DDT blamed in chimney swift decline

In April, chimney swifts will return, but every year there seems to be fewer. One reason that chimney swift numbers are down is that we cap chimneys to keep them out. No one wants a chimney full of birds, nests and droppings. And no one wants live birds flying around the living room.

A recent study in Canada recently revealed another factor that has played a role in the decline of chimney swifts. Chris Grooms, a research technician at Queen's University, discovered an abandoned five-story chimney in a campus building that contained a pile of swift poop more than 6 feet deep.