The globally endangered Giant Nuthatch (Sitta magna): population size, habitat availability and the implications for its conservation

Giant Nuthatch is restricted to montane habitats of southwestern China, eastern Myanmar, and northern Thailand and is globally endangered (BirdLife International 2016). While the most recent global population estimate of Giant Nuthatch was <2500 mature individuals (BirdLife International 2016), this was derived without supporting quantitative data. Therefore, it is quite possible that the actual population is much less (or potentially much more) than 2500. While the majority of remaining Giant Nuthatch habitat is in China, the amount available remains largely unquantified (BirdLife International 2016); Myanmar has now only one confirmed site (BirdLife International 2016; Thura Soe Min Htike unpubl.). Although difficult to currently quantify, Thailand comprises perhaps 5-10% of the Giant Nuthatch’s global range and possibly one-third of its global population (BirdLife International 2016; Techachoochert et al. 2018) —but equally important Thailand probably contains habitats with the strongest level of protection and is the only portion of the range with an initial quantitative population estimate (Techachoochert et al. 2018; Dr. Techachoochert was a Rufford recipient). This population estimate, while a critical first step, was still a rough approximation, not yet sufficient for taking management action because the extent of Giant Nuthatch habitat remains poorly defined. This problem was primarily due to limitations of current habitat maps which cannot clearly distinguish likely forest habitat from unsuitable forest habitat (Techachoochert et al. 2018). In summary, without adequately detailed, ground-truthed habitat maps combined with further quantitative field surveys to estimate abundance in specific forest habitats, population estimates usable for management action will not be possible for this endangered species. Therefore, for this proposed project we will follow-up on Techachoochert’s initial study in Thailand with more comprehensive survey techniques and significantly higher-quality maps to assess the status of the remaining Thai population and the reasons for its scarcity.