Breeding

Breeding is reported from April-June on Trinidad (Belcher and Smooker 1936); in June in Suriname (Haverschmidt 1968); in February and in May in Colombia (Hilty and Brown 1986); and from September-November in central and eastern Brazil (Sick 1948, Carvalho 1962, Whitney 2007). Specimens in breeding condition were collected in Venezuela in April and August (Friedmann and Smith 1950).

Fork-tailed Palm-Swifts place the nest exclusively in palm trees; the most frequently used species is Mauritia flexuosa (Belcher and Snooker 1936, Sick 1948, Carvalho 1962), but other species are used as well, including non native palms such as Livistona chinensis (Carvalho 1962).

The nest is attached to a dead, dry, drooping palm frond, close to the trunk; it is affixed to the outer surface of the hanging frond (which, when the frond was alive and erect, would have been the inner surface) (Sick 1948). The nest "has the aspect of a disorderly, elongated clump of feathers", ca 13 long, with an entrance at the bottom. The nest is made primarily of bird feathers, with smaller amounts of plant "cotton" and held together with saliva (Sick 1948). The feathers making up the nest predominately are from pigeons and parrots (Belcher and Smooker 1936, Sick 1948, Carvalho 1962, Whitney 2007). These feathers are collected by the swifts in a remarkable act of aerial piracy: from a great height (100 m or more), the swift stoops down on a bird in flight, alighting on the bird's back and, with the bill, tugging loose a mouthful of feathers (Whitney 2007). Whitney (2007) observed palm-swifts stealing feathers from ca 50 species of birds, representing 21 families, and ranging in size from Turkey Vulture (Cathartes aura) to tyrant flycatchers (Tyrannidae) and thrushes (Turdus).

The clutch size is three (Sick 1948, Carvalho 1962).  The eggs are white and unmarked (Carvalho 1962). The dimensions of one egg were 10.0 x 15.5 mm (Sick 1993). The incubation period is 21 days (Carvalho 1962).