RAPTORS OF SRI LANKA

Photographs & Text by – Dhilip De Alwis – Naturalist at ‘The Other Corner’ (www.tocsrilanka.com) – Habarana – Sri Lanka.

A raptor is a special type of bird which captures live prey. The word “raptor” means “to seize or grasp” in Latin. Raptors use their powerful, sharp talons to capture their prey and to defend themselves. Several bird species are considered raptors. Eagles, hawks, kites, falcons, and owls are all considered raptors. Vultures are often considered raptors as well, though they eat carrion and are more closely related to storks.

Raptors have acute hearing and vision, which is estimated to be eight to ten times that of humans. The ears of a raptor are an important tool in locating prey. Their ears are located behind their eyes on the edge of the facial disk and are concealed by feathers. They are vertically offset (one is higher and one is lower) to help locate the source of a sound more precisely. Raptors have a keen sense of vision, which helps them locate and track their prey. A raptor’s eyes are very large in relation to the size of their skull. But raptors are not able to move their eyes around like humans can. Instead they have extra bones in their neck which allow them to move their whole head around. Some raptors, like owls, can rotate their heads 270 degrees!

With the exception of his immediate successor, Nissankamalla I, all other monarchs of Polonnaruwa were slightly weak-willed and rather prone to picking fights within their own court. They also went on to form more intimate matrimonial alliances with stronger South Indian kingdoms until these matrimonial links superseded the local royal lineage and gave rise to the Kalinga invasion by King Kalinga Magha in 1214 and the eventual passing of power into the hands of a Pandyan King following the Arya Chakrawarthi invasion of Sri Lanka in 1284. The capital was then moved to Dambadeniya.

Though it’s difficult to estimate the lifespan of raptors in the wild, many birds can live up to five or six years. However, most birds do not make it past their first winter. This is usually due to predation or starvation. If a bird makes it past their first winter, then locating food becomes their biggest concern. Most raptors have varied diets, which can include: small mammals (such as mice and rabbits), reptiles (like snakes, lizards and frogs), large insects (grasshoppers and cicadas for instance) and other birds.

Though owls are raptors, they have some interesting features that set them apart from other raptors. First of all, you are far more likely to see a hawk or a falcon than you are an owl. This is because owls are usually nocturnal (meaning they hunt at night), while other raptors are diurnal (meaning they hunt during the day.) Owls may seem “fluffier” than other raptors. This is because owls have special feathers that make their flight virtually silent. Owls also appear more bulky and less streamlined than most raptors. This is because they are built for short and strong bursts of flight; rather than the soaring flight of hawks or eagles. This bulky build also helps owls carry larger prey than many other raptors. Hawks can carry prey that weighs about half their weight. But owls can carry prey that weighs as much as two to three times their body weight!

Many species of birds may be considered partly or exclusively predatory. However, in ornithology, the term "bird of prey" applies only to birds of the families listed below. Taken literally, the term "bird of prey" has a wide meaning that includes many birds that hunt and feed on animals and also birds that eat very small insects. In ornithology, the definition for "bird of prey" has a narrower meaning: birds that have very good eyesight for finding food, strong feet for holding food, and a strong curved beak for tearing flesh. Most birds of prey also have strong curved talons for catching or killing prey. An example of this difference in definition, the narrower definition excludes storks and gulls, which can eat quite large fish, partly because these birds catch and kill prey entirely with their beaks, and similarly bird-eating skuas, fish-eating penguins, and vertebrate-eating kookaburras are excluded. Birds of prey generally prey on vertebrates, which are usually quite large relative to the size of the bird. Most also eat carrion, at least occasionally, and vultures and condors eat carrion as their main food source.

All Raptors have a hooked beak, excellent eyesight, sharp talons, and strong legs and feet. A raptor's beak is one feature used to set them apart from other birds. All raptors have the same beak design, curved at the tip with sharp cutting edges to tear apart prey that will easily fit into the mouth.

The beaks have evolved over time based on the type of prey eaten. For example, the American kestrel has a small beak for eating small prey, like mice and insects. Eagles have powerful, heavy beaks for tearing large pieces of meat, but snail kites have a highly specialized long, curved beak for probing inside snail shells.

Birds of prey have powerful leg and toe muscles that, when combined with their sharp talons, make their feet lethal weapons (see Sharp Feet Activity Sheet), perfectly designed to catch, hold, and carry prey. The length and size of a raptor’s toes, and the curvature and thickness of its talons are related to the type of prey it pursues.

In Sri Lanka there are 29 recorded specimens living in different geographical conditions. The latest survey which was carried out by the Birds of the South Asia, The Repley Guide, volume 1: Field Guide, Second Edition, Pamela C. Rasmussen, John C. Anderton. ,the “ LEGGE'S HAWK EAGLE” has been categorize as an endemic bird to Sri Lanka and Western Ghats. Common Kestrel, Amur Falcon, Oriental Hobby, Peregrine Falcon, Black-Winged kite, Black Kite, Brahminy Kite or Red Backed Sea Eagle, Osprey, White bellied sea Eagle, Grey Headed Fish Eagle, Eurasian Marsh Harrier, Pallid Harrier, Pied Harrier, Montague’s harrier, Jerdon’sBaza, Black Baza, Crested Goshawk, Shikra, Besra, Oriental Honey Buzzard, Himalayan Buzzard, Long Leged Buzzard, Crested Serpent Eagle, Black Eagle, Leges Hawk Eagle, Changeable or Crested Hawk Eagle, Rufous-Bellied Eagle, Booted Eagle, Bonelli’s Eagle the 29 species been recorded so far in the island. In this lot there are Endemics, Residents and Migrants been found in various geographical conditions in Sri Lanka.In addition to the above very rare record of under mentioned Vagratns had been spotted too. Lesser Kestrel, Red-Necked Falcon, Eurasian Hubby, Eurasian Sparrowhawk, Tawny Eagle. These Vagrants are not been recorded more often because of they are very rare migrators to Sri Lanka.

From 2014 December I was observing the behavior patterns of the White Bellied Sea Eagle & the Brahminy kite. They started their incubation in latter part of December 2014 and the chicks were out of the eggs by end of January 2015. When the chicks turned into juveniles parents were feeding them internally by taking turns and most of the time it was the male bird that finds food for the entire family. When you compare both the species the Brahminy juvenile learn their lessons faster than the White Bellied Sea Eagle. The Brahminy juveniles started hunting just after fourth month but also the parents birds did feed them by reducing the original amount of food which they use to bring. When comparing Brahminy Kites with the White Bellied Sea Eagles, White Bellied Sea Eagle fed their juveniles throughout the full six months (this time it went little longer by touching the seventh month). Now the parent birds of both species are getting ready for the next reproduction. Also other raptors are also getting ready for their reproduction Last but not least I must give my special thanks to “DulanRangaVidhanapathirana” for contributing certain very important information in this regard.

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