He really wanted to get back "home" to Alabama . It took him about four months to make it to South America but only one to get back to Fur's sanctuary in Alabama. This is all very interesting .
They aren't in a hurry to head south since they don't have an actual home to go to in south America. They just sleep in trees down there. When they're coming back here, they've got to compete for a nesting spot.
Has anyone seen a pair nest in anything other than a man made structure? Do they use tree hollows or ???
There are very, very few documented cases of them living in natural cavities in the east. There's an occasional report of them nesting in a street light in various places. There's a different subspecies of Martin that lives on the west coast that still use quite a few natural cavities. They nest in the Saguaro cactuses in the desert regions of the SW, all the way up the west coast into Canada.