The flight of the Snail Kite is slow but buoyant, with several deep wingbeats alternating with glides during which the wings are cupped. The wings appear bowed during flight. When foraging, the kite makes tight, graceful turns on its broad, rounded wings. The foraging flight is described below. During midday kites often soar, ascending high enough to be invisible from the ground. The species is social with others of its kind and is tamish around people.
The Snail Kite hunts from an elevated perch, spotting a snail and going after it, or by coursing low over the wetland with more or less constant slow flapping of its bowed wings, scanning the water's surface and below for the presence of a snail. When about to strike, it dangles one or both legs. It seizes an apple snail near the water's surface and gets, at most, only its legs and thighs wet doing so. It may transfer the snail from foot to beak before settling on a perch to extract the snail body from the shell. In Florida, perch hunting is mostly done by young kites. Kites hunt throughout the day. When snails are plentiful kites spend very little time searching for them. A 78 percent capture rate was reported in one study. Droughts cause snails to bury themselves in the mud of the marsh bottom for the duration. Capture rates under such circumstances drop severely. The passage of a cold front with wind disturbing the surface of the water and decreased activity among cold snails also cause kites to have much difficulty finding snails. To detach the snail from its shell the kite must position the shell correctly, insert the tip of its beak between operculum and shell, and twist off the operculum which acts as a door guarding the snail. The bird inserts its beak into the curve of the shell and severs the muscle holding in the snail. These actions require much practice before young birds become proficient. The kite extracts the snail and tears it up or swallows it whole. The snail's yolk sac and sometimes its digestive tract are discarded. In Florida, the average time to extract and eat a snail was 90 seconds.
The Snail Kite rarely defends a feeding area. Its food is probably quite widespread and cannot be defended under normal circumstances. One unusual case occurred where several nonbreeding kites each vigorously defended their own small feeding territories along a canal where apple snails were superabundant. As the species Latin name suggests, the Snail Kite is quite social, roosting communally in numbers and also nesting in colonies, in Florida numbering from five to 20 nests. In one study, 71 nests ranged from six to 287 yards (5.5 to 261 meters) from nearest neighbors, the average distance being about 84 yards (76 meters). Solitary nesting also occurs. A small territory surrounding the nest about four yards (3.6 meters) in each direction (sometimes as large as 30 yards) is defended by the nesting parents. After fledging, young from several nests may form a large group which feeds in the same general area and roosts together.
The Snail Kite is fairly unaggressive. Many marsh birds show little fearful response to its presence. However, a nesting adult kite will dive at a passing potential predator, such as a Northern Harrier.
Several displays are known. On rare occasions early in the breeding season, groups of kites have been reported circling and darting at one another, grappling and somersaulting in mid-air. This may represent an early stage of pair formation. The male may sky-dance, rising up and then closing his wings to dive steeply two to four yards (1.8 to 3.6 meters), before opening his wings and rising again to repeat the movement. He often carries a stick. He may dive upon a potential mate, or intruders near his future nest site. He may call either the "ka-ka-ka-" vocalization or the "ker-wuck" call during this display. The male may also give deep wing-beats, flying with very accentuated downward wing beats, the wing tips reaching well below the body. He may direct this display toward a potential mate near his future nest site or intruders in the same area. Other displays include a shallow 'pendulum' dive with some wing flapping, followed by a tight turn, and the whole process repeated, and mutual soaring of two prospective mates flying close together while diving and rolling.
The male may begin to construct a nest or defend a nest site before securing a mate. After attracting a female, the male captures a snail and feeds it to her, landing atop a potential nest site with the snail and the female flying to him. The male initiates copulation. During copulation he gives a rattling, gurgling call. Often after copulation the male leaves to find nesting material. The male finds the bulk (80 percent) of the nest material and also provisions the female as well, bringing her 83 percent of her food. He also chases away other kites or potential predators.
The oldest bird in the wild lived 13 years. The average adult life span may be only six years. Likely the main cause of adult mortality is starvation due to drought. Snail Kites are tame and often allow humans to approach them closely. Illegal shooting has caused deaths in Florida during waterfowl hunting season and when birds disperse over large areas because of drought. Nestlings have suffered injury and mortality because of wounds caused by gnawing dermestid beetles. Nests are also plundered by raccoons, Boat-tailed Grackles, Northern Harriers, cottonmouths, and rat snakes. Adult kites may also desert nests when the passage of cold fronts cools shallow marsh waters, causing a decrease in snail activity and a corresponding lack of food for the kites.
ADAPTATIONS
The Snail Kite is well adapted to its environment. Physically, its narrow, sharply decurved bill is superbly shaped to remove the protective operculum (shield or door) of the apple snail, and to plunge inside the shell to sever the columellar muscle attaching the snail to its shell. It is also well adapted to the irregular fluctuations in water levels which dramatically affect its food supply and nesting success. It meets the challenges of irregular drought/high water cycles in a number of ways. Firstly, Snail Kites are nomadic in times of drought, searching for areas where snails are still accessible. When food is abundant a nesting pair will raise young to the point where one adult can feed the nestlings her or himself. The other adult deserts the nest to renest with a new mate immediately. In addition, young Snail Kites are capable of successfully breeding when less than one year old. Finally, breeding can take place at any month in the year. Working alone or in combination, these adaptive features allow Snail Kites to propagate well in good years, and survive by dispersing in bad ones.
#Identify this bird of prey.;question\Q02\Q02.wav
P3ImageView
SNKI\091604.bmp
SNKI\091604b.bmp
Feeds almost exclusively on snails
²ÆÇÇÇÇÇ #Identify this bird of prey.;question\Q02\Q02.wav
