Black Drongo

Appearance

This bird is glossy black with a wide fork to the tail. Adults usually have a small white spot at the base of the gape. The iris is dark brown . The sexes cannot be told apart in the field. Juveniles are brownish and may have some white barring or speckling towards the belly and vent, and can be mistaken for the White-bellied Drongo. First-year birds have white tips to the feathers of the belly, while second-years have these white-tipped feathers restricted to the vent.

Distribution

The Black Drongo is found predominantly in open country and usually perches and hunts close to the ground. They are mostly aerial predators of insects but also glean from the ground or off vegetation. They are found as summer visitors to northeastern Afghanistan and northern Pakistan but are residents from the Indus Valley until Bangladesh and into India and Sri Lanka. Some populations show seasonal movements that are poorly understood. The Black Drongo can be found in savannas, fields, and urban habitats.

Behavior

They are aggressive and fearless birds, and although only 28–cm in length, they will attack much larger species that enter their nesting territory, including crows and birds of prey. This behaviour led to their former name of King Crow. They fly with strong flaps of the wing and are capable of fast manoeuvres that enable them to capture flying insects. With short legs, they sit upright on thorny bushes, bare perches or electricity wires. They may also perch on grazing animals.

They are capable of producing a wide range of calls but a common call is a two note ''tee-hee'' call resembling that of the Shikra.

Reproduction

Black Drongos breed mainly in February and March in southern India, and until August in other parts of the country. Males and females sing in the mornings during the breeding season. Courtship involves aerobatic chases and they may lock their wings and beaks together, with the pair sometimes falling to the ground. Pair bonds are retained for a whole breeding season.

The nest is a cup made with a thin layer of sticks placed in the fork of branch, and is built in a week by both the male and female. Eggs are laid close to the first rains in April. The usual clutch is three or rarely four eggs laid in a cup nest placed in the fork of an outer branch of tree. Large leafy tree such as the Jackfruit are preferred.

The eggs are pale cream to red with spots and markings and are 26 mm long and 19 mm wide. The eggs are incubated by both parents and hatch after 14 to 15 days. Nestlings are brooded for the first five days, after which the young are capable of maintaining a fairly constant body temperature. A second clutch may be laid if the first is destroyed. Nests are sometimes built in telephone poles. A nesting territory of 0.003 to 0.012 km² is maintained.

Helpers, offspring from the previous brood, have sometimes been noted to assist in feeding the fledglings at the nest of their parents. Cases of brood parasitism by the Asian Koel have been noted. An average breeding success of 44% has been noted with the main cause of fledgling mortality being shortage of insect food which in turn was dependent on rainfall.

Food

Black Drongos become active very early at dawn and roost later than many other birds. They feed mainly on insects such as grasshoppers, cicadas, termites, wasps, bees, ants, moths, beetles and dragonflies.

They sometimes fly close to tree branches, attempting to disturb any insects that may be present. They congregate in fields that are being ploughed, picking up exposed caterpillars and beetle grubs. As many as 35 birds have been seen at such congregations. They are also attracted to burning grasslands where insects are disturbed. They appear to avoid flies.