628 S. U. Chowdhury et al.
FIG. 1 (a) Locations of community-based interview surveys and Pallas’s fish eagle Haliaeetus leucoryphus nests in (b) the study area in Sunamganj and Netrokona districts of north-east Bangladesh. The inset map (c) indicates the location of the initial exploratory survey within a 3-km radius around nine known eagle nests.
information about well-known, large and/or easily identifi- able species or those with a high cultural or socio-economic value (Jones et al., 2008). However, there are potential errors and biases in the collection, interpretation and quan- tification of interview-based data, especially when these are gathered by untrained observers or if the study requires identification of less well-known species (McKelvey et al., 2008; Turvey et al., 2014). Pallas’s fish eagle is one of the largest eagles in the Indian subcontinent (Naoroji, 2006) and well known to people in north-east Bangladesh because of its loud and frequent calls during the breeding season (Chowdhury, 2018). In addition, the eagle has long been associated with the traditions, cul- ture and religion of local communities, especially amongst Hindus, who celebrate the arrival of the eagle during the early dry season (August–September) and organize a fes- tival, locally known as Raio Uutshav, in their villages (BirdLife International, 2001; Sourav et al., 2011). Because of these traditional linkages between Pallas’s fish eagle and local communities, utilization of the same habitat and ab- sence of any similar species in the area (Siddiqui et al., 2008) that could lead to misidentification, we were able to develop a community-based interview survey to determine the status of the species in north-east Bangladesh. Recognizing the need for conservation action, we pro-
vide the first comprehensive survey of the species’ breeding population and its habitat requirements in north-east Bangladesh. We conducted an extensive community-based interview survey to investigate spatial and temporal pat- terns in Pallas’s fish eagle nesting and possible changes in the number of nesting territories. Using the information
derived from interviews, we then visited presumed nesting locations to determine occupancy, nest site selection and habitat attributes. In addition, we conducted opportunis- tic surveys, compiled recent observations on previously reported Pallas’s fish eagle breeding sites in Bangladesh and identified priority breeding areas in the north-east of the country. We discuss the significance of our findings for the conservation, monitoring andmanagement of this species.
Study area
We conducted this study in the seasonally flooded fresh- water wetlands (known locally as Haors) and human- modified landscapes (agricultural fields and villages) of north-east Bangladesh, covering c. 4,150 km2. Ninety-two per cent of the study area is located within Sunamganj and 8% in Netrokona administrative districts of the Sylhet Division (Fig. 1). SunamganjisnearCherrapunji in Meg- halaya State of north-east India, with a mean annual rainfall of .5,000 mm, one of the highest levels of rainfall globally. During the rainy season (May–September), large areas of Sunamganj are submerged (Geisen et al., 2000). Most villagers live on areas of higher ground that are surrounded by trees. Mean monthly temperature and humidity in the study area range from8.5 °C and 64%inwinter to 32 °C and 83%in sum- mer(Geisen et al.,2000).Water levels fallduringthedryseason (October–April), resulting in numerous shallow waterbodies throughout the study area, with tree cover mainly in the vil- lages. These circular floodplain depressions are important ha- bitats for fish and waterbirds (Geisen et al., 2000;Muzaffar & Ahmed, 2007), on which Pallas’s fish eagle depends.
Oryx, 2022, 56(4), 627–635 © The Author(s), 2021. Published by Cambridge University Press on behalf of Fauna & Flora International doi:10.1017/S0030605321000314
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