New study shows differences in mammal responses to climate change
If you were a shrew snuffling around a North American forest, you would be 27 times less likely to respond to climate change than if you were a moose grazing nearby.
That is just one of the findings of a new University of Colorado Boulder assessment led by Assistant Professor Christy McCain that looked at more than 1,000 different scientific studies on North American mammal responses to human-caused climate change. The CU-Boulder team eventually selected 140 scientific papers containing population responses from 73 North American mammal species for their analysis.
The studies assessed by the team examined seven different responses to climate change by individual mammal species: local extinctions of species known as extirpations, range contractions, range shifts, changes in abundance, seasonal responses, body size and genetic diversity. The researchers used statistical models to uncover whether the responses of the 73 mammals to a changing climate were related to aspects of their physiology and behavior or the location of the study population.
The analysis showed only 52 percent of the mammal species responded as expected to climate change, while 7 percent responded the opposite of expectations and the remaining 41 percent had no detectable response. The two main traits tied to climate change responses in the CU-Boulder study were large mammal body size and restricted times during a 24-hour day when particular mammal species are active, she said.
A paper on the study by McCain and former CU-Boulder postdoctoral fellow Sarah King was published online Jan. 22 in the journal Global Change Biology. The National Science Foundation funded the study. King is currently a research associate at Colorado State University.
While body size was by far the best predictor for response to climate change -- almost all of the largest mammals responded negatively -- the new study also showed that mammals active only during the day or only at night were twice as likely to respond to climate change as mammals that had flexible activity times, she said.
"This is the first time anyone has identified specific traits that tell us which mammals are responding to climate change and which are not," said McCain of CU-Boulder's ecology and evolutionary biology department.
McCain said she and King were surprised by some of the findings. "Overall the study suggests our large, charismatic fauna -- animals like foxes, elk, reindeer and bighorn sheep -- may be at more risk from climate change," she said. "The thinking that all animals will respond similarly and uniformly to temperature change is clearly not the case."
Continue reading at University of Colorado Boulder.
Elk image via Shutterstock.