According to UNC Chapel Hill researchers who just crunched 10 years’ worth of data, climate change is throwing bird migration patterns just a tiny bit off-kilter — and that small disruption could have major effects on the health of bird populations.

Allen Hurlbert and Zhongfei Liang used more than 48 million observations from amateur birdwatchers to conclude that every 1.8-degree rise in temperature makes birds reach their migration milestones 0.8 days earlier on average (though much more for some species in some locations).

That’s less than 11 hours per degree, so who gives a titmouse’s mouse tit? Well, birds do, or would if they had brains big enough to contain a large-scale self-preservation instinct. Says Hurlbert:

Timing of bird migration is something critical for the overall health of bird species. They have to time it right so they can balance arriving on breeding grounds after there’s no longer a risk of severe winter conditions. If they get it wrong, they may die or may not produce as many young. A change in migration could begin to contribute to population decline, putting many species at risk for extinction.

So small changes in climate can lead to small changes in migration patterns which can have dire effects. It’s like the butterfly effect, only with no Ashton Kutcher and more birds going extinct. Which sounds like a wash, frankly.

(By Jess Zimmerman*, Grist.org / Countercurrents.org, 04/03/2012)

* Jess Zimmerman is the editor of Grist List.