Chimney swifts decline 95 percent in Canada between 1968 and 2005. After studying a six-foot deep pile of swift guano in a now-capped chimney on the campus of Queen’s University in Kingston, Ontario, researchers believe that DDTs impact on the beetle population played an important role in the swifts’ decline.

Studying the hard remains of insects in the pile, they found that the birds switched from a diet rich in beetles to one where true bugs (which include cicadas and stink bugs) were dominant.The researchers believe the switch from the energy-rich beetles to the less caloric true bugs was the worst kind of crash diet.

Read the news brief in ScienceNow.
Read the paper in Proceedings of the Royal Society B. (Open access.)

Photo courtesy of the National Park Service