4. DISCUSSION
The SNP is a globally recognized area by supporting the word’s largest
herd of swamp deer population (Poudel, 2007). However, at present, this
species is restricted only in SNP and BNP of Nepal, which has always
been at the risk of extinction due to the possible disturbances.
Realizing this fact, a study was conducted to find out some suitable
areas in CNP of Nepal for translocation them to establish another
sub-population (Ghimire et al., 2019), but this might take longer period
from translocation programs to establishment of viable sub-populations.
Similarly, grazing of domestic cattle is one of the severe problems in
the park area that increases competitions with the wild herbivores
(Bhattarai, 2012). Thus, we studied about the situation of interspecific
competition with spotted deer and domestic herbivores in the study area.
The main presumption of this work is that habitat is a main element of
the ecological niche (Schoener, 1989)(Chase and Leibold, 2003).
The swamp deer were present in the grasslands predominantly. Wegge et
al. (2006) also reported more late successional grasses (Narangaand Themeda spp.) and short grasses (mainly Imperata
cylindrica ) in the diet of swamp deer. A total of 55% presence of
swamp deer was recorded in the grasslands after fire where they get new
sprouts of grass as well as the ash, a source of minerals. They adapted
to all types of grassland. According to Moe and Wegge (1997),
cut-and-burned treatment gave the increase in forage quality as well as
the deer density, as the deer preferred the burned plots. Similarly, a
study conducted in Uttarakhand, India has also reported grasses and
herbs as the major diet of swamp deer (Tewari and Rawat, 2013). In
contrast, the spotted deer did not show many differences in the use of
different habitat types. Spotted deer eat both grass and browse, with
the former providing the bulk of their diet at all seasons (Kushwaha,
2016). It is predominantly a grazer but consumes more fallen leaves,
flowers and fruits in winter/dry season (Sankar, 1994; Sankar and
Acharya, 2004; Raman, 2013). It co-existed with the domestic species and
was prevalent even near human disturbance areas. The density of spotted
deer was 79 km-2 in SNP followed by swamp deer 30
km-2 and hog deer 21.6 km-2 (Karki
et al., 2015). They were found uniformly distributed in forests and
grasslands. Spotted deer avoided the areas with dense canopy cover
confirming their preference for the open forests (Pokharel and Storch,
2016). The dietary overlap of deer and cattle was highest in winter and
the competitive interactions occurred in the winter (Jenks et al.,
1996). During summer, spotted deer segregated from others from short
grasslands and predators’ presence, mixed forest and human disturbances
(Bhattarai, 2019). It was mostly recorded in the ecotones such as forest
and grassland border (Schaller, 1967; Eisenberg, 1981; Bagchi, 2001).
Mixed herds of spotted deer and swamp deer are common on Suklaphanta and
Bardia National Parks (Kushwaha, 2016).
These both deer showed the habitat partitioning during the dry season.
The spotted segregated from the short grassland and created the suitable
environment for the swamp deer. Habitat partitioning is one of the most
standard ecological mechanisms to lessen niche overlap and circumvent
competition among coexisting species (Rosenzweig, 1981; Traba et al.,
2015). Similarly, the spotted deer creates suitable environment to swamp
deer consuming the fallen leaves flowers although it is a grazer. The
distribution of domestic species shows that the potential for
interaction between the wild and domestic species exists more in theShorea forest, floodplain grassland and in the short grasslands.
But the distribution of the domestic cattle were not fund so significant
in riverine forest, tall grassland and grassland after fire. However,
the presence of domestic cattle was observed more near the boundary of
the park. Based on the information received from park staffs and filed
visit, some of the efforts made by park people to minimize the problem
of domestic cattle grazing are mesh wire fencing, electric fencing,
intensive patrolling, community awareness etc. Moreover, various habitat
management operations are done in few areas to reduce the effect of
niche and habitat overlap artificial grass cutting with tractors,
waterholes and solar water pumps, controlled fire etc. Likewise, grazing
of domestic cattle should be controlled and the plant species utilized
by wild ungulates should be protected and increased to minimize the
existing competitions. However, detail studies regarding diet
composition of these competing species in all seasons and other places
are suggested to get clear understanding and information prior to
implementing the management activities in the study area.