Birds in Kurigram district of Bangladesh

A study of the birds in the area adjacent to the Dharala and Brahmaputra rivers in Kurigram District, Bangladesh, was conducted between November 2000 and February 2002. A total of 105 species of birds belonging to 12 orders, 35 families and 77 genera were recorded. Out of 105 species, 51 (48.6%) were non-passerine and 54 (51.4%) passerine, 33 (31.4%) migratory and 72 (68.6%) resident. Of the non-passerine birds, 15 (29.4%) were migratory and 36 (70.6%) were resident, while, among the passerines 18 (33.3%) were migratory and 36 (66.7%) were resident. Of the total (105) species 14 (13.3%) were found to be very common, 30 (28.6%) common, 25 (23.8%) fairly common and 36 (34.3%) were rare or few. Out of 105 species, 30 (28.6%) were aquatic and semiaquatic birds and 75 (71.4%) were terrestrial. Among 105 species, 52 (49.5%) were widely distributed in Kurigram, 31 (29.5%) restricted only to the northern side, five (4.8%) to the central side, eight (7.6%) to the southern side, and nine (8.6%) species were common in two or three parts of the study area. Among the three canopy categories, 16 (15.2%) species were observed in lower canopy, 32 (30.5%) species were recorded from both lower and middle canopies, 19 (18.1%) species from upper and middle canopies and only one (1%) species was recorded from upper canopy. In the study area 37 (35.2%) species of birds used all levels of the canopy. Out of 105 species, 48 (45.7%) were insectivorous, 11 (10.4%) were grainivorous, five (4.8%) frugivorous, 10 (9.5%) were piscivorous, five (4.8%) were predatory, and 19 (18.1%) species of birds were omnivorous. Only one (1%) was vegetarian and the diet of 6 (5.7%) species could not be determined.


Materials and Methods
Field surveys were conducted along the rivers Dharala and Brahmaputra in Kurigram District from November 2000 to February 2002 to document avifaunal diversity.Birds were recorded during the first and last weeks in each month, between OPEN ACCESS | FREE DOWNLOAD 0630-1800hr everyday.
Existing roads, bridle paths, embankments, cattle trails, agricultural fields, riversides, rivers, canals and pond banks were used to cover the study area.All types of habitats were visited monthly.Most field visits were carried out on foot but sometimes vehicles were also used to cover long distances.A motorized boat was also used to cover the rivers and the canals.
Observations were made either with a pair of binoculars or by naked eyes depending on the distance of the bird.Standard literature (Ali 1996;Ali & Ripley 1983;Grimmett et al. 1999) were followed for species identification, gait, flight pattern, habitat, call and sitting posture.
Status of the recorded birds was assessed on the basis of standard methods outlined by Khan (1980).The status categories are: Very Common (VC) -bird species which were recorded on 80-100% of the field visits; Common (C) species that were observed on 50-79% of the field visits; Fairly Common (FC) species that were found on 20-49% of the field visits; and Rare (R) species that were found on less than 19% of the visits.
We determined the status of each bird species using calculations, in terms of percentage of occurrence, while earlier studies (Khan 1980(Khan , 1982) ) determined these categories based on assumption and experience.Resident and migratory species were recognized by consulting old records (IUCN 2000;Harvey 1990;Khan 1982) and through our observations.
Resident species that are found year-round and some of which were seen to make nests; Migratory species recorded only at certain times of the year.
Three canopies (levels) of vegetation could be recognized in the study area: 1. Lower canopy: maximum height of about 4m from the ground, including bushes, shrubs, small trees, and lower parts of big trees.
2. Middle canopy: 4-10m above the ground and 3. Upper canopy: above 10m high.The bird species have been listed according to the taxonomic classification of Inskipp et al. (1996).
During observations, it was noticed that many species used more than one habitat.Out of 105 species, 30 (28.6%) species used aquatic and semi-aquatic habitats including river,