634 S. U. Chowdhury et al.
2000–2008 (Salauddin & Islam, 2011). Degradation, distur- bance and conversion of seasonal freshwater wetlands thus continue to threaten Pallas’s fish eagle.
Conservation implications
There is an urgent need to develop methods to assess and monitor the status of Pallas’s fish eagle at a larger scale. Our interview surveys identified many previously unknown nests and provided new evidence on the species’ continued decline and threats. We therefore encourage the application of similar large-scale community-based interview surveys to assess the status of Pallas’s fish eagle across its breeding range. Future surveys could involve lowland districts such as Hobigonj, Moulavibazar and Sylhet. Our observations on nest site fidelity were consistent
with previous reports (BirdLife International, 2001; Steele, 2017). This site fidelity and the overall positive attitude of local communities could benefit the conservation of Pallas’s fish eagle, although species with strong site fideli- ty may also be more vulnerable to habitat degradation (Warkentin & Hernández, 1996). Tanguar Haor is recog- nized as a Ramsar site and an East Asian–Australasian Flyway Partnership Network site. The protected area (9,500 ha), however, covers only 20% of the Tanguar Haor eagle nest cluster (Fig. 1), meaning most of Pallas’s fish eagle nests are located outside the only protected area in Sunamganj district. We therefore recommend a reassess- ment of the boundary of the Tanguar Haor protected area and the implementation of an evidence-based management plan following the guidelines provided by the Ramsar Convention (Ramsar Convention Secretariat, 2007). In ad- dition, wetland restoration schemes and sustainable land- use practices outlined in the 6th National Report to the Convention on Biological Diversity (MoEF, 2019) should be implemented in other key breeding areas (Fig. 3). Our study highlights the importance of tall trees near
wetland areas, underscoring the need to preserve native trees such as B. ceiba. Existing nest trees within and out- side villages should be protected. The Bangladesh Raptor Research and Conservation Initiative initiated a nest guard- ian scheme in villages around Sunamganj city and organized a workshop in November 2020. The impact of this interven- tion will be investigated further, and if found effective, this scheme could be expanded to other areas (SUC, unpubl. data, 2020).Atotal of nine nests were in sacred, community- protected sites such as cemeteries, shrines and temples, where the preservation of tall trees creates suitable nesting places for Pallas’s fish eagle. To ensure continued availabil- ity of nest trees, suitable tree species (Table 2) should be planted, particularly in sacred sites. In addition, further con- servation action should include strategies for the rehabilita- tion of nestlings that fall from the nest during storms.
Further research is needed on the breeding and foraging
ecology of Pallas’s fish eagle, ideally comparing nesting pairs located in healthy wetlands (e.g. Tangua Haor) and de- graded wetlands in human-dominated landscapes, to deter- mine factors that influence breeding success and juvenile dispersal. We recommend the development of a global ac- tion plan for the recovery of this threatened Asian raptor.
Acknowledgements We thank the Oriental Bird Club for support- ing our fieldwork; Rhys Green and Rob Sheldon for their comments on the survey methods and reviewing a draft of this article; anonymous reviewers and M. Abdullah Abu Diyan for commenting on remote sensing; Syed Shahnoor Inam, Sourav Mahmud and Shafiqur Rahman for help during fieldwork; and the Bangladesh Forest Department for their support and encouragement.
Author contributions Funding acquisition, conceptualization, design, analysis and interpretation: SUC; fieldwork, data collection: all authors; writing: SUC; revision: SUC, MF.
Conflicts of interest None.
Ethical standards This research abided by the Oryx guidelines on ethical standards and national research guidelines of Bangladesh.
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BIRDLIFE INTERNATIONAL (2001) Threatened Birds of Asia: The BirdLife International Red Data Book. BirdLife International, Cambridge, UK.
BIRDLIFE INTERNATIONAL (2020) Species factsheet: Haliaeetus leucoryphus.
datazone.birdlife.org/species/factsheet/pallass-fish- eagle-haliaeetus-leucoryphus [accessed 15 May 2020].
CHOWDHURY, S.U. (2018) Nature Quest: a quest for eagle nest. The Daily Star, 23 February 2018.
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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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