Natural History Wanderings

Yesterday I accompanied Rusty Scalf who is monitoring the Vaux’ Swifts who roost in an unused Chimney in Marin County. Between approximately Aug. 15 and Oct. 15 Vaux’s Swifts migrate to their wintering area from central Mexico south through Central America. This chimney has become a stopover spot on their way south.

It is not uncommon for these swifts to use chimneys to roost at night, and once a population of swifts locates an appropriate chimney, they often return year after year. Groups of roosting swifts can range in size from just a few individuals to as many as 35,000 in some larger smokestacks. Yesterday Rusty counted approximately 15,800 going into the chimney.

See a video of some of the action at  Video of Vaux’s Swifts flying into Chimney