A preliminary list of the migratory birds of the Padma charland , Rajshahi

The mighty river Padma has become compartmentalized by the development of sandbars commonly called as ‘charlands’. Charlands are gener ally a seasonal natural process of the riverine ecology, especially at the lower reach of the rivers. Sandbars or the ‘char’ is typically composed of sand, silt and/or small pebbl s, which emerge as islands within the river channel or as attached land to the riverbanks . Padma shows meandering characteristic and produce stable attached char to the riverbanks and the entire process of char formation would be completed within twelve to fifteen years (Rahman & Rahman, 2012) after 12-15 years it is turned into stable ch ar. Stable chars are more resourceful than semi stable char (Sarker t al., 2003). Construction of large dams on the rivers, v ery often affect the flow and current of the river water, res ulting in the formation of sandbars. The Padma river is known for heavy bank erosion, shifti ng channels, and sandbars that continually emerge in its course (Rahman & Rahman, 2010).

There are a large number of charlands, small and large, have been formed in the Padma river which are quite high from the water level.On the part of the river that flowing adjacent to the Rajshahi district, there are few charlands which become continuous escaping at some parts and are quite old.During monsoon greater part of this charland becomes flooded.The chars at some part may be sandy, in some parts may be alluvial, having number of water pockets or channels of different size, and have a complex ecosystem.The Padma charland is mostly sandy, with parts having sand and alluvial mixed soil.On the areas having mixed soil the natural flora had grown and people use the land for agriculture because of its rich fertile soil.There are several villages with school and community health centre at the charland of Padma lying within the Rajshahi district.At the human habitation there are a number of species of trees and plants which produce fruits and woods.Besides that, plantation programs have been carried out to protect the river side from water current.The Padma charland has a great economic value by producing huge amount of sand, different types of crops, fruits and vegetables, riverine species of fish and fire woods.
Riverine habitats (water channels and sandbars) support a wide variety of bird species, many of them nests on sandbars, others forage along or in the water channel (Claassen, 2004).During winter season a number of migratory birds invades the Padma charland, and some people hunts these birds to earn money.The Padma charland inhabited by wildlife species, but there is no information on the wildlife of this important habitat.However, the riverine fish species were recorded by several workers, but a few reports have been published (Islam & Hossain, 1983;Ali et al., 2013).Khan (1973) published a checklist of birds of Rajshahi, but did not mention the riverine species.
The present work is the result of seven years bird of watching at charlands of Padma extending from Premtali of Godagari Upazilla to Charghat Upazilla of the Rajshahi district, and here reported the list of migratory birds of the charland.

Study area and tenure:
The study area extending from Premtali of Godagari Upazilla (24°28′N 88°19.8′E) to Rajshahi Cadet College, Sardah of Charghat Upazilla (24°17′N 88°46.5′E),Rajshahi district.The charland is more or less continuous throughout this part of the river, and at some places cut by small water areas and a few channels.The distance between Premtali to Sardah is approximately 60 kilometers.
The main bird observation sites were three: (i) Premtali, covering an area of 2-3 km East-West and approximately 1 km inside the char; (ii) Rajshahi City, covering approximately 10.2 km long East-West, and around 2-4 km inside the char; and (iii) Sardah Cadet College covering approximately 2 km East-West and 0.5 km inside the char.During the survey the water areas, grasslands, and bushes were observed carefully.However, some birds were found in the dry sandy and bare soils by the side of small grasses.
Bird watching in the Padma charland was started since 2008 and still continuing.For nearly 2 years the bird watching was confined at 3-4 sites of the Rajshahi City area such as, Central Park, Boro Kuthi, Alupatti, Talaimari Shaheed Minar & Kazla.After that period the total study area between Premtali to Sardah (from west to east approximately 60 kilometers) was extensively surveyed to record the avifauna.

Habitats of the charland:
Habitats of the study area were categorized as water area and charland.The charland includes four types of habitat, such as, grass land, sandy area, agricultural land and open wood land (plantation areas).The characteristics of the soil of the habitats are different, i.e., sandy, alluvial, clay and sandy-alluvium mixed.Accordingly flora and fauna of these habitats are differently composed.

Bird watching schedule:
The study area was extensively surveyed each year from autumn (October) to summer (June).Most regular bird watching activity was in the Rajshahi City area, at least once in a fortnight.However, at the points from Kazla to Talaimari Shaheed Minar the bird observation was carried once in a week, and at the distant sites like Premtali, and Sardah it was 2-3 times in a year from December to early May.Bird watching at the Padma char was mostly started before sun rise, and spent more or less 3-4 hours.During October-June occasional survey was carried at the late afternoon till sunset, for about 2 hours.
Data Recording: Digital still camera (Nikon D3000 DSLR, 300 mm Nikor lens) and video camera (Sony DCR SR68) were used for recording data of birds of the charland.A binocular was also used to observe the birds.
During the study period total 141 species of birds were identified from the charland of the Padma river (Reza et al., 2014), of which 58 (41.43%) are migratory to Bangladesh, and the rest 83 (58.86%) are resident of this country.Among these migratory species, 47 (81.03%) are water birds and 11 (18.96%) are small passerine species (Table 1).
Total number of winter visitors were recorded as 53 (91.38%) and among them eight ( 8) are reported to be resident locally.Two species of water birds, the Tufted Pochard (Aythya fuligula) and the Asian Dowitcher (Limnodromus semipalmatus) are listed as Near Threatened species (IUCN, 2008).There are six (5) species of rare winter visitors and more five (5) species are known as uncommon winter visitors of Bangladesh.
Other than the winter visitors, there found four (4) species of summer visitors (6.98%) and two (2) species of passage migrants (3.45%).Among the summer visitors two (2) species are reported to often reside in Bangladesh.The Grey Bushchat (Saxicola ferrus) is normally a winter visitor, but sometimes they do not pass the whole season, spend few days during the journey within Bangladesh territory as a passage migrant.During the present study this bird could not recorded each year from the Padma charland.
However, flocks of ducks in the main channel were seen from distance, but absence of proper instruments good photographs could not be taken from which the species could be identified.Bird watcher James Pender reported the presence of Teal, Wigeon, Garganey, Shovelar, Common Shelduck and Mallard in the charlands of the Padma river (personal communication).Because of social risks to pass through the tall grassland, the bird watcher team could not reach near the main channel.
Among the total bird species of Bangladesh, 171 species are migratory, of which 160 are winter visitors, six (6) are summer visitors and 10 are passage migrants or spring visitors (Siddiquee et al., 2008).Migratory birds are excellent indicators of the environmental state of a region.The migratory birds play important roles in pest control (insects and rodents) of the croplands and increase the nutrients of the soil by dropping faecal materials, disperse seeds and pollinates.
The Padma charland is totally a virgin area for wildlife study and documentation.The present study is providing a list of the migratory birds of this habitat for the first time.