, either by scavenging the carcass or feeding off the insects that also consume the carcass. Preliminary information from smaller carcasses ( < 1kg) suggests that variation in mammal carcass size impacts the observed biodiversity. When compared to the controlled observations at the same region, when no carcasses were present, there is an increase in the diversity and abundance of species observed. This demonstrates that living mammals regularly exploit mammal carcasses for resources and suggests that the larger a carcass is, the more it may serve as an important resource to the nutrient cycling of an ecosystem. These results can be used to understand the impacts of biodiversity loss, specifically the loss of large-bodied mammals.