By Mary Katherine Ray, Rio Grande Chapter Wildlife chair
On Sept. 9, an early cold front stormed into New Mexico from the north, bringing record cold temperatures and freezing rain. Worse, it appears that this weather event played a role in the mass die-off of migratory birds that happened at the same time. Thousands of bird remains have been found in the Southwest by scientists and the public alike. Many have been sent for necropsies to determine why they died.
We won’t get the results for a while, but preliminary study indicates these birds weighed 1/3 less than they should have. Birds need the fuel from their fat stores to make their long migratory journeys and to keep warm. Almost all of the bird remains belonged to species that depend on insects for their food like swallows and warblers. The cold would have made the insects difficult to find. In essence, we may learn that starvation was the root cause.
Happily, after the cold front, these two birds (an adult male Wilson’s Warbler, left, and a juvenile Violet-Green Swallow) were photographed still alive and still on their journey south. They’d stopped at a spring in the San Mateo Mountains in Socorro County both for water and flying insects which had re-emerged.
Featured photo from NBC News