Formosan sambar deer space use and multiscale habitat selection using habitat suitability modelling and GPS telemetry

• Main Authors: Shih-Ching Yen, 顏士清
• Other Authors: Ying Wang
• Format: Others
• Language: en_US
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/vn6765

博士 === 國立臺灣師範大學 === 生命科學研究所 === 101 === Studies on the animal space use and habitat selection are required for the conservation and management of large herbivores. In Taiwan, the Formosan sambar deer (Rusa unicolor swinhoii) is listed as a protected species under the wildlife conservation law because of human overexploitation. However, its population status and life history remains unclear. In this study, we used 2 approaches to investigate habitat selection and space use of sambar deer. In the study on geographical-range scale habitat selection, we used habitat suitability modelling to identify key habitat variables and to predict potential distribution of this species throughout Taiwan. In the studies on space use and habitat selections at home-range scale, within-home-range scale, and temporal scale, we tracked the deer by using global positioning system telemetry. The habitat suitability models indicated the presence of 7,865 km2 suitable habitats for the sambar deer in Taiwan. The deer preferentially used areas that were over 1,500 m in elevation and were distant from roads. The results predicted that deer habitats are mainly located in the Central Mountain Range and Xue Mountain Range of Taiwan. However, the predicted habitats were divided into 5 regions, which were separated by 3 major mountain highways. We recommend that deer hotspots close to the highways should be monitored for the future establishment of connections among different Formosan sambar deer sub-populations. Furthermore, we collected location data from 12 collared deer (6 males and 6 females) between December 2009 and July 2013. The collared deer used higher elevation areas in hot/wet season (mean: 2,984 ± 222 m; from May to October) than in cold/dry season (mean: 2,483 ± 406 m; from November to April), which indicated a seasonal movement behavior. At the home-range scale, the deer preferred broadleaf forest, mixed forest, open habitat, and hemlock forest in the cold/dry season, and preferred fir forest, grassland, and hemlock forest in the hot/wet season. We suggested that sambar deer is a habitat generalist. In addition, the deer preferred to use areas with flatter slopes and mesic aspects (338-67°) at home-range scale, and selected areas with higher solar duration at within-home range scale in the cold/dry season. Habitat selection also occurred at temporal scale. The deer was usually closer to forested habitat in daytime than at night, highlighting its requirement of forest as shelter and cover. Moreover, the mean annual 100% minimum convex polygon home ranges were 1,078 ± 501 ha for males and 1,001 ± 346 ha for females. Overlap in home ranges of sambar deer could be as high as 80.2%, which suggested that the sambar deer did not establish exclusive territory. The mean daily displacements were 268 ± 90 m for males and 317 ± 135 m for females, with a maximum distance of 6,435 m for male and 4,422 m for female. No significant differences of home range size and daily displacement were detected between two sexes and between two seasons. In conclusion, we comprehensively studied the space use and habitat selection of sambar deer at multi-scales. The human-related disturbance would be the main factor affecting sambar deer population expansion in the future.