Latin name:Apus affinis subfurcatus
Vietnamese Name:Yến cằm trắng
Family:Apodidae
Order:Apodiformes
Class (Group):

Adult Characteristics:

A black spot is located in front of the eye, with a narrow pale gray band above. The head, back, wings, and tail are pale brownish-black, except for a pale brown band on the forehead. The wing feathers have very thin pale edges. A wide white band runs across the flanks, with the body feathers usually having dark brown streaks. The chin and throat are white, and the body feathers are usually dark-colored. The rest of the belly is pale brownish-black.

Eyes are dark black. The bill is black.

The legs are pinkish-brown or reddish-black.

Measurements:

  • Wing: 130 – 112 mm
  • Tail: 41 – 47 mm
  • Tarsus (Leg): 9 – 10 mm
  • Bill: 6 mm

Distribution:

This swift species is distributed in Assam, Bengal, Burma, Southern China, Thailand, Indochina, Malaysia, Sumatra, and Borneo.

Vietnam:

This species nests in rock caves in Lai Chau, Bac Kan, Ninh Thuan, and Southern Vietnam.