The South China subspecies of sika deer (Cervus nippon) has been listed as an endangered species in the IUCN Red Data List, and is also assigned to Protection Class I in the List of Wildlife under Special State Protection as designated by the Chinese State Council. In recent years, sika deer have formed several relatively isolated populations and are distributed in parts of Jiangxi, Zhejiang and Anhui provinces. Taohongling National Nature Reserve is located in Pengze County, Jiangxi Province of China, which has been designated for the protection of wild southern sika deer. The reserve is 12 500 hm² in area, of which the Core Protected Zone is 2 670 hm², the Buffer Zone is 1 830 hm² and the Experimental Zone is 8 000 hm². In the Experimental Zone, there is a considerable area of agricultural land with a high human population density. Highways surround the eastern, northern, and western boundaries of the nature reserve, while the southern border of the reserve is marked by valleys and creeks. The last estimated population of sika deer in the nature reserve was 365, which was thought to be the largest population of this sika deer subspecies. However, after strict protection for 30 years, the vegetation in the nature reserve has changed into evergreen broadleaf forests which is the local climax vegetation. Meanwhile, human activities have led to further habitat fragmentation and habitat loss. Therefore, it is necessary to carry out further studies on the population of sika deer in Taolongling National Nature Reserve for proper population conservation.
Based on the data on habitat used by sika deer in the Taohongling National Nature Reserve between March 2011 and March 2013, we used the habitat evaluation model and a Geographic Information System (GIS) to assess the suitability of the habitat for sika deer. Vegetation type, slope, aspect, elevation and human activities were selected as factors for habitat suitability assessment. The results showed that forests, including deciduous forests, coniferous forests, mixed broadleaf-coniferous forests, broad-leaved evergreen forests and bush fallow were the dominant land cover in the Taohongling area. The area of forest was 9 488.15 hm², accounting for 75.90% of the total area. In the absence of human disturbance, the areas of suitable and marginally suitable habitat were 2 233.99 hm² and 2 980.24 hm², respectively, accounting for 18.61% and 24.83% of the total area. In the presence of human activity, suitable and marginally suitable habitats decreased to about 1 224.04 hm² and 2 164.70 hm², respectively, representing 10.20% and 18.04% of the total area. Because residential areas, main roads, farming activity and timber harvesting have a strong impact on the habitat of sika deer, suitable and marginally suitable habitats have been intensively lost and isolated with the landscape fragmentation index increasing from 0.4345 to 0.5898. Using the potential available habitat area, the carrying capacity of sika deer is calculated as 568±160 individuals, but using the actual available habitat area, the carrying capacity is only 368±105. Habitat loss and fragmentation have been the main limiting factors for population recovery of sika deer in the Taohongling National Nature Reserve. We suggest that it is very important to take reasonable measures to manage forest harvesting, eliminate poaching, control the number of wild boar, and to establish habitat corridors.