This study is an extraordinary example of fossils being used to show the impacts of climate and human disturbance on an ecosystem in Utah. Interestingly, the study has found that the small mammal community could cope with changes in climate but not with changes in land-cover in the 1800s. We see this trend continuing with recent reports that we are entering a sixth global mass extinction event as a result of human overpopulation:
A collection of fossilized owl pellets in Utah suggests that when Earth went through a period of rapid warming about 13,000 years ago, the small mammal community was stable and resilient, even as individual species changed along with the habitat and landscape. By contrast, human-caused changes to the environment since the late 1800s have caused an enormous drop in biomass and "energy flow" in this same community, researchers reported today in Proceedings of the National Academy of Sciences.