Major Causes in Declining Population of House Sparrow in Karachi

House Sparrow (Passer domesticus) belongs to the family Passeridae.It is found in most parts of the world. As small bird, its length is 16 cm (6.3 in) and weight is 24-39.5 g (0.85-1.39 oz). Female and young birds are pale in color brown and grey, whereas males have brighter black, white, and brown markings. House Sparrows live in urban or rural settings. Though found in widely varied habitats and climates. It feeds mostly on the seeds of grains and weeds, but it is an opportunistic eater and commonly eats insects and many other foods. Its predators include domestic cats, hawks, owls, and many other predatory birds and mammals. There are variations in house Sparrow vocalizations. It transcribed as chirrup, tschilp, or philip, this note is made as a contact call by flocking or resting birds, or by males to proclaim nest ownership and invite pairing. In the breeding season the male gives this call repetitively, with emphasis and speed but not much rhythm, forming what is described either as a song or an "ecstatic call", similar to a song.. House Sparrow is a social bird. It is gregarious at all seasons when feeding, often forming flocks with other types of bird.