The Birds of Appa Lake

Hollow bones, modification of forelimbs, high temperature, presence of air sacs, presence of enormously powerful muscles, modification of jaws into beaks, modification of digestive system, stream lined body, absence of urinary bladder and absence of right ovary makes the body light and adapted for aerial life. There are about 1100 species of Bats present in the world. And around 110 species of bats are present in India. They are the only mammals with true flight, and this is mainly responsible for their worldwide distribution. Their organs of flight are the lateral extensions of the skin, the patagia supported by the fore-limbs and their greatly elongated digits, except the first. The patagia may include the hind-limbs and tail also in them. The hind-limbs are relatively short and weak with the knees turned backwards like the elbows. This makes the bats helpless on ground. All the five digits of the hind-limb and the first two digits of the fore-limb bear claws. All the bones are slender to reduce the body weight. The senses of touch and hearing are remarkably developed. Though the bats have eyes and see well, they guide themselves during flight by the principle of radar. They produce supersonic sounds, which are thrown back from the objects in the way and are perceived by the ears. The penis contains a bone in it. Usually there are only two mammae, which lie on the thorax. They produce only one or sometimes two young ones at birth. They are nocturnal animals, and spend the day hanging head downwards from the various objects by the claws of one or both the feet. The order Chiroptera is divided into 2 suborders : Microchiropters that includes the small bats and Megachiroptera that includes the large bats or flying foxes.

Description: the adult bird is 55–65 cm long with an 88–106 cm wingspan, and weighs 350–550g. Its plumage is normally white, although there are dark forms with largely bluish-grey plumage. In the breeding season, the adult has two long plumes on the nape that form a crest. These plumes are about 15 cm and are pointed and very narrow. There are similar feathers on the breast, but the barbs are more widely spread. It has several elongated scapular feathers that have long loose barbs which are 20cm long.

In the winter the plumage remains unchanged but the scapulars are shorter and more normal in appearance. The bill is long and slender and the lores are black. There is an area of greenish-grey bare skin at the base of the lower mandible and around the eye which has a yellow iris. The legs are black and the feet yellow. Juveniles are similar to non-breeding adults but have greenish-black legs and duller yellow feet, and may have a certain proportion of grayish or brownish feathers.

Distribution and habitat: these are found in southern Europe, the Middle East, much of Africa and southern Asia. Northern European populations are migratory, mostly travelling to Africa although some remain in southern Europe, while some Asian populations migrate to the Philippines. The little egret's habitat varies widely, and includes the shores of lakes, rivers, canals, ponds, lagoons, marshes and flooded land, the bird preferring open locations to dense cover. On the coast it inhabits mangrove areas, swamps, mudflats, sandy beaches and reefs.

Behavior: little egrets are social birds and are often seen in small groups. Nevertheless, individual birds do not tolerate other birds coming too close to their chosen feeding site, though this depends on the abundance of prey. They use different methods to procure their food. They stalk their prey in shallow water, often running with raised wings or shuffling their feet to disturb small fish, or may stand still and wait to ambush prey. On land they walk or run while chasing their prey, feed on creatures disturbed by grazing livestock and ticks on the livestock, and even scavenge.

Their diet is mainly fish, but amphibians, small reptiles, mammals and birds are also eaten, as well as crustaceans, mollusks, insects, spiders and worms. Little egrets nest in colonies, often with other wading birds, build their nest in the trees and lays three to five eggs. The eggs are oval pale non glassy blue green in color. The eggs are incubated 21 to 25 days both by male and female. After 45 days the young ones are able to fly.

Conservation status: the International Union for Conservation of Nature states that they are "least concern". In the Appa lake around 100-150 birds can be seen sitting in trees.