Question

why have number of some birds and animals reduced

Answer 1

The reasons are deforestation, pollution, killing, over exploitation etc. The most important among them is deforestation or destruction of their natural habitat because it will affect the species (flora and fauna) of complete area and not only the few organisms.

Hunting and habitat loss are the two main reasons behind the decline. "Collision" with electricity lines, according to the study, is a "prime current threat" to birds.

Answered by GauthMath.