Figure 8 : Charcoal
productions by men Figure
9 : Firewood collection by women
(Photo by Yacob Kassa, 2018)
Discussion
Large mammals’ distribution and abundance in the present study were
highly associated with the habitat types. In this study, the bushland
habitat has supported the highest number of mammalian species followed
by open grassland, riverine forest, and ground-water forest in both wet
and dry seasons. A similar result was obtained by Lemma and Tekalign
(2020) in the Humbo Community Based Forest, in which the highest numbers
of mammals were found in the bushland area, followed by the open
grassland, while the riverine forest supported the least number of
mammalian species. Whereas, the study of Chane and Yirga (2014) in
Borena-Sayint National Park indicated that, woodland habitat has
supported the highest number of mammalian species followed by the
riverine forest and open grassland habitat, respectively. The possible
reason for this distribution of large mammalian species might be due to
the presence of food, and water, and stability of the area from the
human disturbances. According to Tolcha et al. (2021), the availability
of quality forage and other resources determines the habitat preference
and association of ungulates. Large mammals in this study area had no
consistent distribution among the habitat types. Therefore, their
abundance significantly varies among habitats between seasons.
Balakrishinan and Easa (1986) also described that water and pasture
conditions or the combinations of both are the major factors determining
the distribution of wildlife populations in their natural habitats.
The five large mammalian species, the Burchell’s zebra, Anubis baboon,
Vervet monkey, Grants gazelle, and Colobus monkey were the most abundant
in both wet and dry seasons. The Burchell’s zebra and Grants gazelle
were favored in the bushland and open grassland habitats. Whereas,
Anubis baboon was found in all the four habitats and, Vervet monkey and
Colobus monkey were totally absent from the open and bushy grassland.
This might be attributed to the feeding behavior that it is adapted to
feed on a variety of food items. Kingdon and Largen (2003) described
that primates commonly need forested areas with tall trees. A large
number of Colobus monkey individuals were recorded in the present study
from the different habitats during both wet and dry seasons. Some
mammalian species including Guenther’s dik-dik, Bushpig, Abyssinian
hare, and Bush duiker were the least abundant during this study.
Burchell’s zebra or plains zebra was closely associated with the
availability of water and edible grasses. The present study showed that
plains zebra lives in areas where few other plain ungulates and
livestock also depend upon. The number of individuals of Lesser kudu
that was recorded in the habitats of open grassland and bushland during
both seasons is comparable with the individuals recorded by Stuart and
Stuart (2000). These animals had been frequently occurred in the open
woodland, less frequent in the wooded grasslands, and the least observed
in shrublands and open grassland areas. These animals were hardly
observed in dense forests, riverine forests, and water-logged areas. The
habitat choice of animals in the study area probably is a consequence of
competition and predation, which allow species to coexist. The number of
individuals of large mammals recorded during the wet season surpassed
the number recorded during the dry season. In the open grassland and
ground-water forest area was the common habitat for livestock and human
encroachment, which was thought to be ideal habitat for the Burchell’s
zebra and Anubis baboon species.
Gundogdu (2011) showed that livestock and human encroachments often
reduce the foraging opportunities of the wild mammals, which in turn
reduce the mammal’s opportunities of being sighted (Figure 10). Doku et
al. (2006) recorded that, a total of 7587 heads of cattle and goats from
the households in the nearby villages of Nech Sar National Park. Fetene
et al. (2019) indicated that, within the Nech Sar National Park, between
2005 and 2013, the number of livestock has increased by half. Higher
grazing pressure depreciates the scenery and the visibility of the
wildlife species of the park (Fetene et al. 2011). Besides, firewood
collection and harvesting of grasses were higher in the dry season, thus
reducing the sighting of mammals. According to Fetene et al. (2019),
fuelwood and construction wood gathering are also every day activities
that highly have an effect on the wildlife habitats of the park. Fetene
et al. (2011) also identified that grazing deteriorates the scenery and
the wildlife visibility diminishing greatly over time and putting
obstacles for the income-generating from ecotourism activities of the
park.