The tiger is the largest member of the cat family, with the
Amur (Siberian) tiger weighing as much as 360 kg (790 lb). Although it is found
in a variety of habitats, the tiger always requires dense vegetative cover, an
adequate supply of large ungulate prey, and access to a reliable source of
water. The principal prey of the tiger consists of various species of deer and
wild pigs, usually in the 50 - 200 kg (110 - 440 lb) range. These include
sambar, chital, swamp deer, red deer,
rusa deer and wild boar. It will also take young elephants and rhinos and
smaller species such as monkeys, birds, reptiles and fish.
Tigers are generally diurnal or crepuscular where they are
undisturbed, but they become nocturnal in disturbed habitats or near human
settlements. They do not readily cross large open areas. Although tigers are
usually solitary (except for females with cubs), males and females exhibit a
high degree of social tolerance towards one another. A male tiger usually
establishes a territory that does not overlap with the territories of other
males but does overlap the territories of 2 - 3 females (up to 7). Females
establish territories that generally (but not always) do not overlap each
other. The range of an individual tiger can vary from 50 sq km (20 sq mi) in an
area with high prey densities (e.g. some reserves in India)
to 4000 sq km (1500 sq mi) in Siberia.
The tiger formerly occurred from Turkeyacross southern Asia and most of China,
to the Soviet Far East. The Southeast Asian range included peninsular Malaysia,Singapore, Sumatra,
Java and Bali. But the abundance and distribution of
tigers has diminished substantially since the beginning of the 20th century. 3
of the 8 subspecies of tiger, the Bali, Caspian and
Javan tigers, have become extinct since the 1950's. Currently, the tiger occurs
only in scattered populations from Indiato Vietnam and
in Indonesia (Sumatra),
the Russian Far East, and possibly in Chinaand North Korea.
The tiger is extinct in most of its former range.
Commercial poaching (especially to obtain various parts of
the tiger's body for Oriental medicine), a declining prey base, and loss of
habitat are the principal threats to the tiger at present.
Tidbits
*** In Malaysia,
until the late 1950's, the tiger had a status lower than that of the wild pig,
rat or squirrel. It was to be destroyed on sight by every possible means due to
its perceived threat. (Khan 1987)
*** In Nepal,
many villagers don't understand why the law protects animals such as tigers
(and rhinos and snow leopards), which they consider to be pests to their crops
and livestock, particularly since no one uses them for food or other purposes.
The villagers believe that their lives and the welfare of their families are
more important than "saving wildlife." (Mishra et al. 1987)
*** Some cultures (e.g. in Indiaand Bangladesh)
tolerate the killing of people by tigers to an extent. In fact, the tiger is
the national animal of Bangladesh(and India).
This is despite the fact that between 1948 and 1986, 814 people were killed by
tigers in Bangladesh's
Sundarbans (Luoma 1987).
*** The use of infra-red cameras to survey nocturnal animals
has been applied in the KerinciSeblatNational Park in Sumatra,
Indonesia. In six weeks
of photo-trapping, nine individual tigers were photographed.Surprisingly, these tigers were not in remote
forest but on the edge of the park, close to villages and a major logging
operation. (Martyr 1997)
*** In a landmark case, four farmers in China’sJilinProvincereceived compensation for three cows killed and eaten by an Amur (Siberian)
tiger. They won a lawsuit against the local government, which paid out in
accordance with a provincial law, passed in 1996, that compensation would be
paid to those whose crops or domestic animals were damaged by wild animals. One
of the farmers, Li Yi, said he was glad tigers had protection, but people’s
interests must be guaranteed at the same time. (Cat News 1998d)
*** [Editor's Note: Do not try this at home!] While sleeping
in their hut, an Indian farmer, his wife and three children awoke to find a
tiger sleeping with them. The tiger was "sleeping like a baby." The
family crept out quietly without waking the tiger. They contacted local Forest
Department officials, who tranquilized the tiger and released it in the forest.
(Cat News 2002a)
*** Tigers can adapt themselves to a great variety of
situations, including some contact with humans, as long as their prey base
remains ample - about 50 deer-size animals to support one tiger during a year
(U. Karanth, cited in Simmons 2003).
2004: Occurs in Bangladesh,Bhutan, Cambodia,China, India,Indonesia (Sumatra),Laos, Malaysia,Myanmar, Nepal,
North Korea, Russia,Thailand, and Vietnam(IUCN 2004).
Taxonomy:
Recent genetic analyses have lead to the proposal that all
modern cats can be placed into eight lineages which originated between 6.2 -
10.8 million years ago. The tiger is placed in the "Panthera
lineage," which diverged from its ancestors as a separate lineage 10.8
million years ago. The Panthera lineage also includes the lion, the jaguar, the
leopard, the clouded leopard, and the snow leopard. (Johnson et al. 2006)
Population Estimates:
* World
* By
Subspecies
* By Country
[Note: Figures
given are for wild populations only.]
o 2000: Perhaps 350 adults (Miquelle, D.,
quoted in Wildl. Cons. 2000b)
o 2004: 450
(Oryx 2004b)
* South China (Amoy)
Tiger (Panthera tigris amoyensis)
o Early
1950's: 4000 (Nowell & Jackson 1996)
o 1982: 150
- 200 (Tilson et al. 1997)
o 1986: 30 -
80 (Jackson 1993)
o 1989: 30 -
50 (Oryx 1989h)
o 1995:
"An unconfirmed report in 1995 from the Chinese Ministry of Forestry
suggested that 6 - 13 tigers remain in Jiangxi Province with another 4 - 5
tigers in Fujian, Guangdong and Hunan Provinces - a total of fewer than 20
(Tilson et al. 1997).
o 1996: 20 -
30 (Jackson 1996)
o 1998: 20 -
30 (Jackson 1998)
o 2004:
Possibly extinct in the wild (Tilson et al. 2004)
o 1987:
Probably still about 350 (Tilson & Seal 1987)
o 1993: 300
- 479 (Jackson 1993)
o 1994: 300
- 460 (Jackson 1994)
o 1996: 300
- 460 (Jackson 1996)
o 1998: 362
(Jackson 1998)
* Bhutan
o 1993: 20 -
50 (Jackson 1993)
o 1994: 50 -
240 (Jackson 1994)
o 2000: 115
- 150 (Focus 2000a)
* Cambodia
o 1994: 100
- 200 (Jackson 1994)
o 1996: 100
- 200 (Jackson 1996)
o 1998: 150
- 300 (Jackson 1998)
* China
o Late
1940's: 4000 (South China tiger) (Jackson1993)
o 1972: Not
more than 50 (Amur tiger) (Curry-Lindahl 1972)
o 1986: 30 -
80 (South China Tiger) (Jackson1994)
o 1994: No
more than 20 (Siberian tiger) (Anon. 1994e)
o 1997: 92 -
117 (Bengal tiger: 30 - 35; Indo-Chinese tiger: 30 - 40;South China tiger: 20 - 30; Amur tiger: 12) (Ma et al.
1997)
o 1998: 110
- 140 (Bengal tiger: 30 - 35; Indo-Chinese tiger: 30 -
40; South China tiger: 20 - 30; Amur tiger: 30 - 35) (Jackson1998)
* India
o 1900: 20,000 - 40,000 (Tilson & Seal
1987)
o 1914:
Possibly 40,000 (Gee 1964)
o 1964: Not
more than 4000 (Gee 1964)
o 1969: 2724
- 3700 (Curry-Lindahl 1972)
o 1970: 1644
- 2010 (Mountfort 1983)
o 1971: 1960
(Curry-Lindahl 1972)
o 1972: At
least 1800 (Tilson & Seal 1987)
o 1972:
Fewer than 2000 (Nowell & Jackson 1996)
o 1979: 2484
(Oryx 1979b)
o 1984:
About 4000 (Oryx 1991f)
o 1987:
About 4000 (Tilson & Seal 1987)
o 1989: 4334
(Nowell & Jackson 1996)
o 1993: 2500
- 4500 (Jackson 1993)
o 1994: 2750
- 3750 (Jackson 1994)
o 1996: 2500
- 3750 (Jackson 1996)
o 2003: 1800
- 2000 (Thapar 2003)
"Most people have the absurd notion
that one can go out and count every individual tiger and deer in this huge
country [India].I have to be blunt with my trainees and tell
them the so-called censuses of the past were practically worthless, and the numbers
of tigers they read about in the press are absurd." (Karanth 1999)
The tiger formerly occurred from Turkeyacross southern Asia (except Sri
Lanka), most of China(including Hong Kong), to the Soviet Far East (includingSakhalinIsland).
The Southeast Asian range included peninsular Malaysia,Singapore, Sumatra,
Java and Bali. But the abundance and distribution of
tigers has diminished substantially since the beginning of the 20th century. 3
of the 8 subspecies of tiger, the Bali, Caspian and
Javan tigers, have become extinct since the 1950's. The tiger is now extinct in
most of its former range. As of 1996, the tiger occurred only in scattered
populations from Indiato Vietnam and
in Sumatra (Indonesia),China and the
Russian Far East. By 2001, no subpopulation was believed to contain more than
250 mature breeding individuals (IUCN 2003a).
The Amur (Siberian) tiger ranged throughout the forests of Koreaand China,
north along the eastern coast of Russia,
to the edge of Siberia. But in the late 19th century,
during the construction of the Chinese Eastern Railway, and the ensuing influx
of Russian settlers to the Far East, Siberian tigers
were deliberately eradicated. In the early 1940's the Amur tiger survived in
only about five isolated areas in Primorye (MaritimeTerritory), Russia.
However, protected effectively by law in Russiasince the 1950's, the Siberian tiger recovered significantly, and by 1980 it
had recolonized many of the regions where it occurred in the early 20th
century.
The historical range of South Chinatigers stretched over a vast landscape of 2000 km (1200 mi) from east to west
and 1500 km (930 mi) from north to south in China.
From east to west it ranged from Jiangxiand ZhejiangProvincesthrough Guizhou and SichuanProvinces, and from north to south
it ranged from the QinlingMountainsand Yellow River area to Guangdong,
Guangxi and YunnanProvinces(Tilson et al. 2004). Surveys conducted in the 1990's found evidence of the
presence of four subspecies of tigers in Yunnan,Guangxi, Guangdong,Jiangxi, Hunan,Guizhou, Sichuan,
and HeilongjiangProvinces.
And, after an absence of more than 40 years, it has been reported that tigers
spotted in ZhejiangProvincehave been confirmed by DNA tests of feces, carried out by scientists from ZhejiangUniversity, to be South
China tigers (Anon. 2000). However, in 2001-2, Chinese-American
field surveys of 8 reserves in five Chinese provinces identified by government
authorities as habitat most likely to contain tigers found no evidence of wild
South China tigers, few prey species, and no livestock depredation by tigers reported
in the last 10 years (Tilson et al. 2004).
Commercial poaching (especially to obtain various parts of
the tiger's body for Oriental medicine), a declining prey base, and loss of
habitat are the principal threats to the tiger at present.
The Amur tiger in Russiahas come under increased poaching pressure in recent years due to the political
and economic changes that have occurred subsequent to the breakup of the Soviet
Union.
In India,
thousands of villagers enter forests around their homes, including tiger
reserves, to shoot and trap the tigers' prey. This can reduce the prey
densities to levels below what is needed to support viable tiger populations.
The extirpation of tigers on Bali and Java was attributed to
extensive habitat fragmentation, widespread loss of critical ungulate prey
through disease, and direct mortality by man, partly as a result of civil
unrest in the 1960's (armed groups seeking the sanctuary provided by tiger
reserves killed the tigers) (Seidensticker 1986).
More so in the past than at present, tigers were killed
because they were considered to be a threat to human life and domestic
livestock. They were also valued as a big game trophy by sport hunters. Some
European hunters and Indian maharajahs each killed hundreds of tigers.
Data on Biology and Ecology
Weight:
Amur (Siberian)
tigers may weigh as much as 360 kg (790 lb). In India,
male Bengal tigers usually weigh 200-270 kg (440 - 595
lb). Male Sumatran tigers weigh 100 - 140 kg (220 - 310 lb).
Habitat:
The tiger is found
in a variety of habitats: from the tropical evergreen and deciduous forests of
southern Asia to the coniferous, scrub oak, and birch
woodlands of Siberia. It also thrives in the mangrove
forest of the Sundarbans, the dry thorn forests of north-western India,
and the tall grasses of the terai at the foot of the Himalayas.
Tigers are found in Himalayan valleys, and a Bengaltiger has been photographed at 3,000 m (9800') in the Himalayas.
The extinct Caspian tiger frequented seasonally flooded riverine land known as
tugai, consisting of trees, shrubs, and dense stands of tall reeds and grass up
to 6 m (20') in height. (IUCN 2004)
Its broad
geographical distribution creates the illusion that the tiger is an adaptable
species. In fact, it is a highly specialized large predator with specific
habitat requirements and is much less adaptable than, say, the leopard.
(Macdonald 1984) The main habitat requirements of the tiger are dense
vegetative cover, an adequate supply of large ungulate prey (principally deer
and wild pigs), and access to a reliable source of water.
The tiger lives in
both the Himalaya, Indo-Burma, Sundaland, and Western Ghats and Sri Lanka
Biodiversity Hotspots (Cons. Intl. 2005) as well as the Annamite Range Moist
Forests, Sundarbans Mangroves, Kayah-Karan/Tenasserim Moist Forests, Sundaland
& Eastern Indonesian Archipelago Mangroves, Terai-Duar Savannas &
Grasslands, Sumatran Montane Forests, Western Ghats Moist Forests, Eastern
Indochina Dry & Monsoon Forests, Eastern Indian Monsoon Forests, Northern
Indochina Subtropical Moist Forests, Russian Far East Temperate Forests,
Sumatran-Nicobar Islands Lowland Forests, and Peninsular Malaysian Lowland
& Montane Forests Global 200 Ecoregions (Olson & Dinerstein 1998, Olson
& Dinerstein 1999).
Age to Maturity:
Average - 3.4
years (female), 4.8 years (male) (Chitwan, Nepal)
(Smith & McDougal 1991)
Gestation Period:
102 - 103 days.
Birth Season:
Mating takes place
throughout the year, but is most frequent from November to April. In Nepal,
a peak in births occurs from May - July.
Birth Rate:
In Chitwan (Nepal),
the average litter size was 3.0 (range 2 - 5). Generally 2 - 3 in a litter are
most common, with a range of 1 - 7.
The time between
births is usually 20 - 30 months. If the young are lost soon after birth the
interval can be as short as 8 months.
The average
reproductive life span of Chitwan (Nepal)
tigers was found to be 6.1 years for females and 2.8 years for males. For
females, the mean number of cubs surviving to dispersal was estimated at 4.54
(Variance = 11.48) and the average number of cubs incorporated into the
breeding population was 2.0 (Variance = 3.26). For males, an average of 5.83
cubs survived to dispersal (Variance = 50.0), and 2.0 were incorporated into
the breeding population (Variance = 7.0). (Smith & McDougal 1991)
The reproduction
rate for Amur [Siberian] tigers appears to be approximately 1 cub/adult
female/year (Stamotyuk 1998).
Early Development:
Cubs are dependent
on their mother's milk for about the first 2 months of their lives, and after
that the female starts to take them to kills. Weaning takes place at about 6
months. A cub is totally dependent on its mother for food until it is about 18
months old.
Dispersal:
Dispersal usually
occurs at an age between 18 and 28 months for male and female young. This is
about 2 - 3 months after a new litter is born, which coincides with the time
when the new litter begins to follow the mother.
The process of
dispersal may take a month or more and usually involves several exploratory
trips. A young male seeks a territory far from his birth site but may later
return. Some young females never leave their mother's territory and may
eventually force their mother out. The average dispersal distance for 10 young
males in ChitwanNational
Park (Nepal)
was 33 km (20 mi); for 4 females it was shorter, less than 10 km (6 mi),
because of the female's tendency to settle next to its mother's territory
(Seidensticker & Lumpkin 1991).
Maximum Reproductive
Age:
At least 14 years
(captivity).
Maximum Age:
A female tiger may
live to about 15 years in the wild. In captivity it can live as long as 26
years.
Diet:
The principal prey
of the tiger consists of various species of deer and wild pigs, usually in the
50 - 200 kg (110 - 440 lb) range. These include sambar, chital, swamp deer, red
deer, rusa deer and wild boar. It will also take young
elephants and rhinos and smaller species such as monkeys, birds, reptiles and
fish. Tigers sometimes prey on leopards and other carnivores such as bears,
which they attack in their winter dens. They eat carrion and can be
cannibalistic.
In Indiathe gaur is sometimes the main prey, including bulls weighing up to 1000 kg
(2200 lb). In Thailand, barking deer was the major prey species, while
important secondary prey included wild boar, sambar deer, the crestless
Himalayan porcupine and hog badger (Rabinowitz 1989).
The average amount
eaten over several days is about 15 - 18 kg/day (33 - 40 lb/day) (Macdonald
1984).
Behavior:
Tigers are
generally diurnal or crepuscular where they are undisturbed, but they become
nocturnal in disturbed habitats or near human settlements.
A tigress with
young has to kill more often to provide food - an estimated once every 5 - 6
days, or 60 - 70 animals/year, for a female with 2 young, compared with a kill
every 8 days or 40 - 50 kills/year for a female in the same area without
dependent young (Macdonald 1984). Tigers travel extensively in search of prey,
often covering 8 - 24 km (5 - 15 mi) in the course of an unsuccessful night of
hunting (Seidensticker & Lumpkin 1991).
Births can occur
in a cave, a rocky crevice or dense vegetation.
Tigers do not
readily cross large open areas. They readily enter water, even swimming across
wide rivers and lying half-submerged in lakes or ponds during hot weather.
Tigers are
successful in approximately 5 - 10% of their attacks on prey.
Social Organization:
Although tigers
are usually solitary (except for females with cubs), males and females exhibit
a high degree of social tolerance towards one another. Males associate with
females for breeding and have been observed with females and cubs when feeding
or resting. On the other hand, because tigers usually live in dense cover,
where small- to medium-sized prey are scattered and hard to find, it is
probably more efficient to hunt separately than in groups as lions do.
A male tiger usually
establishes a territory that does not overlap with the territories of other
males but does overlap the territories of 2 - 3 females (up to 7). Females
establish territories that generally but not always do not overlap each other.
If the territories of females do overlap, the females generally concentrate
their activities in different areas so that they are rarely in the same area at
the same time.
Male and female
tigers leave scent marks such as urine sprayed on bushes and trees, feces left
in prominent places, scratch marks on trees, and scrapes on the ground to show
that their territory is occupied. This generally helps tigers avoid one
another, so that fights are not frequent, although they do occur.
Age and Gender
Distribution:
The male/female
ratio is not significantly different from unity at birth. The ratio of adults
in the wild is approximately 1 male to 2 females (Spitsin et al. 1987, Smith
& McDougal 1991).
Mortality and
Survival:
In Chitwan (Nepal),
mortality during the first year was 34%. Second-year mortality was 17%.
Mortality was estimated to be 0.34 for males and 0.43 for females during the
period between dispersal and establishment of a breeding territory. (Smith
& McDougal 1991)
Temporal
variability in cub survival ranged from 90% survival to dispersal in a year
when resident males were stable, to 33% survival in a year when infanticide was
widespread. During the latter period, which followed the death of a male whose
territory included 7 females, a number of instances of infanticide occurred as
new males took over the territories of former residents. (Smith & McDougal
1991)
About half of all
cubs do not survive more than 2 years (Nowak & Paradiso 1983).
[There is] an
annual loss of cubs [of Siberian tigers] in the range of 16 - 26% (Stamotyuk
1998).
Density and Range:
Density:
* 0.01 adult
tigers/sq km (0.03 adult tigers/sq mi) (Udjung Kulon Reserve, Java,
Indonesia) (Seidensticker
& Lumpkin 1991)
* Tigers have
higher densities if the availability of prey is higher. The following entries
are listed in decreasing order of the density of ungulate prey (Nowell &
Jackson 1996):
o 0.12
individuals/sq km (0.3 individua
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