Environmental sorting of vertebrate faunas: Is guild-level locomotor and dietary ecomorphology an indicator of paleoenvironment?

Indiana University, Bloomington IN

Investigators

Abstract

Environmental sorting of vertebrate faunas: Is guild-level locomotor and dietary ecomorphology an indicator of paleoenvironment? P. David Polly How do communities and species respond to environmental change? This question is important to conservation ecologists, biologists and paleontologists because the answers help understand what principles influence which species are found together in a community, how those species and their community will respond to changing climates and environments, and how we can better determine past climates and environments from assemblages of fossils in the geological record. This project will focus on how climatic and environmental parameters in North America are associated with the average locomotion and diet in terrestrial carnivores from two major biological groups, the mammalian Carnivora and snakes, each of which have their individual physiological and locomotor specializations, but both of which function ecologically as high-trophic level carnivores in the same communities. The project will study how two properties of the species coexisting in communities ? locomotion and diet ? are associated with climate and environment on a continental scale. We expect that species within a community will each be specialized for their own niches, but at the same time we expect that the large-scale climate and environment in a local area will restrict the range of differentiation that is possible within a community (all species living in an arctic tundra community, for example, must share specializations that allow them to live in that environment). Our goal is to determine the extent to which climate and environment are associated with the geographic distribution of locomotor and dietary specializations to assess the possibility of inferring past local terrestrial climates and environment from fossil communities using these systems. Our approach is quantitative and geographically comprehensive. From museum collections, we will take measurements of limbs, bodies, and dentitions of carnivorans and snakes from across North America, with the goal of obtaining a sample of 20 or more individuals for every North American species in these two groups and of obtaining samples of 10 or more across the entire geographic range of selected widespread species. We will also measure limbs and dentitions from Pleistocene carnivorans in order to apply our results to late Quaternary paleoenvironment reconstruction. These measurements will be assembled using Geographic Information System (GIS) methods to map the community-level patterns in locomotion and diet across the whole of North America to study how they are associated with climatic parameters and we will reconstruct Pleistocene climate and environment from this association and test that reconstruction against climate models based on other lines of evidence.