1. Ornithology is a branch of zoology that studies birds. It studies different species of birds, their size, shape, colour, behaviour, habitat, reproduction and other aspects.

2. Ornithologists use a variety of methods to collect information about birds, such as field surveys, bird watching, studying bird behavior, and studying fossils.

Agni Neerja disease is caused by the Yellow Vein Mosaic Virus (YUMA). It is not usually sap transmissible, but it has been transmitted by grafting under experimental conditions.