Spring Gets Out Of Sync

Author: Jane Kay, Chronicle Environment Writer

In the natural world, animals take cues about when to migrate and when to mate from the hours of daylight, the temperature and the amount of rain and snow. Here in the Applegate Valley, for example, every spring the yellow-and-black anise swallowtail emerges from its cocoon just as the wildflowers it feeds on bloom.

That's the way it's supposed to work: a natural synchronicity between seasons and species, born of evolution and adaptation. But now nature's timing is off.

After three decades of warming not seen in more than 1,000 years, spring arrives earlier around the world. As species shift their ranges toward the cooler poles or higher elevations, the season brings unexpected arrivals of migrating birds and mistimed hatchings of insects and flowerings of trees.

Read full story at San Fransico Chronicle.