Niche breadth and overlap among two sympatric wild ungulates and
domestic cattle in Shuklaphanta National Park, Nepal
Understanding niche overlap with other wild species and domestic cattle
is useful to conserve and manage the wildlife in their natural habitat.
We assessed habitat niche breadth and overlap among the two sympatric
wild ungulates: spotted deer (Axis axis) and swamp deer (Cervus
duvaucelii) and, indigenous intermediate ruminants, and domestic cattle
in Shuklaphanta National Park, Nepal during the dry season. Our
objective was to explore the interspecific competition by studying the
habitat use by these species. The assumption was made that the presence
of pellets is a proof for habitat used by species. Grid based surveys
with total 96 sample plots each of size 20 m * 20 m in 6 sample grids (2
* 2 km2) with 24 sub-grids (500 * 500 m2) were used for locating pellets
group. Levin’s niche breadth and Morisita’s overlap index were
calculated to determine the niche breadth, and the habitat overlap
respectively. The Levin’s measure of niche breadth suggested that
spotted deer had the highest adaptability with an index value of 0.94
followed by domestic cattle 0.50, and swamp deer 0.33 in our study area.
Thus, it was concluded that spotted deer is a habitat generalist whereas
swamp deer are specialists and mostly preferred grasslands after a fire.
Also, there was high habitat overlap index value of 0.83 between
domestic cattle and spotted deer whereas the swamp deer and the spotted
deer showed moderate habitat overlap of 0.57. The swamp deer had low
habitat overlap as well as spatial overlap with domestic cattle.
Grassland management should be carried out for the benefit of ungulate
species as the study showed the preference of swamp deer on grassland
after a fire. Similar studies should be conducted including seasons and
places prior to implementing appropriate habitat management activities
intended to reduce interspecific competition for co-existence.