2019-07-01_neScholar

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species and engineers of forest.
Asian elephants are the largest
terrestrial species found in tropical
and subtropical habitats of Asia.
This endangered species occupies
a wide geographic range covering
13 countries located in south
and south-east Asia. They play a
significant role in maintaining the
ecosystem functioning by physically
transforming the forest as they
move through it. They knockdown
trees creating light gaps; trample
vegetation clearing the undergrowth;
provide water by digging holes in
dry riverbeds; depressions created by
them trap rainfall; their paths acts as
firebreaks and river water channel;
act as seed dispersers; fertilize soil
by their dung; and provide food for


birds by disturbing small reptiles,
amphibians or insects while moving
through the high grass.

In the beginning of the 20th century,
more than 100,000 Asian elephants
may have existed. But their numbers
have dwindled to less than 50,000
in the past three generations. Their
habitats have also reduced to 15%
of its historic range. According
to Ministry of Environment
Elephant Census 2017, the elephant
population in India has decreased
by 10% to 27,312 and that alone
accounts for about 50% of the
Asian elephant population. Most
of their habitats in Asia are close
to human settlements, and hence
responsible for increasing incidences
of human-elephant encounters.
Additionally, these habitats are at risk
due to land use changes involving
conversion of their habitats for
agriculture, urbanization, industry
and transportation. Climate change,
land use changes, changes in water
cycle and other influencing factors
will result in loss of their habitats. It
is estimated by a team of researchers
that Asian elephants may lose up to
42 percent of suitable habitats in
India and Nepal by 2070.

The Asian elephant’s females are
social and live in herds comprising
of related females and led by the
oldest female, the matriarch. Males
usually live alone and sometime
form small groups. The home range
of an Asian elephant herd can vary
from an average of about 250 sq km
(in protected areas) to over 3500
sq Km (in highly degraded and
fragmented habitats). Greater the
degree of degradation of habitats,
the farther an elephant herd has to
roam in search of food and water.
They are migratory species moving
considerable distances within a short
period of time following well defined
seasonal migration routes. Corridors
and routes are crucial for the survival

of the species as it allow elephants
to safely migrate, access food sources
and establish genetic links between
herds. Some factors along the routes
and corridors can limit the migration
of elephants such as presence of
traffic on the roads, construction of
steep retaining walls and the presence
of human population.

The Asian elephants feed on a diverse
array of foods like grasses, woody
plants and some cultivated crops
such as sugar cane and banana. An
adult elephant can consume ca. 150
kg of food daily. They are found
across range of diverse habitats
including grasslands, tropical
evergreen forests, semi-evergreen
forests, moist deciduous forests,
dry deciduous forests and dry thorn
forests, in addition to cultivated and
secondary forests and scrublands.
These generalists’characteristics
increase their resilience to climate
change. However, several other
traits increase their chances of
extinction due to changes in the
climate, particularly temperature
and precipitation. These traits
include diminishing population size,
intolerance to very high temperatures
(above 45 ̊C), occurrence of invasive
plant species such as, Lantana
sp. in their range wiping out their
usual food sources and higher
vulnerability to several diseases
(septicemia, hemorrhagic septicaemia
(Pasteurellosis), anthrax, foot and
mouth disease, elephant pox, rabies,
tetanus, encephalomyocarditis virus,
pneumonia, dysentery,tuberculosis,
endotheliotropic elephant herpes
virus and a number of parasites).

The ability of the Asian elephant to
respond to changes in climate or its
adaptive capacity is low. This is due
to limited dispersal ability owing to
increasing habitat fragmentation;
a long generation time of 20 to 25
years; a slow reproductive rate (a long
gestation period: 22 months, age

neScholar 0 vol 4 0 issue 4 27
ASIAN ELEPHANT I NATURE
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