ফেঁচু

ফেঁচু^১ (Black Drongo, বৈজ্ঞানিক নাম-Dicrurus macrocercus) 'Dicruridae' পৰিয়ালৰ অন্তৰ্ভুক্ত এবিধ মজলীয়া আকাৰৰ চৰাইৰ প্ৰজাতি। দক্ষিণ এছিয়াৰ ইৰান, ভাৰত, শ্ৰীলংকাৰ পৰা চীন তথা ইণ্ডোনেছিয়া লৈকে ই স্থানীয় ভাৱে প্ৰজনন কৰে। ইয়াৰ সমগ্ৰ দেহটো ক'লা বৰণৰ, নেজ খাঁজকটা (forked)। ই প্ৰধানকৈ পোক-পতংগ খাই জীয়াই থাকে বাবে খেতি-পথাৰৰ আশে পাশে এই চৰাইবিধ পৰ্য্যাপ্ত পৰিমাণে দেখা পোৱা যায়। ফেঁচুক সাধাৰণতে অতিমাত্ৰা আক্ৰমণাত্মক আচৰণৰ বাবে জনা যায়। নিজৰ টেৰিটৰীৰ ভিতৰত সোমোৱা যিকোনো সৰু-বৰ চৰাইকে ই খেদি পঠিয়ায়।

টেক্স'নমি

ফেঁচুক এসময়ত 'Drongo' পৰিয়ালৰে অন্য এবিধ প্ৰজাতি 'Fork-tailed Drongo' ৰ উপ-প্ৰজাতি বুল গণ্য কৰা হৈছিল।। বৰ্তমান এই দুয়োটাকে ভিন্ন প্ৰজাতি (জীৱবিদ্যা) বুলি স্বীকৃতি দিয়া হৈছে।^২ with the Fork-tailed Drongo restricted to Africa and separated from the Asian range of the Black Drongo.^২

ফেঁচুৰ এতিয়ালৈকে সাতটা উপ-প্ৰজাতি চিনাক্ত কৰা হৈছে^২ -

• Dicrurus macrocercus albirictus-উত্তৰ ভাৰত
• Dicrurus macrocercus minor-শ্ৰীলংকা^৩
• Dicrurus macrocercus cathoecus -থাইলেণ্ড, হংকং, চীন^৪
• Dicrurus macrocercus thai
• Dicrurus macrocercus cathoecus
• Dicrurus macrocercus javanus -জাভা, বালি
• Dicrurus macrocercus harterti^২

বিৱৰণ

ফেঁচুৰ দেহৰ বৰণ জিলিকা ক'লা আৰু নেজডাল দকৈ দুভাগ কৈ কটা। পূৰ্ণবয়স্ক মতা ফেঁচু চৰাইৰ 'গেপ'(gape)ৰগুৰিত বগা দাগ থকা দেখা যায়। The iris is dark brown (not crimson as in the similar Ashy Drongo). 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.^৫

They are aggressive and fearless birds, and although only 28–cm (11–in) 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.^৬ With short legs, they sit upright on thorny bushes, bare perches or electricity wires. They may also perch on grazing animals.^৭

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 বৰীশেন (Accipiter badius).^৩

বিতৰণ তথা বাসস্থান

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.^৩ Some populations show seasonal movements^৭ that are poorly understood.^৮ The Black Drongo can be found in Savannas, fields, and urban habitats.

Black Drongos were introduced just before the Second World War from Taiwan to the island of Rota to help in the control of insects. It is believed that they dispersed over the sea to the island of Guam in the 1950s. By 1967, they were the fourth most commonly seen birds in roadside counts on Guam and are today the most abundant bird there.^৯১০ Predation by and competition from Black Drongos have been suggested as factors in the decline of endemic bird species such as the Rota Bridled White-eye^১১ and the Guam Flycatcher.^৯১২

আচৰণ

খাদ্য

Black Drongos become active very early at dawn and roost later than many other birds. They feed mainly on insects such as grasshoppers, cicadas,^১৩ 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.^১৪ They associate with Common Mynas, Cattle Egrets and other birds that share a similar diet and habitat.^১৫ Drongos benefit from this association and are more successful in their foraging.

প্ৰজনন

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 can include aerobatic chases and they may lock their wings and beaks together, with the pair sometimes falling to the ground. Displays may be made on the ground.^১৬ 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.^৫ 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 (1.05 in) and 19 mm wide (0.75 in). 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.^৫ A second clutch may be laid if the first is destroyed.^৭ Nests are sometimes built in telephone poles.^১৭ A nesting territory of 0.003 to 0.012 km² (0.3 to 1.2 Hectares) is maintained.^৫

আক্ৰমণাত্মক আচৰণ

Their habit of driving away predators from near their nests is believed to encourage other birds such as orioles, doves, pigeons, babblers,^১৮ and especially bulbuls, to nest in the vicinity.^১৯২০ In one study 18 of 40 nests had Red-vented Bulbuls nesting within 10 মিটাৰ.^৫ An abnormal case of a Red-vented Bulbul feeding the chicks of a Black Drongo at their nest has been recorded.^২১

They are so aggressive that they may sometimes land on large birds of prey and peck them when mobbing.^২২

মানুহৰ সৈতে সম্পৰ্ক

Their habit of preying on bees^২৩ makes them a nuisance to bee-keepers, but farmers attract them to their fields using artificial perches in fields to encourage them to feed on pest insects.^২৪২৫

লগতে চাওক

• Bhujle,BV; Nadkarni,VB (1980) Histological and histochemical observations on the adrenal gland of four species of birds, Dicrurus macrocercus (Viellot), Centropus sinensis (Stephens), Sturnus pagodarum (Gmelin) and Columba livia (Gmelin). Zool. Beitrage 26(2):287–295.
• Lamba,BS (1963) The nidification of some common Indian birds. 3. The Black Drongo (Dicrurus macrocercus Viellot). Res. Bull. Panjab Univ. 14(1–2):1–9.
• Shukkur,EAA; Joseph,KJ (1980) Annual rhythm in the Black Drongo Dicrurus adsimilis (family Dicruridae, Passeriformes, Aves). Comparative Physiol. Ecol. 5(2):76–77.
• Shukkur, EAA (1978) Biology, Ecology and Behaviour of the Black Drongo (Dicrurus adsimilis). Thesis, University of Calicut.

বাহ্যিক সংযোগ

• Black Drongo videos, photos & sounds on the Internet Bird Collection