The Ecology of the Bhutan takin Budorcas whitei in Jigme Dorji National Park, Bhutan

Abstract

<p>The Bhutan takin <i>Budorcas whitei</i>, a large gregarious forest-dwelling ungulate, is endemic to Bhutan and categorized as 'vulnerable' by the IUCN Red List of Threatened Species. The word 'takin' is used hereafter to denote both singular and plural. Prior to my work, there had been only one study on this species which investigated its diet within its summer habitat. Prior to beginning my field research on takin, I assessed its current distribution and conservation status in Bhutan from information gathered through publications, field surveys, interviews and unpublished reports. The assessment resulted in documenting some interesting facts such as establishing the Bhutan takin as endemic to Bhutan; the takin's site fidelity to hot spring and salt lick areas, and their distribution along the river valleys which are important landscape features for habitat selection. I identified additional threats to the takin like anthropogenic disturbance and disruption to migration routes, threats posed by domestic livestock including dogs, and the risk of zoonoses disease transmission.</p><p> I examined takin migratory movement between their winter and summer habitat, and their summer habitat use in the Tsharijathang Valley of Jigme Dorji National Park, Bhutan, from 2013-2015 using GPS collars. Bhutan takins are seasonal migrants from warm broad-leaved forest to alpine meadow within the altitude range of 1500 m to 5550 m asl (meter above sea level, hereafter using 'm' instead of 'm asl'). GPS-collars were placed on 13 adult takins (7 males and 6 females) to document these seasonal movements. Because of animal welfare concerns, sub-adult animals could not be collared. Takin, on average, travelled about 4 km per 24-hour period, about a third of which occurred at night. There was high site fidelity and overlap of habitat in their summer range that led to short distance travel which ultimately resulted in a smaller summer home range. The Minimum Convex Polygon (MCP) home range estimate for takin in the summer habitat at a 95% isopleth ranged between 3.35 - 14.21 km², while the kernel utilization distribution (KUD) estimate ranged between 7.55 to 27.4 km². A male takin (TM2724) collared on 8 July 2013 provided partial data on takin migration from its summer range to its winter range before the GPS collar ran out of memory on 27 September 2013. However, this inaugural migration data showed that the animal travelled 26.68 km in the rugged mountainous terrain in three days, and part of which was along a ridgeline between 5007 to 5374 m. The male migrated to the area around Zomling, Lingzhi and Barshong, Naro of Thimphu district.</p><p> Habitat use by the Bhutan takin in their summer (alpine meadows) and winter (broadleaf forest) habitats was examined by comparing floristic composition in the areas that were used by takin compared to those that were not used. A collective total of 58 plots were laid in the summer habitat (30 plots, 15 each in the used and unused area) and in the winter habitat (28 plots, 14 each in the used and unused area). Principal component analysis (PCA) showed that the first three principal components explained about 70 percent of the total variance between used and unused sites. PC1 had significant loadings from variables like altitude, herb count and herb mean height, PC2's significant variables were tree count and tree mean DBH while PC3 had significant loadings from shrub mean height. Analysis of variance using distance matrices showed that there were significant differences between the used and unused plots in both habitats (summer <i>F</i>_{1, 28} = 69.36, <i>p</i> < 0.01; winter <i>F</i>_{1, 26} = 3.89, <i>p</i> < 0.01). The analysis of data from the summer habitat showed significant difference between used and unused plots that was driven by differences in plant species and diversity, with used plots having significantly more trees and shrubs which the takin prefers as cover and for rest during midday.</p><p> Local knowledge and perceptions by people towards the takin was assessed by conducting facetoface semi-structured interviews on 169 residents of Jigme Dorji National Park from the Laya Geog (takin summer habitat; 91 residents) and Khatey and Khamey Geogs (takin winter habitat; 78 residents). Most respondents knew the takin was the national animal and a significantly higher proportion also knew its protected status. There was a significant difference in knowledge based upon respondents' residence whereby residents in the takin's summer habitat possessed more knowledge on the vulnerable status of takin. The summer habitat has affluent residents that benefit from collection of the prized medicinal Chinese caterpillar fungus or 'Cordyceps' <i>Ophiocordyceps sinensis</i>; this in turn allows them better access to media (e.g. television and radio) that expose them to pertinent information and campaigns surrounding the takin. Most respondents expressed positive feelings towards the takin and supported its protection.</p><p> This strong positive attitude and awareness by residents is promising but it is strongly recommended that the park develops diverse education programs targeting different age groups and learning capabilities in continuing to maintain local support and stewardship. Conservation of the takin, however, is not without its challenges and requires a commitment to reduce anthropogenic disturbance such as land use change from road construction, infrastructure for power transmission lines, unregulated harvesting of natural resources notably the prized cordyceps, competition for foraging resources from domestic livestock, and most critically, the spread of zoonotic disease transmission from domestic livestock. Understanding habitat use by takin and associated preferred habitat variables amidst various anthropogenic threats is integral towards ameliorating damage to takin habitat and preventing further loss. Furthermore, the Jigme Dorji National Park management should reinforce the implementation of the tripartite Tsharijathang Agreement whereby domestic livestock are not grazed in the Tsharijathang Valley a month prior to the takin's arrival. The valley needs urgent protection as a declared takin sanctuary to provide a safe habitat for takin during their breeding season. This valley attracts different congregating herds from several wintering habitats around Thimphu, Paro, Gasa and Punakha, and it is crucial to facilitate the current genetic exchange to increase population vigor for the long-term survival of the takin, Bhutan's national animal.</p>