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Research for the conservation of the globally Endangered Giant Nuthatch
Giant Nuthatch (Sitta magna) is a globally Endangered species restricted to lower montane habitats of southwestern China, eastern Myanmar, and northern Thailand. Despite its endangered status, crucial ecological and demographic knowledge necessary for its long-term management, remains unavailable.
Our recent quantitative research in Thailand during 2019-2020 found that the population of the Giant Nuthatch in Thailand was estimated at approximately 578 individuals, with a density of 3.7 individuals/km² across 156 sq.km of suitable habitat, predominantly composed of mature pine forest and mature pine plantation (Khamcha et al., 2022). This aligns with a study at the single-site study in Thailand (Techachochert et al., 2021), but twice that Techachochert et al. (2018) which estimated a density of around 2 birds per sq.km. In Myanmar, prior population estimate was 56 individuals in 18 sq.km. although this estimate was derived from a relatively small area in Shan state and was potentially overestimated, but the habitat structure was similar to that of Thailand. Building upon these findings, our recent study suggests that mature pine plantations have the potential to serve as suitable habitats for the Giant Nuthatch. This finding opens opportunities for future habitat restoration and habitat maintenance initiatives. Therefore, we aim to gather crucial information and to explore the potential role of pine plantations for Giant Nuthatch long-term conservation. Our study areas encompass key areas within the Giant Nuthatch range: Thailand: In 2019-2020, we conducted population abundance and suitable habitat cover estimates of Ginat Nuthatch in Thailand. Ongoing breeding ecology studies, including nest survival, nest site and nest tree characteristics, and nesting behaviors at a site which harbors the largest known subpopulation of the Giant Nuthatch in Thailand, Doi Kham Fah, Pha Dang National Park (Chiang Mai province). Future research will focus on long-term adult survival monitoring and population viability. Myanmar: In 2018, we conducted preliminary locality surveys focused on four potential forest patches in Shan state and estimated population of Giant Nuthatch for one locality (Mt. Ashae Myin Anauk Myin). Ongoing studies are focusing on assessing the population status and long-term viability of the Giant Nuthatch and identifying potential remaining strongholds and characterizing their features. China: The initial population and suitable habitat surveys have been conducted since 2021 in Yunnan, Sichuan, Guizhou, and Guangxi provinces. These research efforts mark the next crucial step in our extinction prevention strategies, we envision our strategy as a comprehensive approach with short, medium, and long-term conservation goals. Through these initiatives, we aim to contribute significantly to the conservation of the globally Endangered Giant Nuthatch and its habitat. |
Ecology and population monitoring of Asian bears in human-dominated landscapes
The bear monitoring project commenced in 2012, during which we conducted population estimation using camera traps in Khao Yai and Thap Lan National Park. We found that the density of Asiatic black bears was 6-8 individuals per 100 sq. km., and for sun bears, it was 4-6 individuals per 100 sq. km. Population abundance is crucial information for the conservation of threatened species. However, we are also concerned about population genetic issues in the fragmented landscape of the Dong Phayayen-Khao Yai forest complex. To address these concerns, we utilized hair-traps to identify genetic diversity and simulated expected changes in this diversity for the next 100 years. We considered three scenarios with varying migration rates per generation (1 = 0.02; 2 = 0.04, and 3 = 0.08). The results underscored the importance of connectivity between the two forest patches for bear long-term survival. Currently, we are monitoring bears crossing between these two forests as part of a corridor project to identify the most suitable location of a future corridor (Fig 1, bottom). Furthermore, we have collared likely nuisance bears at the forest edge, where they likely have become crop raiders (Fig 2 and 3, right). Our aim is to better understand their movement patterns in relation to fruit productivity in the forest and the crop production period.
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Satellite tracking of Asian Sparrowhawks
Raptors are at the apex of the food chain and are therefore important indicators of the state of the environment. Many species are threatened due to habitat loss and fragmentation. Determining their breeding grounds, migratory routes, and wintering sites is therefore essential for their conservation. Several hundred thousand raptors migrate annually from their temperate breeding areas passing through Thailand to largely unknown wintering grounds in Malaysia or Indonesia.
Khao Dinso, (Pencil Hill) on the coast of Chumphon province of southern Thailand, is the best site in Southeast Asia for monitoring the southward migration of raptors. Building on information gained from several years of raptor counts and ringing, we have now started a program of satellite tagging to obtain more information on the movements to and from their breeding grounds and how they spend their non-breeding season. In September 2016 three Japanese and two Chinese Sparrowhawks were fitted with 5 g satellite tags. Of the Japanese Sparrowhawks one flew down the east of the peninsular before crossing to Borneo where she settled in an area dominated by secondary growth Acacia trees. The second reached a latitude level with Kuala Lumpur near the East coast; no signals have been received since mid-October. The third flew down the west side of the peninsula and crossed over into Sumatra and on to Bangka Island. Both Chinese Sparrowhawks were tracked down the peninsula and across to Sumatra in stages of over 300 km per day.. The first has settled near Medan in an area dominated by mature oil palm and rubber plantations. The second bird stopped in southern Sumatra for nearly three weeks before continuing East with short daytime flights before settling on Adunara Island just East of Flores. |