Silberbürzelsegler Rhaphidura leucopygialis

Small, bullet-shaped swift with rather broad-based wings. Dark (glossy blue in optimal light) with extensive silvery rump patch. Named for thin protrusions from the tail, only sometimes visible at close range. Forages aerially over forest and edge habitat, often near water, sometimes in large numbers and among other swift species. Gives a rapid-fire, chattering trill.