Thursday, September 26, 2013

ASHY DRONGO V/s BLACK DRONGO

Ashy Drongo                                                                  Black Drongo









        

This blog focuses on identification of both species. I observed that many bird watcher mistaken Ashy Drongo (Dicrurus leucophaeus) as Black Drongo (Dicrurrus macrocercus).

In India there are 10 species of Drongo found. Out of above referred two species are seen on plains of peninsular Inida. Black Drongo breeding resident of peninsular India while Ashy Drongo winter visitor.

Now it is high time for arrival of Ashy Drongo in a coming week or two. Its arrival creates confusion among birders. Ashy Drongo breeds in Himalayan hills; I have seen their active nests in Eagle Nest, Arunachal Pradesh and Musniyari Uttarakhand in the month of may.

Some similarity makes both look alike but if we observe keenly major differences unearth. Behaviour and habitat are the simple clews to identify this species. Here I discuss some similarity and differences.

 

Table :1 Similarity.

Black Drongo Dicrurus macrocerus=Forked long tailed
Ashy Drongo Dicrurus leucophaeus=Forked tail and gleaning.
Size 28 cm
29 cm
Over all colour black
Over all colour black
Seen near human habitat
Seen near human habitat
Forage on insects some time flower nectar
Forage on insects some time flower nectar
Arboreal
Arboreal
Diagnostic long and forked tail
Diagnostic long and forked tail

Table:- 2 Differences


Black Drongo (Dicrurus macrocerus)
Ashy Drongo (Dicrurus leucophaeus)
Size and Shape
Shape rather stocky compared with Ashy. For of the tail is wide angle.
Slender built for of the tail shows acute angle
Colour
Colour over all black shows glistening sting on wings. Imm shows white feathers on breast and belly.
Over all black chest and belly dull black. Shows gleaning sting on mantle and also wings
Rectal spot
Usually shows rectal white spot
No such spot
Iris
Brownish
Scarlet
Status
Resident breeds locally.
Winter visitor arrives in Oct 1st week. Breeds in Himalayan ranges
Habitat
Open country along side of the roads and agricultural fields grazing cartels etc.
Prefer forest and wooded area and high rising trees hence happens in garden and groves even in thickly populated cities. Visit back yard of house where it find flowering and insects like bees etc.
Food
Feeds on insects but they are mostly picked from ground. Birds perches on moderate elevation and watch the movement of prey then either land or hovers few inches above ground and picks up disturbed creature. Some time kills large prey like small bird, lizard etc. This bird rarely feeds on nectar.

Seen on back of grazing cattle and near farmer in action of agricultural activities. Farmer burns remaining of the crop which disturbs insect, attracts this bird.
Feeds on insects but they generally caught in the air diving stooping in the air.. Prefer high rising trees and feeds on insects flying on that elevation. Every flowering tree attracts this bird as the tree attracts bees and insects. This bird can be seen hunting near Honey bee colony or beehive. Feeds on all types of flower nectar like Palas, Pangara, Bombax, Austrelian Bhabul etc. Never stays in one area for longer time. Keep moving in search of food. Visits to flowering trees follows precise time schedule.
Call
Active during breeding otherwise very silent call when competition for food or territory occurs (see attached file)

Once food territory is fixed they remain there till breeding season arrives in April.
Very vocal always keep calling. If in pair they are very noisy and many time seen in pair.
Rising and retiring call are most diagnostic. Noise really disturbs silence of forest even housing colonies.

This bird often mimics Shikra
Migration
Local breeder but in winter population rises abnormally this may be because of birds arrives from breeding ground to feeding grounds with young generation.

We are taking census of one garbage dump of Miraj town in December and June which reveals in Dec average 64 bird counted while in May only one pair registered.

As per Whistlers Popular Hand Book of Indian Birds this rise in number may be because of local migration from plains of North to Peninsular India. Need interaction with bird watchers in Northern India. If they observe drastic reduction in population in winter then it may migrate to south.
Arrives from Himalayan ranges in first week of Oct (It may differs by week or more according to geographical location) and depart to home ground in 2 nd week of April. Some birds shows even late April bur very rare.
 

This is the best time to observe this two birds to confirm my observation. This observations are based on my personal observation and most of them near my native place and in western ghat. It may not be necessarily tailed with all other parts.

My appeal is that please concentrate on this two bird during coming 6 to 7 months and give me your feed back with details of location etc.

 

 

Sharrad Apte

Bird Song Education Research and Publication

bser@birdcalls.info

www.birdcalls.info