Yellow Warbler
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Yellow Warblers and Western Meadowlarks are two species of California birds that are nesting a week earlier than they did 70 to100 years ago, apparently in response to rising temperatures. Earlier nesting offsets about a two-degree temperature rise they would have experienced had they not accelerated nesting times. This study reveals broad-scale climate change adaptation not previously recorded in birds. The discovery of this startling news is due in part to meticulous records kept by Joseph Grinnell in statewide surveys he led a century ago.
Grinnell’s 74,000 pages of field notes provided a unique baseline and set the stage for ornithologists at the University of California at Berkeley to repeat his surveys, some of which Grinnell conducted using a Model T, some by using mules. Survey data was collected on 202 species of nesting birds in California.