Population densities, group size and biomass of ungulates in a lowland tropical rainforest forest of the eastern Himalayas

Large ungulate population monitoring is a crucial wildlife management tool as ungulates help in structuring and maintaining the large carnivore populations. Reliable data on population status of major ungulate prey species are still non-existent for most of the protected areas in the Indian part of the eastern Himalayan biodiversity hotspot. Twenty transects were monitored over a period of three years (2009-2011) totaling 600 km with an average length of 2 km. The estimated mean density of ungulates was 17.5 km−2 with overall density of 48.7 km−2. The wild pig Sus scrofa had the highest density (6.7 ± 1.2 km−2) among all the prey species followed by barking deer Muntiacus muntjak (3.9 ± 0.6 km−2), sambar Rusa unicolor (3.8 ± 0.5) and gaur Bos gaurus (3.5 ± 0.9 km−2). The estimated total ungulate biomass density was 2182.56 kg km−2. This prey biomass can support up to 7.2 tigers per 100 km−2. However, with two other sympatric carnivores sharing the same resources, the actual tiger numbers that can be supported will be lower. The estimated minor prey species was 31 km−2 significantly 30.6% crop damages were reported by wild pig (p = 0.01) and 35.4% was elephant (p = 0.004). This data on ungulate densities and biomass will be crucial for carnivore conservation in this understudied globally significant biodiversity hotspot.