Tuesday, September 16, 2014

Shikra - Resident Breeder in Sri Lanka.

The shikra (Accipiter badius) is a small bird of prey in the family Accipitridae found widely distributed in Asia and Africa where it is also called the little banded goshawk. The African forms may represent a separate species but have usually been considered as subspecies of the shikra. The shikra is very similar in appearance to other sparrowhawk species including the Chinese goshawk and Eurasian sparrowhawk. They have a sharp two note call and have the typical flap and glide flight. Their calls are imitated by drongos and the common hawk-cuckoo resembles it in plumage.

The shikra is a small raptor (26–30 cm long) and like most other Accipiter hawks, this species has short rounded wings and a narrow and somewhat long tail. Adults are whitish on the underside with fine rufous bars while the upperparts are grey. The lower belly is less barred and the thighs are whitish. Males have a red iris while the females have a less red (yellowish orange) iris and brownish upperparts apart from heavier barring on the underparts. The females are slightly larger. The mesial stripe on the throat is dark but narrow. In flight the male seen from below shows a light wing lining (underwing coverts) and has blackish wing tips. When seen from above the tail bands are faintly marked on the lateral tail feathers and not as strongly marked as in the Eurasian sparrowhawk. The central tail feathers are unbanded and only have a dark terminal band. Juveniles have dark streaks and spots on the upper breast and the wing is narrowly barred while the tail has dark but narrow bands. A post juvenile transitional plumage is found with very strong barring on the contour feathers of the underside. The call is pee-wee, the first note being higher and the second being longer. In flight the calls are shorter and sharper kik-ki ... kik-ki. The Chinese sparrowhawk is somewhat similar in appearance but has swollen bright orange ceres and yellow legs with the wing tips entirely.

Several subspecies are recognized across its range and some of them may be treated as full species. It has been suggested, based on differences in morphology and calls, that the African forms do not belong to this species. Subspecies cenchroides (Severtzov) is larger and paler and found in Turkestan, Afghanistan and eastern Iran. The Indian population dussumieri is resident on the plains and lower hills (up to 1400 m in the Himalayas). The nominate form is found in Sri Lanka and has somewhat darker grey upperparts. The Burmese shikra A. b. poliopsis may represent a distinct species. The population on Car Nicobar Island, earlier treated as a subspecies butleri and that on Katchall Island, obsoletus are now treated as a sub-species within a full species, the Nicobar sparrowhawk (Accipiter butleri). The west African population A. b. sphenurus is migratory while the southern African A. b. polyzonoides is more nomadic in its movements. In Asia onlyA. b. cenchroides is migratory.

The shikra is found in a range of habitats including forests, farmland and urban areas. They are usually seen singly or in pairs. The flight is typical with flaps and glides. During the breeding season pairs will soar on thermals and stoop at each other. Their flight usually draws alarms among smaller birds and squirrels. They feed on rodents (including Meriones hurrianae), squirrels, small birds, small reptiles (mainly lizards but sometimes small snakes) and insects. Small birds usually dive through foliage to avoid a shikra and a Small Blue Kingfisher has been observed diving into water to escape. Babblers have been observed to rally together to drive away a shikra. They will descend to the ground to feast on emerging winged termites, hunt at dusk for small bats (such as Cynopterus sphinx) and in rare instances they may even resort to feed on carrion. In one instance a male was found feeding on a dead chick at the nest. Their calls are mimicked by drongos and this behaviour is thought to aid in stealing food by alarming other birds that the drongos associate with.
The breeding season in India is in summer from March to June. The nest is a platform similar to that of crows lined with grass. Both sexes help build the nest, twigs being carried in their feet. Like crows, they may also make use of metal wires. The usual clutch is 3 to 4 eggs (when eggs are removed they lay replacements and one observer noted that they could lay as many as 7 in a season) which are pale bluish grey stippled on the broad end in black. The incubation period is 18 to 21 days.
Captured @ Rattota - Matale main Road.





Sunday, September 7, 2014

Mongolian Plover - Migrant Bird Specie in Sri Lanka

Mongolian Plovers feed on small invertebrates such as worms, crabs and bivalves. During breeding, they feed on insects. 

Unlike other plovers which use the run-and-peck method, the Mongolian uses the "sewing-machine" feeding action more commonly used by sandpipers. This action aptly describes the way they incessantly probe with their bills for titbits.

Mongolian Plovers prefer to forage on tidal mudflats, particularly in the soft mud between the tides. But they may also forage on drier mudbanks. They are rarely found far inland. They may forage at night. While they feed, Mongolian Plovers are rather scattered, especially at low tide. But they migrate and roost in large numbers, sometimes with other waders.

 Mongolian Plovers breed discontinuously, in areas across east Asia from the Himalayas to North East Siberia, rarely in Alaska.

Like other plovers, Mongolian Plovers nest on the open ground, sometimes besides bushes or large stones. They dig shallow hollows, or use cattle footprints, and line these with pebbles or bits of plants. In the Himalayas, they nest above or beyond the tree-line, at altitudes of up to 5,500m. But in Siberia, on coastal shingle or sand dunes.

2-3 eggs are laid, and both parents incubate (22-24 days) and raise the young. But sometimes only the male raises the young. They fledged at 30-35 days.

ongolian Plovers are powerful travellers. From their northerly breeding grounds, they winter on the coasts and estuaries around the Indian Ocean and South-west Pacific (Africa, India, Sumatra to the Greater Sundas and Australia). There are 5 races which take different migration routes. Those visiting Singapore generally breed in Central or Northeast Asia.

Mongolian Plovers usually winter on muddy and sandy coasts, and occasionally at inland wetlands or on cultivated grounds. On migrations and on wintering grounds, they are found in large numbers, sometimes mixing with Greater Sand Plover (Charadrius leschenaultii), which they closely resemble. In Singapore, they come in groups of about 70. They adopt partial breeding plumage before leaving their wintering grounds.

Captured @ Yala National Park 





Thursday, September 4, 2014

Indian Roller - Resident Breeder in Sri Lanka

The Indian roller (Coracias benghalensis), is a member of the roller family of birds. They are found widely across tropical Asia stretching from Iraq eastward across the Indian Subcontinent to Indochina and are best known for the aerobatic displays of the male during the breeding season. They are very commonly seen perched along roadside trees and wires and are commonly seen in open grassland and scrub forest habitats. It is not migratory, but undertakes some seasonal movements. The largest populations of the species are within India, and Several states in India have chosen it as their state bird.

The Indian roller is a stocky bird about 26–27 cm long and can only be confused within its range with the migratory European roller. The breast is brownish and not blue as in the European Roller. The crown and vent are blue. The primaries are deep purplish blue with a band of pale blue. The tail is sky blue with a terminal band of Prussian blue and the central feathers are dull green. The neck and throat are purplish lilac with white shaft streaks. The bare patch around the eye is ochre in colour. The three forward toes are united at the base. Rollers have a long and compressed bill with a curved upper edge and a hooked tip. The nostril is long and exposed and there are long rictal bristles at the base of the bill.

Three subspecies are usually recognized. The nominate form is found from West Asia (IraqArabia) east across the Indian Subcontinent, and within India north of the Vindhyas mountain ranges. The subspecies indicus is found in peninsular India and Sri Lanka. The southern form has a darker reddish collar on the hind neck which is missing in the nominate form. The race affinis of northeastern Indiaand Southeast Asia (ThailandMyanmarIndochina) is sometimes considered a full species, but within the Indian region, it is seen to intergrade with benghalensis. The form affinis is darker, larger and has a purplish brown and unstreaked face and breast. It has underwing coverts in a deeper shade of blue

The main habitat is cultivation, thin forest and grassland. They are often seen perched on roadside electric wires. he Indian roller is distributed across Asia, from West Asia (Iraq), through the Indian Subcontinent (including Sri Lanka and the islands of Lakshadweep and Maldive Islands) into Southeast Asia.

These birds are usually seen perched on prominent bare trees or wires. They descend to the ground to capture their prey which may include insects, arachnids, small reptiles (including Calotes versicolor and small snakes and amphibians. Fires attract them and they will also follow tractors for disturbed invertebrates. In agricultural habitats in southern India, they have been found at densities of about 50 birds per km2. They perch mainly on 3—10 metre high perches and feed mostly on ground insects. Nearly 50% of their prey are beetles and 25% made up by grasshoppers and crickets.The breeding season is March to June.

Captured @ Wasgamuwa National Park.