रविवार, 13 सितंबर 2009

Bengal florican (Houbaropsis bengalensis)

Previously known as:
Eupodotis bengalensis
Houbaropsis (1)
Male length: 64 cm
(2)Female length: 68 cm (2)Male weight: 1250 – 1700 g (2)Female weight: 1700 – 2250 g (2)
Classified as Critically Endangered (CR) on the IUCN Red List
(1), and listed on Appendix I of CITES (3).
A highly threatened and rare bird
(4), the Bengal florican is the size of a large duck (5), with mostly black plumage (6). Males have predominantly white wings, that are conspicuous when tucked against their black bodies or when in flight (5). Elongated black feathers on the head, neck and back, which are fluffed during the male's elaborate aerial displays, gives the bird a somewhat mop-like appearance (5). The plumage of female Bengal floricans does not form such a stark contrast as that of the male; they have more buff-brown plumage (2) (6), and a patch of white on the wing is seen only in flight (5). Females are also larger than males (5). Two subspecies of the Bengal florican are recognised; Houbaropsis bengalensis blandini is typically larger than Houbaropsis bengalensis bengalensis (2).
There are two distinct populations of the Bengal florican. The
subspecies H. b. bengalensis occurs in the Indian subcontinent, ranging along the border of Nepal with India and into lowland north-eastern India (2). H. b. blandini, however, occurs in Southeast Asia, in southern Cambodia and southern Vietnam (2). Over two-thirds of the global population of Bengal floricans breed on the seasonally flooded grasslands of the Tonle Sap Lake in Cambodia (7).

View a distribution map for this species at UNEP World Conservation Monitoring Centre.
The Bengal florican is an inhabitant of flat, moist grassland, which may be scattered with shrubs and bushes
(2). The most suitable habitat has areas of short grassland interspersed with patches of taller grassland (8). This provides both the short grass favoured by males for foraging and displaying, and the tall grass which is sought out during the hotter parts of the day, and where females are thought to spend most of their time (8).
The Bengal florican, although a capable flier, is most often seen walking or running along the ground
(5). It has a varied diet, feeding on insects, grasshoppers, beetles, ants, occasionally lizards and small snakes, and grasses, flowers, shoots, berries and seeds (2) (5). The proportion of these various food items varies depending on their availability, so that plant matter dominates in winter and spring, while invertebrate prey becomes more important in summer (2).
Like many birds in the Otididae family
(9), male Bengal floricans perform elaborate displays during the breeding season (5), which extends from March to June (2). Within a patch of short grass in the centre of their territory the male will fly three to four metres into the air, descend, and then rise again before diving to the ground. This exaggerated flying display is accompanied by chik chik chik calls and loud wing clapping (5). In addition to these striking aerial shows, which are typically performed at dawn and dusk (5), a standing display with its neck feathers fluffed up, and a walking and head pumping display are also part of the Bengal florican's courtship repertoire (5).
In contrast to the exhibitionist behaviour of the males, female Bengal floricans are far more secretive, visiting a male territory only briefly to breed and forage
(5). Females lay one to two eggs directly onto a scrape in the ground, situated amongst thick grass (2) (5). The glossy, olive-green eggs, flecked with purple-brown, are incubated for 25 to 28 days by the female (2). The male provides no care for the chicks, which are capable of walking, running, and feeding themselves shortly after hatching (5).
The most significant threat to the Bengal florican is the loss and alteration of its grassland habitat. Grasslands throughout its range are threatened by drainage, conversion to agriculture, overgrazing, heavy flooding, and inappropriate cutting and burning regimes
(6). The Tonle Sap grasslands, an extremely important area for breeding Bengal floricans, have declined by 60 percent since the late 1990s, with the intensification of rice cultivation playing a significant role in this loss in recent years (7). However, not all human activity should be looked upon as negative, as many grasslands, in the absence of large native herbivores, rely on activities such as grazing and burning for their existence (7). Unfortunately, reaching the correct balance of human activities is not an easy task, and the management of many grasslands, even those within protected areas, results in habitat unsuitable for the Bengal florican (8).
Hunting for sport and food may have also played a part in the decline of the Bengal florican, and remains a threat to this Critically Endangered species, particularly in Cambodia
The Bengal florican occurs in a number of protected areas, including the Royal Chitwan National Park and Royal Bardia National Park in Nepal
(8), Dudwa National Park in India, and possibly in Tram Chim National Park, Vietnam, and Ang Trapeang Thmor Sarus Crane Conservation Area in Cambodia (6). Within some of these areas, efforts are underway to maintain the valuable grasslands, such as uprooting woody vegetation (8), and a schedule of controlled fires and the collection of cut grass by locals for thatch (8) (10). This will help create more suitable habitat for the Bengal florican (8), provided that burning and cutting is carried out before the breeding season, otherwise these activities could be detrimental to the eggs or young birds (4) (10). The worrying loss of grassland habitat in the Tonle Sap led to the designation, in 2006, of 310 square kilometres of land as Integrated Farming and Biodiversity Areas. Within these areas, large scale habitat conversion is forbidden but extensive traditional use is encouraged (7).
These are laudable measures, but more conservation efforts may be required for this bird as it teeters on the edge of extinction. BirdLife International, the global bird conservation organisation, recommends that further research, surveys, grassland management and the extension and improvement of protected areas, are required to improve the status of the rare Bengal florican

कोई टिप्पणी नहीं: