Wildlife Response to Climate Change was Underestimated: Birds Migrate North

Climate change is impacting our globe as temperatures change and as species adapt. Now, though, scientists have revealed that the wildlife response to climate change is likely underestimated, and that the side effects may be much more far-reaching than previously thought.

Most previous studies have actually looked at species either shifting northward, or species shifting to a higher elevation. Rarely have studies examined both. That's why scientists decided to take a closer look at the phenomenon.

The researchers analyzed thousands of breeding bird surveys sent in by citizen scientists across the western United States and Canada over the past 35 years. This allowed them to see that most of the 40 songbird species studied shifted either northward or toward higher elevations in response to climate change-but didn't necessarily do both.

"In research on the effects of climate change, studies have shown birds and other organisms shifting north in latitude and others show that species are moving up in elevation, but we're not aware of any others that have looked at both simultaneously," said David King, one of the researchers, in a news release.

So what did the scientists find? It turns out that if you only look at latitude or elevation, you might interpret the lack of latitude shift as a lack of response. Yet it turns out that since birds are using both behaviors, there's a far greater response than previously recorded. It's therefore important to study both behaviors-shifting in both elevation and latitude-when conducting future studies.

That's not all that the researchers found, though. They also discovered that there were common, species-level traits that allowed them to hypothesize how species would respond to climate change in the future. More specifically, clutch size could be used as a marker for reproductive strategy and diet breadth could be a marker of a "generalist" species that is more flexible in food requirements.

"Generally speaking, birds with smaller clutch sizes showed greater shifts in latitude, but greater clutch size showed more shift in elevation," said King in a news release. "A more satisfying marker is the diet breadth, where we found birds with narrower diet breadth shifted farther up in latitude and elevation than birds with wider diet breadths, which is what we expected to see."

The findings were published in the journal Global Ecology and Biogeography.