Asian elephant (Elephas maximus)
Description
Asian elephants (Elephas maximus) are smaller than their African savannah relatives (Loxodonta africana) and have many other physical features that distinguish them. The ears are smaller and the back is more rounded so that the crown of the head is the highest point of the body. One of the characteristic features of an elephant are the modified incisor teeth which are known as tusks, however, only some male Asian elephants have tusks, whilst females (cows) have 'tushes' instead, that are seldom visible. Elephants support their stocky body on stout, pillar-like legs, and the nose and upper lip are joined and elongated into a trunk. The trunk provides a wide variety of functions from feeding, vocalisation, bathing and fighting; those of the Asian elephant have only a single finger-like process on the base, whilst the African elephant has two. The thick, wrinkly skin covering the body is a greyish-brown colour and very dry.
Size
Bull Asian elephants commonly weigh from 4,500 to 5,400 kg (9,900 to 12,000 lb)
and are often around 2.7 m (8.9 ft) high at the shoulder. Females typically
weigh around 2,000 to 4,000 kg (4,400 to 8,800 lb) and reach an average of 2.4 m
(7.9 ft) at the shoulder. Head-and-body length is from 5.5 to 6.4 m (18 to 21
ft), with the tail measuring 1–1.5 m (3.3–4.9 ft) long. The skeleton constitutes
about 15% of their body weight. One extraordinarily large bull elephant living
in captivity at the Oregon Zoo, weighed 14,500 pounds (6,590 kg) in 2008.
The sizes of wild Asian elephants, especially males, have been exaggerated in
the past. Record elephants may have measured as high as 3.7 m (12 ft) at the
shoulder. Shoulder height is estimated using the rule of thumb of twice the
forefoot circumference.
The height of the adult male usually does not exceed nine feet [2.7 m], and that
of the female eight feet [2.4 m]; but these dimensions are occasionally
considerably exceeded. George P. Sanderson measured a male standing nine feet
seven inches [2.9 m] at the shoulder, and measuring twenty-six feet two and
one-half inches [8 m] from the tip of the trunk to the extremity of the tail;
and he records others respectively reaching nine feet eight inches [2.9 m] and
nine feet ten inches [3 m] at the shoulder. An elephant shot by General Kinloch
stood upward of ten feet one inch [3.1 m]; and another measured by Sanderson ten
feet seven and one-half inches [3.2 m]. These dimensions are, however, exceeded
by a specimen killed by the late Sir Victor Brooke, which is reported to have
reached a height of eleven feet [3.4 m]: and there is a rumour of a Ceylon
elephant of twelve feet [3.7 m]. That such giants may occasionally exist is
indicated by a skeleton in the Museum at Calcutta, which is believed to have
belonged to an individual living between 1856 and 1860 in the neighbourhood of
the Rajamahal hills, in Bengal. As now mounted this enormous skeleton stands
eleven feet three inches [3.4 m] at the shoulders, but Mr. O. S. Fraser, in a
letter to the Asian newspaper, states that it is made to stand too low, and that
its true height was several inches more. If this be so, there can be no doubt
that, when alive, this elephant must have stood fully twelve feet.
The heaviest bull elephant recorded was shot by the Maharajah of Susang in the
Garo Hills of Assam, India in 1924, and weighed 8 tonnes (8.8 short tons), stood
3.35 m (11.0 ft) tall and 8.06 m (26.4 ft) long from head to tail.
Range Description:
Asian elephants formerly ranged from West Asia along the
Iranian coast into the Indian subcontinent, eastwards into South-east Asia
including Sumatra, Java, and Borneo, and into China at least as far as the
Yangtze-Kiang. This former range covered over 9 million km² (Sukumar 2003).
Asian elephants are now extinct in West Asia, Java, and most of China The
western populations (Elephas maximus asurus) were probably extinct by 100
BC, and the main Chinese populations (sometimes referred to as E. m.
rubridens) disappeared sometime after the 14th century BC. Even within its
surviving range in South and South-east Asia, the species has been in retreat
for hundreds if not thousands of years, and generally survives only in highly
fragmented populations (Olivier 1978; Sukumar 2003; Blake and Hedges 2004).
Asian elephants still occur in isolated populations in 13 states, with a very
approximate total range area of 486,800 km² (Sukumar 2003; but see Blake and
Hedges 2004). The species occurs in Bangladesh, Bhutan, India, Nepal, and Sri
Lanka in South Asia and Cambodia, China, Indonesia (Kalimantan and Sumatra) Lao
PDR, Malaysia (Peninsular Malaysia and Sabah), Myanmar, Thailand,
and Vietnam in South-East Asia. Feral populations occur on some of the Andaman
Islands (India).
The elephants of Borneo were believed to be feral descendants of elephants
introduced in the 14th–19th centuries (Shoshani and Eisenberg, 1982; Cranbrook
et al., 2008); however, recent genetic evidence suggests they are indigenous to
the island (Fernando et al., 2003; but see Cranbrook et al., 2008).
The species was once found throughout Sri Lanka, but today elephants are
restricted mostly to the lowlands in the dry zone where they are still fairly
widespread in north, south, east, north-western, north-central and south-eastern
Sri Lanka; but with the exceptions of small remnant populations in the Peak
Wilderness Area and Sinharaja Area, elephants are absent from the wet zone of
the country. The species continues to lose range to development activities
throughout the island.
Once widespread in India, the species is now restricted to four general areas:
north-eastern India, central India, north-western India, and southern India. In
north-eastern India, the elephant range extends from the eastern border of Nepal
in northern West Bengal through western Assam along the Himalaya foothills as
far as the Mishmi Hills. From here it extends into eastern Arunachal Pradesh,
the plains of upper Assam, and the foothills of Nagaland. Further west, it
extends to the Garo Hills of Meghalaya through the Khasi Hills, to parts of the
lower Brahmaputra plains and Karbi Plateau. Elsewhere in the south in Tripura,
Mizoram, Manipur, and the Barak valley districts of Assam, isolated herds occur
(Choudhury, 1999). In central India, highly fragmented elephant populations are
found in the States of Orissa, Jharkhand, and the southern part of West Bengal,
with some animals wandering into Chattisgarh. In north-western India, the
species occurs in six fragmented populations at the foot of the Himalayas in
Uttaranchal and Uttar Pradesh, ranging from Katerniaghat Wildlife Sanctuary in
Bahraich Forest Division in the east, to the Yamuna River in the west. In
southern India, elephants occur in the hilly terrain of the Western Ghats and in
parts of the Eastern Ghats in the states of Karnataka, Kerala, Tamil Nadu, and,
relatively recently, Andhra Pradesh. There are eight main populations in
southern India, each fragmented from the others: northern Karnataka; the
Crestline of Karnataka–Western Ghats; Bhadra–Malnad; Brahmagiri–Nilgiris–Eastern
Ghats; Nilambur–Silent Valley–Coimbatore; Anamalais–Parambikulam;
Periyar–Srivilliputhur; and Agasthyamalais.
In Nepal, elephants were once widespread in the lowland Terai, but are now
restricted to a few protected areas along the border with India: Royal Chitwan
National Park, Parsa Wildlife Reserve, Royal Bardia National Park, and Royal
Suklaphanta Wildlife Reserve, and their environs. There is some movement of
animals between these protected areas and between Bardia National Park and the
adjacent parts of India.
In Bhutan, all the existing elephant populations are found along the border with
India. They are reported from Royal Manas National Park, Namgyal Wangchuk
Wildlife Sanctuary, Phipsoo Wildlife Sanctuary, and the Reserve Forests such as
Khaling Wildlife Sanctuary, Dungsum, and Mochu. In the past, elephants made
seasonal migrations from Bhutan to the grasslands of India during the wetter
summer months of May to October, returning to their winter range in Bhutan from
November. Now these movements are restricted as a result of loss of habitat on
the Indian side and fragmentation of habitat on the Bhutan side.
In Bangladesh, the species was once widespread, but today it is largely
restricted to areas that are relatively less accessible to humans, mainly
Chittagong and the Chittagong Hill Tracts in the southeast. In addition, some
animals periodically visit the New Samanbag area of Maulvi Bazar District under
the Sylhet Forest Division in the north-east of the country, coming from the
neighbouring Indian states of Tripura, Meghalaya, and Assam.
The Asian elephant has a wide, but highly fragmented, distribution in Myanmar.
The five main areas of elephant abundance are: the Northern Hill Ranges, the
Western Hill Ranges, Pegu Yoma (central Myanmar), Tenasserim Yoma (in the south,
bordering Thailand), and Shan State or eastern Yoma.
In Thailand, the species occurs mainly in the mountains along the border with
Myanmar, with smaller fragmented populations occurring in the peninsula in the
south (in several forest complexes, south to the border with Malaysia); in the
northeast (in the Dong Phaya Yen-Khao Yai forest complex, including Khao Yai
National Park, and the Phu Khieo-Nam Nao forest complex); and in the east (in a
forest complex composing the Khao Ang Runai Wildlife Sanctuary, Khao Soi Dao
Wildlife Sanctuary, Khao Khitchakut National Park, and Khao Cha Mao National
Park).
In Cambodia, elephants are primarily found in the mountains of the south-west
and in Mondulkiri and Ratanakiri Provinces. Recent surveys in Keo Sema District
(Mondulkiri Province) suggest that important numbers may remain in that area
(WCS unpubl. data). Elsewhere, Asian elephants persist in Cambodia in only
small, scattered populations (Duckworth and Hedges, 1998).
In the Lao People’s Democratic Republic, elephants remain widely but very
patchily distributed in forested areas, both in the highlands and lowlands. Two
important and likely viable populations are known, one in Xaignaboli Province
west of the Mekong and one on the Nakai Plateau. Other potentially important
elephant populations occur in Phou Phanang and Phou Khao Khoay in Vientiane
Province; Phou Xang He in Savannakhet Province; Dong Ampham and Dong Khanthung,
including Xe Pian, close to Cambodian border; and Nam Et, Nam Xam, Phou Dendin,
and Nam Ha in the north, close to the Viet Namese and Chinese borders.
In Vietnam, only a small population persists now. In the northern part of the
country there are no elephants left, barring occasional wanderers into Son La
from Lao PDR. In the central and southern parts of the country, very small
isolated populations remain in Dak Lak, Nghe An, Quang Nam, Dong Nai, and Ha
Tinh Provinces.
In China, Asian elephants once ranged widely over much of southern China,
including the Fujiang, Guangdong, and Guangxi Provinces (Smith and MacKinnon, in
press). The species was extirpated in southern Fujiang and northern Guangdong
during the 12th century, but evidence indicates persistence in Guanxi into the
17th century (Smith and MacKinnon, in press). All that now remains of this once
widespread elephant population in China is the remnant in Yunnan where the
species survives in three prefectures: Xishuangbanna, Simao, and Lincang.
In Peninsular Malaysia, the species is still widely distributed in the interior
of the country in the following States: Pahang (which probably has the largest
population), Perak, Johor, Kelantan, Terengganu, Kedah, and Negeri Sembilan
(where very few animals remain).
On Borneo, elephants only occur in the lowlands of the north-eastern part of the
island in the Malaysian State of Sabah and adjacent parts of Kalimantan
(Indonesia). In Sabah, they occur in forested areas in the south, centre, and
east of the State in the following Districts: Kinabatangan, Sandakan, Beluran,
Lahad Datu, Tawau, and Pensiangan. In Kalimantan, elephants occur only in the
Upper Sembakung River in Tindung District. The origin of the elephants of Borneo
remains unclear and the subject of debate. Due to the limited distribution of
the island’s elephant population it is argued by some that the species was not
indigenous, but descended from imported captive elephants (Medway 1977;
Cranbrook et al., 2008). However, others argues that while captive elephants
have undoubtedly been brought to Borneo, genetic analyses have shown that the
elephants found on Borneo are genetically distinct, with molecular divergence
indicating a Pleistocene colonization and subsequent isolation (Fernando et al.,
2003)
On Sumatra (in Indonesia), the elephant was once widespread, but now survives
only in highly fragmented populations. In the mid-1980s, 44 discrete elephant
populations were known to exist in Sumatra’s eight provinces, 12 of these were
in Lampung Province (Blouch and Haryanto, 1984; Blouch and Simbolon, 1985).
However, by 2003, only three of Lampung’s 12 populations were extant (Hedges et
al., 2005). An unknown number of Sumatra’s other elephant populations remain
(Blake and Hedges, 2004), and those that do are threatened by habitat loss,
poaching, and as a result of conflict with humans (Santiapillai and Jackson,
1990; Hedges et al., 2005). Nevertheless, the island is thought to hold some of
the most significant populations outside of India. For example, recent surveys
in Lampung Province’s two national parks, Bukit Barisan Selatan and Way Kambas,
produced population estimates of 498 (95% CI=[373, 666]) and 180 (95% CI=[144,
225]) elephants, respectively (Hedges et al., 2005). Bukit Barisan Selatan NP is
therefore a critically important area for Asian elephant conservation. The
challenge now is to protect these populations from further habitat loss and
poaching.
Countries: Native:
Bangladesh; Bhutan; Cambodia; China; India; Indonesia (Kalimantan, Sumatera);
Lao People's Democratic Republic; Malaysia (Peninsular Malaysia, Sabah);
Myanmar; Nepal; Sri Lanka; Thailand; Vietnam
Regionally extinct:
Pakistan
Population:
A recent estimate for the global population size of the Asian
elephant was 41,410–52,345 animals Sukumar (2003) The estimated population size
for each country was: Bangladesh 150–250; Bhutan 250–500; Cambodia 250–600;
China 200–250; India 26,390–30,770; Indonesia 2,400–3,400; Lao PDR 500–1,000;
Malaysia 2,100–3,100; Myanmar 4,000–5,000; Nepal 100–125; Sri Lanka 2,500–4,000;
Thailand 2,500–3,200; and Vietnam 70–150 (Sukumar, 2003) . However, Blake
and Hedges (2004) and Hedges (2006) argue that the oft-repeated global
population ‘estimate’ of about 40,000 to 50,000 Asian elephants is no more than
a crude guess, which has been accepted unchanged for a quarter of a century.
They argue that with very few exceptions all we really know about the status of
Asian elephants is the location of some (probably most) populations, with in
some cases a crude idea of relative abundance; and for some large parts of the
species range we do not even know where the populations are, or indeed if they
are still extant. These difference of opinion are due in part to the difficulty
in counting elephants in dense vegetation in difficult terrain, different survey
techniques being used in different places, and a too-widely held belief that
population monitoring is unimportant. Nevertheless, whatever the error margins,
it appears almost certain that over 50% of the remaining wild Asian elephants
occur in India.
The overall population trend of the Asian elephant has been downwards, probably
for centuries. This remains the case in most parts of its range, but especially
in most of the countries of South-east Asia. Within India, there is evidence
that the large population in the Western Ghats in south of the country has been
increasing in recent years due to improved conservation effectiveness.
Population Trend: Decreasing
Habitat
Asian elephants inhabit a wide range of grasslands and forest types,
including scrub forest, rainforest and semi-cultivated forests, preferring areas
that combine grass with low woody plants and trees.
Ecology and Biology.
Elephants are highly intelligent and long-lived animals; Asian elephants may
live as long as 70 years, in captivity. They are extremely sociable and occur in
groups of related females, led by the oldest female known as the 'matriarch'.
Groups of Asian elephants average six to seven individuals, and will
occasionally join with other groups to form herds; although these are more
transient than those of African savannah elephants. Males leave their natal
group when then reach sexual maturity at around six to seven years of age, after
which time they are predominantly solitary. When males reach 20 years old they
start coming into 'musth', an extreme state of arousal when levels of
testosterone in the blood may increase 20 times. This state lasts about three
weeks and during this time the individual will become aggressive and wander
widely in search of females. Musth may cause males to fight for access to
females and also increases their attractiveness to females. Cows only reach
sexual maturity at ten years of age, and the interval between births may be as
long as four years owing to the long gestation time and infant dependency. The
single calf may suckle from other females in the group as well as their own
mother.
Elephants use their dextrous trunk to pluck at grasses and pass them into their
mouths; the average daily intake of food is 150 kilograms of vegetation a day.
Grasses make up the mainstay of the Asian elephant's diet but scrub and bark are
also eaten, and calves may eat their mothers dung to obtain nutrients. Consuming
such large quantities of vegetation each day mean that Asian elephants
substantially alter their ecosystem by creating new habitats for emergent
vegetation. They also defecate up to 18 times per day, which has an important
role in dispersing the seeds of many plant species. Where elephants occur near
plantations they will readily feed on banana or rice crops. Asian elephants have
had a close relationship with man over the centuries; they are still used to
clear timber particularly in some of the more inaccessible forests of the
continent, and play an important role in the religious and cultural history of
the region. Adult females and calves may move about together as groups but adult
males disperse from their mothers upon reaching adolescence. Bull elephants may
be solitary or form temporary 'bachelor groups.
Cow-calf unit sizes generally tend to be small, typically consisting of 3 adult
females who are most likely related, and their offspring; however, larger groups
containing as many as 15 adult females may occur. There can also be seasonal
aggregations containing over 100 individuals at a time, including calves and
sub-adults. Until recently it was thought that Asian elephants, like African
elephants, typically follow the leadership of older adult females, or
matriarchs. But recently it has been shown that females can form extensive and
very fluid social networks, with a lot of individual variation in the degree of
gregariousness. Social ties generally tend to be weaker than in African
elephants.
Elephants are crepuscular. They are mega herbivores and consume up to 150 kg
(330 lb) of plant matter per day. They are generalist feeders, and both grazers
and browsers, and were recorded to feed on 112 different plant species, most
commonly of the order Malvales, and the legume, palm, sedge and true grass
families. They browse more in the dry season with bark constituting a major part
of their diet in the cool part of that season.
They drink at least once a day and are never far from a permanent source of
fresh water. They need 80–200 litres of water a day and use even more for
bathing. At times they scrape the soil for clay or minerals.
Elephants are able to distinguish low amplitude sounds. They use infrasound to
communicate; this was first noted by the Indian naturalist M. Krishnan and later
studied by Katharine Payne.
A healthy adult Asian elephant is not known to have natural predators, but there
have been rare instances of tigers preying on young or weak elephants. Bulls
will fight one another to get access to estrus females. Strong fights over
access to females are extremely rare. Bulls reach sexual maturity around the age
of 12–15. Between the age of 10 to 20 years, bulls undergo an annual phenomenon
known as "musth". This is a period where the testosterone level is up to 100
times greater than non-musth periods, and they become extremely aggressive.
Secretions containing pheromones occur during this period, from the paired
temporal glands located on the head between the lateral edge of the eye and the
base of the ear.
The gestation period is 18–22 months, and the female gives birth to one calf, or
occasionally twins. The calf is fully developed by the 19th month but stays in
the womb to grow so that it can reach its mother to feed. At birth, the calf
weighs about 100 kg (220 lb), and is suckled for up to 2–3 years. Once a female
gives birth, she usually does not breed again until the first calf is weaned,
resulting in a 4–5-year birth interval. Females stay on with the herd, but
mature males are chased away
Elephants' life expectancy have been exaggerated in the past; they live on
average for 60 years in the wild and 80 in captivity.
Females produce sex pheromones; a principal component thereof,
(Z)-7-dodecen-1-yl acetate, has also been found to be a sex pheromone in
numerous species of insects.
Intelligence
Asian elephants are highly intelligent and self-aware. They have a
very large and highly convoluted neocortex, a trait also shared by humans, apes
and certain dolphin species. Asian elephants have the greatest volume of
cerebral cortex available for cognitive processing of all existing land animals.
Elephants have a volume of cerebral cortex available for cognitive processing
that exceeds that of any primate species, and extensive studies place elephants
in the category of great apes in terms of cognitive abilities for tool use and
tool making. Elephants are reported to go to safer ground during natural
disasters like tsunamis and earthquakes, although there have been no scientific
records of this.
Threats
Numbers of Asian elephants were decimated by habitat loss and hunting throughout
their historical range. Vast tracts of land have been logged or simply cleared
to accommodate the growing human population in the region. Such disturbance from
infrastructure development can also cause increased stress and confusion amongst
elephants. Elephant populations have become increasingly isolated in the
fragmented habitat that remains, often coming into conflict with local farmers.
Crops are damaged and lives lost; up to 300 people a year are killed by
elephants in India, leading to retaliation on local elephants. Poaching for
ivory is also a threat and because only males have tusks, populations can become
extremely skewed towards females, thus affecting breeding rates.
Major Threat(s):
The pre-eminent threats to the Asian elephant today are
habitat loss, degradation, and fragmentation (Leimgruber et al., 2003; Sukumar,
2003; Hedges, 2006), which are driven by an expanding human population, and lead
in turn to increasing conflicts between humans and elephants when elephants eat
or trample crops. Hundreds of people and elephants are killed annually as a
result of such conflicts. The long-term future of elephants outside protected
areas, as well as in some protected areas, is therefore inextricably linked to
mitigating such human–elephant conflicts, and this is one of the largest
conservation challenges in Asia today (Sukumar, 1992, 2003; Hedges 2006).
Asian elephants live in the region of the world with the densest human
population, growing at a rate of between 1–3% per year. Because elephants
require much larger areas of natural habitat than most other terrestrial mammals
in Asia, they are one of the first species to suffer the consequences of habitat
fragmentation and destruction and because of its great size and large food
requirements, the elephant cannot co-exist with people in areas where
agriculture is the dominant form of land-use. In extreme cases, elephants have
been confined as so called ‘pocketed herds’ in small patches of forest in
landscapes dominated by man. Such ‘pocketed herds’ represent an extreme stage in
the human–elephant conflict (Olivier, 1978). In other cases elephants have been
caught and taken to so-called Elephant Training Centres where they languish,
lost to the wild population (Hedges et al., 2005, 2006).
Poaching is a major threat to elephants in Asia too, although reliable estimates
of the number of elephants killed and the quantities of ivory and other body
parts collected and traded are scarce (Sukumar et al., 1998; Milliken, 2005). It
has been argued that poaching is a relatively minor threat to Asian elephant
because some males and all females lack tusks (Dawson and Blackburn, 1991).
However, the reality is that elephants are poached for a variety of other
products (including meat and leather) in addition to ivory, and poaching is now
acknowledged as a threat to the long-term survival of some Asian elephant
populations (e.g. Kemf and Santiapillai, 2000; Menon, 2002). Moreover, poaching
of elephants for ivory is a serious problem in some parts of Asia (Sukumar,
1992; Menon et al., 1997). In Periyar Tiger Reserve in southern India, for
example, ivory poaching has dramatically skewed adult sex ratios: over the
20-year period from 1969 to 1989 the adult male: female sex ratio changed from
1:6 to 1:122 (Chandran, 1990). Selective removal of tusked males has several
implications for the affected populations: sex ratios obviously become highly
female biased, genetic variation is reduced, and fecundity and recruitment may
decline (Sukumar et al., 1998; Sukumar, 2003). Poaching of elephants is also a
major problem in other parts of Asia. Large-scale hunting of elephants for
ivory, bush meat, hides, and other products has reduced their populations
significantly over a wide area from Myanmar to Indonesia (Menon et al., 1997;
Duckworth and Hedges, 1998; Kemf and Santiapillai, 2000; Martin and Stiles,
2002; Menon, 2002; World Wide Fund for Nature, 2002a; Hedges et al., 2005).
Conservation Actions:
This species is listed on CITES Appendix I. The most important conservation priorities for the Asian elephant are: 1) conservation of the elephant's habitat and maintaining habitat connectivity by securing corridors; 2) the management of human–elephant conflicts as part of an integrated land-use policy that recognizes elephants as economic assets from which local people need to benefit or at least no suffer; 3) better protection to the species through improved legislation and law enforcement, improved and enhanced field patrolling, and regulating/curbing trade in ivory and other elephant products. Monitoring of conservation interventions is also needed to assess the success or failure of the interventions so that adjustments can be made as necessary (i.e. adaptive management). Reliable estimation of population size and trends will be needed as part of this monitoring and adaptive management approach.