Silver-backed Needletail

Hirundapus cochinchinensis formosanus

Endemic Subspecies

The Silver-backed Needletail is a large (20 cm) swift with blackish brown wings, upper tail, breast and belly, white undertail coverts, a grayish throat and a whitish saddle on the back and rump.  The tail is short and squarish.  The Taiwan race formosanus was previously assigned as a subspecies of the White-throated Needletail H. caudacutus, but has recently been shown to be virtually identical to the nominate race of the Silver-backed Needletail (H. cochinchinensis cochinchinensis), and “clearly belongs to this species” (Handbook of Birds of the World Vol. 5).

Like other swifts, the Silver-backed Needletail feeds on flying insects, and is often seen in flocks over water, feeding on emerging insects.  It is commonly seen in mixed flocks with the Fork-tailed or Pacific Swift, Apus pacificus.   The Silver-backed Needletail is highly mobile, and remains in an area only if food is plentiful.  Little is known about the breeding and nesting habits of this species.

In Taiwan it is a common summer resident from lowlands to mid elevations, especially over forested areas near water.

References:  Handbook of Birds of the World Vol. 5; A Field Guide to the Birds of China (Mackinnon and Phillipps); 100 Common Birds of Taiwan (Wild Bird Society of Taipei)