Basically a flying cigar, this bird spends most of its life in the air, only landing to roost in chimneys. They are incapable of perching in trees like other birds but have adapted to clinging to the insides of chimneys where they spend the night.
Before European settlement brought chimneys to North America, Chimney Swifts nested in caves, cliff faces, and hollow trees. With the arrival of structures with fireplaces . . . their population exploded but is now declining as chimneys now have caps or screens.
A long distance migrant, Chimney Swifts winter in South America and return to the Eastern USA each spring, traveling through Mexico and Texas.
I saw my first Chimney Swift of the year this afternoon over a Sanford Sewage Treatment plant.