Common Bulbul
Pycnonotus barbatus
The common bulbul is 18–20 cm (7.1–7.9 in) in length, with a long tail. The sexes are similar in plumage but the male is on average larger. It has a dark brown head and brown upperparts. The underparts are dull grey. The bill is fairly short and thin, with a slightly downwards curving upper mandible. The bill, legs, and feet are black and the eye is dark brown with a dark eye-ring, which is not readily visible. Subspecies P. b. dodsoni, P. b. spurius, P. b. tricolor and P. b. layardi have yellow undertail coverts. The call is a loud doctor-quick doctor-quick be-quick be-quick.
ID text from Wikipedia, CC BY-SA 4.0
Red-vented Bulbul
Pycnonotus cafer
The red-vented bulbul is easily identified by its short crest giving the head a squarish appearance. The body is dark brown with a scaly pattern while the head is darker or black. The rump is white while the vent is red. The bird is about 20 cm in length, with a long black tail, tipped in white. The Himalayan races have a more prominent crest and are more streaked on the underside. The race intermedius of the Western Himalayas has a black hood extending to the mid-breast.
ID text from Wikipedia, CC BY-SA 4.0
Where you might meet both
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