[Source: Wekipedia – Birds (class Aves) are feathered, winged, bipedal, endothermic (warm-blooded), egg-laying, vertebrate animals.]
But to make them precisely distinguishable from other animals they can be described as “bipedal animals with feathers”. Science apart, birds are colorful winged creatures with the fascinating ability to fly, to sing and to build their own nest.
Importance of birds
Biological Control – feeding on harmful insects, is a natural way of pest control. Predator birds keeps control on rat (rodent) population. Birds consumes weed seeds.
Spreading agents – birds feeding on nector pollinates many species of plants. Spreads seeds (seeds that passes undigested through their body as waste) and introduce plants to new areas.
Scavengers – birds like vultures, Kites and Crows effectively cleans the carcasses in and around our cities or villages and helps in preventing diseases and air pollution.
Environmetal indicators – birds disappearing from an area indicates decreasing health of that ecosystem. Bird types available in an area shows biological type of that area (eg. presence of nector eating birds indicates prevalence of flower plants in that area).
Apart from these obvious reasons there are more to birds that calls for their conservation.