Mammals Alter Diets with Global Warming!

How did global warming (i.e., interglacial warming) affect mammalian communities?  It turns out that mammals changed their diets quiet dramatically in response to interglacial warming, during the Pleistocene.  The idea that the ecological niches were conserved over time, is not upheld.  Instead, interglacial warming resulted in: increased consumption of C4 resources by some animals, increased isotopic niche breadth of other animals, isotopic niche partitioning of closely related animals (e.g., lamas and peccaries), and changes in the behavioral ecology of other animals (e.g., deer and tapirs).  Additionally, interglacial warming contributed to decreased seasonality and increased aridity in Florida ~1.5 million years ago.  In summary, interglacial warming appears to have increased the abundance of C4 grasses and contributed to increased heterogeneity of environments and the resulting diets of ancient mammals.  While the Pleistocene mammals studied may have benefited from interglacial warming, modern mammalian communities may be unable to adapt to the current rapid rates of global warming. 

Climate change? Big mammals may be flexible - Discovery News / msNBC 
Ancient Mammals Not So Finicky - ScienceNOW Daily News  
Fossil Teeth Hint at Animal Adaptation to Global Warming - Wired Science