Climate Change Could Devastate Small Mammal Species

They say that history repeats itself, but usually it doesn't take nearly 13,000 years to happen. A study recently published in the journal Nature reveals some troubling similarities between current warming trends and the climate change that followed the Ice Age and contributed to significant loss of small mammal populations.

For the study, a team of scientists from Stanford University conducted cave excavation experiments in California's Shasta County, and found that the diversity in small animal populations following this period declined at least thirty percent.

According to fossils dug up in the caves, the report states, gophers and mountain beavers were as common as deer mice before temperatures rose 7-12 degrees Fahrenheit after the Ice Age. But while those species survived the shift, says Jessica Blois, a former Stanford graduate student who co-authored the study, they "have moved away to higher elevations or to cooler and wetter climates."

And scientists say we can expect a similar shock to mammal species if the climate shifts as much as scientists expect it will over the next decades. "It's the warming in the past that disrupted the diversity of those animal communities, and I'll expect that to happen again as the world's climate continues to warm," said Blois.

To some, it's difficult to imagine that small mammals — mice, gophers, beavers — would be in danger of extinction if the climate warmed just a few degrees. After all, each of the species mentioned above survived the Ice Age shift. But Blois says that oversimplifies the problem. "Even though all of the species survived, small mammal communities as a whole lost a substantial amount of diversity, which may make them less resilient to future change," she said. Elizabeth Hadley, a Stanford Professor who co-authored the study added that the temperature change the small mammal community is about to experience "is bigger than anything it has seen in the last million years."

So unless the global community takes collective action to stem the tide of climate change, it's clear that the next wave of climate change will have a drastic impact on smaller animals incapable of adapting to new temperatures. What remains unclear is whether larger mammals and humans will be safe bystanders of of that problem, or if the current climate change will also harm diversity of the human species.

Photo credit: Dane Low