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SPECIES PROFILE
Siberian Tiger
Panthera tigris altaica
Photo sourced from: https://en.wikipedia.org/wiki/Siberian_tiger#/media/File:Panthera_tigris_altaica_13__Buffalo_Zoo.jpg
January 2016
Elyshia Wignell BSc (Zoology)
Donna Cuttriss
This publication should be cited as:
Wignell, E. & Cuttriss, D. (2016) Species Profile: Siberian Tiger (Panthera tigris altaica). Zoodoo
Zoo. Richmond, Tasmania.
About this Pest Risk Assessment
This pest risk assessment is developed in accordance with the Policy and Procedures for the
Import, Movement and Keeping of Vertebrate Wildlife in Tasmania (DPIPWE 2011). The policy
and procedures set out conditions and restrictions of the importation of mammals, birds,
reptiles and amphibians pursuant to s34 of the Nature Conservation Act 2002. This pest risk
assessment is prepared by Zoodoo Zoo for the use within the Department of Primary Industries,
Water and Environment, Tasmania.
For more information about this Pest Risk Assessment, please contact:
Elyshia Wignell
Zoodoo Zoo Pty Ltd
Address: 620 Middle Tea Tree Road, RICHMOND Tasmania, 7025
Phone: (03) 6260 2456
Email: [email protected]
Visit: www.zoodoo.com.au
Disclaimer
The information provided in this Pest Risk Assessment is provided in good faith. Zoodoo Zoo
and its employees do not accept liability however arising, including liability for negligence,
for any loss resulting from the reliance upon the information in this Pest Risk Assessment.
1. Summary
The Siberian tiger (Panthera tigris altaica) is one of the 7 listed sub-species of tiger and is
the largest, and most northernmost, of the 5 remaining sub-species. Their historical native
range covers up to 300,000km² (Tian et al. 2011) and includes far south-eastern Russia,
northern China and east Mongolia, the Korean peninsula and extends as far as the Sea of
Japan (Tian et al. 2011; Alasaad et al. 2011).
No feral populations of Siberian tigers have ever been known to establish and the preferred
habitat type for Siberian tigers includes areas with monsoonal climates and Korean pine
forests.Therefore, this species is considered to be highly unlikely to be able to establish
populations in Tasmania.
The Siberian tiger is listed as ‘Endangered’ by the IUCN, due to poaching, habitat loss and
degradation, as well as having a scarce prey source due to overhunting by humans.
In Tasmania, the Siberian tiger is likely to be categorised as a ‘controlled animal’ under the
Nature Conservation Act 2002.
The Vertebrate Pest Committee (VPC 2007) has assessed the Siberian tiger as an ‘extreme’
threat species. Therefore, collections of this species may only be kept under permit for
either education, conservation, entertainment and/or exhibition purposes (VPC 2007).
2.
Introduction
2.1 NAME AND TAXONOMY
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Felidae
Genus: Panthera
Species: Panthera tigris altaica
Sub-species: Other tiger Sub-species include: Bengal Tiger (Panthera tigris tigris),
Indochinese Tiger (Panthera tigris corbett), South China Tiger (Panthera tigris amoyensis),
Sumatran Tiger (Panthera tigris sumatrae), Javan Tiger (Panthera tigris sondaica), Bali Tiger
(Panthera tigris balica) and the Caspian Tiger (Panthera tigris virgata). However, the Javan,
Bali and Caspian Tigers are all declared extinct (Dybas 2011; IUCN 2011).
Common names: Siberian tiger and Amur tiger
Known hybrids: It is possible for lions and tigers to mate and create hybrids and there are
two kinds of lion/tiger hybrids. If a female lion is mated with a male tiger the hybrid is
known as a ‘Tigon’, however if a female tiger is crossed with a male lion the hybrid is
referred to as a ‘Liger’. Both types of hybrids create offspring that grow to be considerably
larger than either of their parents and male offspring are always sterile. Most female
offspring are also sterile, however a small percentage are able to breed and when such
breeding occurs her offspring are then referred to as either li-ligers or ti-tigons (Baker
2006).
2.2 DESCRIPTION
Genetic analysis shows that the Siberian tiger has the lowest genetic diversity of all the
remaining sub-species (Alasaad, Soriguer, Chelomina, Petrovich Sushitsky and Fickel 2011).
Furthermore, the Siberian tiger is the largest, heaviest and most northernmost of the
remaining sub-species (Tian, Wu, Smith, Wang, Kou and Ge 2011; Song, Hua, Song and
Zhang 2007). Male and female Siberian tigers can weigh up to 320kg and 160kg,
respectively, and have a head-tail length of 3.3m for males and 2.6m for females (Baker
2006 & 18). Additionally, Siberian tigers have the least amount of stripes (after the South
China tigers) (Tilson 2016), are thought to have lighter and less dense stripe patterns and a
coat length much longer than that of the other sub-species, ranging between 40-105mm in
length, compared to a length of between 7 and 35mm for all other tigers (Baker 2006). Such
differences in stripes, size, weight and coat length are all due to the much harsher and
colder conditions experienced in the home ranges of the Siberian tiger (Baker 2006; Kerley
et al. 2003).
2.3 CONSERVATION AND LEGAL STATUS
CONSERVATION
The Siberian tiger is currently listed as ‘Endangered’ by the ICUN, since it was downgraded
from its ‘critically endangered’ listing in 2008 (IUCN 2011). There is thought to be less than
400 individuals remaining throughout the entire world (Fukui et al. 2013).
LEGAL STATUS
In Tasmania, the Siberian tiger is a ‘controlled animal’ under the Nature Conservation Act
2002.
The Vertebrate Pest Committee (VPC 2007) has assessed the Siberian tiger as an ‘extreme’
threat species. Therefore, collections of this species may only be kept under permit for
either education, conservation, entertainment and/or exhibition purposes (VPC 2007).
This species is listed under CITES Appendix I (Liu et al. 2014).
3.
BIOLOGY AND ECOLOGY
3.1 LIFE HISTORY
Unlike most tiger sub-species Siberian tigers are thought to be seasonal breeders, most
likely due to the harsh environmental conditions they face in their wild habitat (Kerley,
Goodrich, Miquelle, Smirnov, Quigley and Hornocker 2003). It is estimated that most
Siberian tiger young are conceived between March and May (however, it has been
demonstrated to be as early as January and February) (Kerley et al. 2003), which
corresponds with Siberian tiger births occurring most often between August and October
(Kerley et al. 2003). A 7-8 month period of anoestrous is not uncommon for Siberian tigers,
however would be extremely unusual for all other tiger sub-species who are capable of
ovulating all year round (Tilson 2016).
As tigers are solitary animals, individuals use scent markings as a way of finding each other
when it is time for mating (Tilson 2016). The males’ ability to find the female based on her
scent markings is extremely important, as females are only receptive for approximately 2-3
days of their entire oestrus cycle (Baker 2006). To further complicate things for the male,
Siberian tigers are induced ovulators and therefore they must receive a certain amount of
copulations, during a particular time, in order for their ovulation to be stimulated (Tilson
2016).
To assist the males to ensure that they are present at the appropriate time, when they are
available for mating, females will begin scent marking much more frequently (Baker 2006).
Furthermore, males are also equipped with an unusual ‘cone-shaped’ penis that has a
‘baculum’ (bony-like structure) covered with over 100 backwards facing barbs, each of
these features assist the male with stimulating the female to ovulate (Baker 2006).
During oestrus females are characterised by behaviours such as, vocalisation, rolling on the
ground in front of males, as well as spitting and striking at males. Eventually, the female will
accept a male and allow him to get closer without aggression (Baker 2006). Once chosen,
tigers pair and will copulate up to 52 times a day (approximately 15 seconds each) for
approximately two days (sometimes up to 7), after which the male will leave (Tilson 2016).
Should copulation be unsuccessful, the female will return to oestrus 25- 30 days later and
the male will return to try again. During times when the female is sexually receptive, and
therefore is not raising cubs, she will continue to cycle every 25-30 days throughout the
breeding season (Tilson 2016).
During each oestrus, females may be stimulated by more than one male and therefore it is
possible to have cubs within a single litter who have been fathered by different males
(Baker 2006; Tilson 2016).
Gestation lasts between 102 and 105 days (Shoemaker, Maruska and Rockwell 1997) and
the female can have between 1 and 6 cubs, however the average litter size is often between
2 and 3 (Tilson 2016). Approximate birth interval between the first and last cub is between 2
and 4 hours (Tilson 2016).
At birth all cubs are blind and toothless (Tilson 2016). Eyes do not begin to open until
approximately 7 days old, however it can be up to 12 days, and their full set of milk teeth
have usually emerged by 1 month of age (Baker 2006). Solid food does not begin to be
eaten until between 6 and 8 weeks and their permanent canine teeth are not fully emerged
until between 16 and 18 months of age (Tilson 2016).
The birth weight of tiger cubs averages between 785 and 1610g (Baker 2006 & 18), but their
weight increases rapidly and by 6 months of age males and females weight around 40-50kg
and 26-36kg, respectively. Weight differences between the sexes only increase as they get
older, with males weighing up to 45kg more than females at around 18 months of age
(Baker 2006; Tilson 2016). Siberian tigers can continue to grow until they are up to 5 years
old, with slow growth being demonstrated more often in males than females (Baker 2006).
Average inter-birth interval for Siberian tigers is approximately 21.4 months, however
should the cubs die, females are capable of giving birth up to 3 times a year. Furthermore,
should a new male wish to mate with a female who has young cubs, it has been
demonstrated that this male will kill her cubs in order to stimulate her oestrus cycle and
therefore produce offspring of his own (Baker 2006).
The mortality rate of Siberian tiger young, in both the wild and captivity, is relatively high
with an estimated 40% mortality occurring within the first 2 months of life and
approximately only 1-2 young from each litter surviving to be past 2 years of age (Kerley et
al. 2003; Tilson 2016).
Over the lifetime of a tigress, it is estimated that between 13-18 young can be produced,
under ideal conditions. However, only around 50% of those young are likely to survive into
adulthood (Kerley et al. 2003).
There is much debate amongst scientists as to how quickly Siberian tigers are capable of
increasing their population numbers. For instance, some researchers believe that when
Siberian tigers are properly protected, and have access to an abundance of prey, they are
productive breeders and therefore allow for fast population growth (Miquelle, Smirnov,
Zaumyslova, Soutyrina and Johnson 2015). However, given that Siberian tigers are
demonstrated as having one of the latest ages at first birth and one of the longest interbirth intervals of all tiger sub-species, other researchers argue that the population growth
of Siberian tigers would be one of the slowest of all the large felids. More research needs to
be done in this area to determine which of these theories is likely to be the most accurate
(Miquelle et al. 2015).
Tigers are considered as being quite maternal species and it is estimated that approximately
70% of their day consists of nursing their newborns during the first 10 days, after this it
drops to approximately 60% until around 40 days when it drops again to approximately
30%. At three months of age the cubs begin to be weaned and the female only spends
approximately 10% of her day nursing (Baker 2006). In order to keep up with the feeding
demands of her cubs, the female must increase her killing rate by as much as 50%, and
therefore must spend significantly more time hunting when she has cubs. As a result,
females must be in a good condition prior to pregnancy in order to survive the demand
once her cubs are born (Baker 2006).
Although cubs are weaned between approximately 3 and 6 months of age, they will remain
with their mother until between 17 and 24 months of age, during which time she teaches
them appropriate social behaviours and how to hunt (Baker 2006). However, males tend to
become more independent than females and at 15 months of age it is not uncommon for
males to wander away from their mother for a few days at a time. Females will often create
their home territories next door, or in close proximity, to their mother’s territory, whereas
males will disperse much farther (Baker 2006).
Tigers become sexually mature between 3-4 years of age, however males often have to wait
longer to breed than females as they must fight other males to gain territories and
therefore to gain access to females (Baker 2006). Additionally, it is estimated that males will
cease breeding at a younger age than females. However, this is thought to be mainly due to
their reduced ability to hold territories as they get older, more-so than their inability to
copulate as males are thought to remain fertile for up to 14 years, compared to
approximately 12 years for females (Baker 2006).
Mortality amongst tigers significantly increases once they reach the age of 12 (Baker 2006;
Tilson 2016).
3.2 HABITAT REQUIREMENTS AND PREFERENCES
Siberian tigers are commonly found within northern and cold temperate zones where there
is a monsoon climate, characterised by winters that are cold and windy (Kerley et al. 2003)
and have between 75 and 85% of its precipitation occurring as rain between April and
November (Goodrich, Seryodkin, Miquelle and Bereznuk 2011; Tian et al. 2011). However,
slightly warmer and moister climates, such as the Sikhote-Alin mountains, may also be
home to Siberian tiger populations (Tian et al. 2011).
Siberian tigers can be found as high as 3000m, above sea level, within this area. However, it
is believed that latitudes above this height consist of climates that are too harsh and cold
for their survival. The habitat that appears to be favoured by Siberian tigers includes broadlevel, Korean pine forests of latitudes up to 3000m, as these are considered to be some of
the most diverse forests in the world (Tian et al. 2011; Alasaad et al. 2011). Habitats that
consist of deciduous, or coniferous mixed with deciduous, trees and that are highly forested
are by far the preferred habitat type of Siberian tigers (Miquelle, Rozhnov, Ermoshin,
Murzin, Nikilaev, Hernandez-Blanco and Naidenko 2015). Therefore, tigers will rarely be
found living in open habitats such as wetlands or agricultural fields (Baker 2006). On top of
their preference for monsoonal climates and Korean pine forests, Siberians tigers are also
thought to prefer habitats with lower human population densities (Alasaad et al. 2011).
Although there are approximately 17 patches of suitable habitat in Russia, spanned across
155, 000km², unfortunately only 2 of these patches are interconnected and therefore the
movement of tigers throughout each of these patches is extremely limited (Miquelle and
Rozhnov et al. 2015)
3.3 NATURAL GEOGRAPHIC RANGE
Historically, Siberian tigers had a distribution that covered up to 300,000km² (Tian et al.
2011) and included far south eastern Russia, northern China and east Mongolia, the Korean
peninsula and extended as far as the Sea of Japan (Tian et al. 2011; Alasaad et al. 2011).
Within this area exists a variety of mountain ranges, including the Sikhote-Alin mountains,
the Khingan (Xing’an) mountains, as well as the Changbai and Wandershan mountains, each
of which are characterised by high levels of forestation and therefore provide the preferred
habitat type for Siberian Tigers (Tian, Wu, Wang and Ge 2014).
In the late 1800’s it was estimated that throughout this range there were approximately
3000 Siberian tigers remaining (Tian et al. 2011). Today, however, there are approximately
only three major distribution areas in which Siberian tigers are found, the Sikhote-Alin
mountains, the Changbai and the Wandershan mountains (Tian et al. 2011). Furthermore,
in north eastern china, it is estimated that as little as 20 individuals remain (Liu et al. 2014)
and in far eastern Russia, only approximately 128,000km² is occupied and less than 400
individuals are assumed to remain (Goodrich et al. 2011).
It is estimated that as little as 7% of the historical range of the Siberian tiger is now
occupied (Dybas 2011).
3.4 INTRODUCED GEOGRAPHIC RANGE
There is no evidence of the Siberian tiger ever establishing feral, non-naturally occurring,
populations outside of their native geographical range. Furthermore, this species is not
currently, and has never been, recorded on the Global Invasive Species Database (Global
Invasive Species Database 2015).
3.5 POTENTIAL DISTRIBUTION IN TASMANIA
Using the CLIMATCH modelling application by the Bureau of Rural Science, a climate
comparison between the species’ distribution (both previous and current) and potential
Australian distribution is shown in Figure 1. This modelling indicates that Australia has no
areas in which the climate is similar to the natural range of Siberian tigers. Furthermore,
Tasmania’s climate is demonstrated as being highly dissimilar and therefore is not suitable
for this species to establish populations (highest climate match score = 0).
Figure 1. Climate comparison between the historical range of Siberian Tiger and Australia,
where 10 is a ‘perfect’ match and 0 is having a very dissimilar climate. Tasmania shows a
match of all zeros and therefore has a very dissimilar climate to the natural historical range
of Siberian tigers.
3.6 DIET AND FEEDING BEHAVIOUR
Siberian tigers (and all other tiger subspecies) are carnivores (Baker 2006) and their
preferred prey species is thought to be red deer and wild boar (Tian et al. 2014). However,
other prey types such as Sika and Roe deer, Siberian and Maral Wapiti (Elk), Asian black
bears, badgers and racoon dogs will also be readily hunted and consumed by Siberian tigers
(Hernandez-Blanco et al. 2015; Baker 2006). Much like other cat species, tigers have also
been known to consume grass as a source of roughage (Baker 2006). Tigers will devour all,
or almost all, of any prey species they kill, including bones, fat and visceral organs and
therefore nothing goes to waste (Baker 2006).
Due to the harsh climate experienced within their habitat, prey density for Siberian tigers is
often low (Kerley et al. 2003) and they are estimated to have a successful kill ratio of only 1
in every 20 attempts. Therefore, it is assumed that tigers will often choose to hunt the
largest of their prey species available (Baker 2006) as they are capable of taking down
animals more than double their size and larger hunts will provide them with food for many
more days (Baker 2006).
Tigers have been seen hunting at all times of the day and night, and their activity patterns
are mostly dictated by the sleep/activity patterns of their major prey species (Baker 2006).
Tigers silently stalk their prey, usually from within 9 and 21m, using their dark stripes as
camouflage through dense cover (Baker 2006). Tigers employ a variety of behaviours in
order to reduce their chance of being detected, including crouching down low to increase
camouflage, freezing for long periods of time should their prey become wary, and almost
always choosing to approach their prey from downwind (Baker 2006). Furthermore, tigers
may even chase their prey down into the water in order to increase their chances of making
a successful kill (Baker 2006).
Tigers will charge at their prey unexpectedly from behind (Tilson 2016). Small prey items are
usually easily killed by biting the animal on the neck, however larger prey items are latched
onto by the tiger and, using their jaw and forearms, they drag the prey to the ground. Once
the prey has been brought to the ground, the tiger then grabs the animals throat and holds
on until it suffocates (Tilson 2016).
Tigers will feed on large carcasses across several days until it is fully consumed, but are
capable of gorging themselves on as much as 20-30kg of meat in one sitting (Tilson 2016).
3.7 SOCIAL BEAHVIOUR AND GROUPINGS
Tigers are solitary, meaning they live and hunt alone (Tilson 2016), and each adult Siberian
tiger (usually 3 years and older) must have its own home range in order to successfully
survive and reproduce (Tian et al. 2011; Tilson 2016). The estimated home range for each
individual is thought to be between 120 and 565 km² (Hernandez-Blanco et al. 2015;
Miquelle and Rozhnov et al. 2015), with an average of between 360 and 445km² (Tian et al.
2011). Furthermore, Siberian tiger males will often have home ranges that overlap the
home ranges of either one, but usually two, or more female Siberian tigers, making them a
‘sex-specific territorial’ species (Hernandez-Blanco et al. 2015). Male home ranges,
however, will usually not allow any overlapping territory with other males and therefore
maintain exclusive breeding rights with any females inside his home range (Tilson 2016).
Interestingly, the size of an individual’s home range is thought to be mainly influenced by
the abundance of its food source and therefore home ranges are estimated to be much
larger in areas where food is scarce (such as Siberian tiger habitats), compared to when the
food source is in abundance (Baker 2006).
As tigers live in an interlinked social system it is not uncommon for them to encounter each
other during travel and may sometimes (though very rarely) even share a large kill (Baker
2006). Usually, however, their preference for a solitary lifestyle is maintained via means of
vocalisations as well as visual and scent markers and individuals will usually only meet up
each breeding season, for mating purposes (Baker 2006). Therefore, the only long-term
interaction that is ever demonstrated within Siberian tigers is between mothers and her
cubs, which can include day-to-day interaction for up to two years (Baker 2006).
The type of visual and scent marks often used by Siberian tigers includes, urine sprayed on
trees and bushes or left in prominent areas often travelled by neighbouring individuals, as
well as scattered faeces, scrapes on the ground or scratch marks in trees (Tilson 2016).
Scent and visual markers are redone regularly and can be used to also help males determine
when a female is in oestrus and therefore ready for mating (Tilson 2016).
3.8 NATURAL PREDATORS AND DISEASE
PREDATION
With the exception of humans, Siberian tigers do not have any natural predators. However,
conflict between humans and Siberian tigers is considered to be the worst of all the tiger
sub-species, with more humans being killed annually by Siberian tigers than any other subspecies (Goodrich et al. 2011).
Currently, throughout the entire remaining range of Siberian tigers there are humans and
conflict with the species can often result in the loss of human livelihood, when tigers kill
their domestic livestock, or loss of human life (Goodrich et al. 2011). These losses lead to
negative attitudes towards tigers, and any attempted tiger conservation, as well as
retaliatory killings and increased levels of poaching (Goodrich et al. 2011; Mukhacheva,
Derugina, Maksimova and Soutyrina 2015).
Although this conflict has been significantly reduced over the past century, mainly due to
the significant decline in Siberian tiger population numbers, human-tiger conflict almost
always leads to increased Siberian tiger mortality (Goodrich et al. 2011). This mortality can
be caused by humans either directly, via poaching or retaliatory killings, or indirectly via
means of prey loss, habitat degradation, fragmentation or loss as a result of logging or the
construction of roads, buildings and/or agriculture (Tian et al. 2011; Alasaad et al. 2011;
Robinson, Goodrich, Miquelle, Miller and Seryodkin 2015).
In order to decrease tiger mortality, and therefore increase population numbers, significant
effort must be taken to change the attitudes of humans in which share their habitat.
DISEASE
In aged, captive tigers, respiratory kidney and liver diseases often cause significant
problems. Furthermore, Siberian tigers are capable of carrying and catching a variety of
diseases including, bacterial, viral and parasitic (Williams and Throne 1996).
Bacterial:
 Bovine Tuberculosis (TB) has been known to occur in Siberian tigers and is most often


contracted via contaminated meat and/or offal (Williams and Throne 1996). This disease
effects the animal’s lungs and is long-lasting and often difficult to treat (Tilson 2016).
Bacillus anthracis causes Anthrax and has been found to lead to fatalities in large captive
felids, such as tigers. This disease is capable of causing death to the animal in a little as
1-4 days and is known to cause blood clots in the animal’s spleen (Tilson 2016). Much
like, Tuberculosis, Anthrax is most often contracted via exposure to a contaminated
food source (Williams and Throne 1996).
Other bacterial diseases have been reported such as: bacterial meningitis, Clostridium,
Colisepticemia, Corynebacterium pyogenes, Perfingens, Salmonella spp. and Shigella
flexaeri, all of which effect the body’s ability to either transport oxygen to or carbon
dioxide from the lungs (systemic diseases) (Tilson 2016).
- Salmonella spp. have been known to cause issues for both tiger cubs and adults and,
if contracted, can cause symptoms ranging from mild gastrointestinal upset to
fatalities (Tilson 2016). Thankfully, good quality control of their food source in
captivity is an effective way of reducing the chances of infection from such bacteria
(Tilson 2016).
Parasitic:
Large, wild felids are capable of contracting parasites such as Trichinella spiralis and
Toxoplasma gondii, however most cestode parasites are not harmful to the large felid
species that carry them but may be harmful to other species that are capable of catching it
(Williams and Throne 1996). For instance, felids have been found to carry the parasite
Echiococcus multicularis which does not cause them any significant illness, but if contracted
and left untreated in humans has been known to result in fatalities (Williams and Throne
1996). Furthermore, the parasite Microsporus canis has been known to effect tiger cubs and
cause hairloss, luckily it is easily treated (Tilson 2016).
Viral:
Large felids, such as tigers, are capable of contracting a variety of viral illnesses such as
pseudorabies and respiratory illnesses including feline rhinotracheitis, panleukopenia, feline
infectious deritonitis and feline calicivirus (Williams and Throne 1996; Tilson 2016). Such
viruses however, are considered mild and result only in rash (pseudorabies), have
vaccinations that are proven effective for both domestic and wild feline species
(rhinotracheitis and clicivirus) or have low mortality rates if contracted (Williams and
Throne 1996; Tilson 2016).
One other viral disease, however, has been recently considered as a serious pathogen and is
capable of being contracted by a variety of wild feline species, such as lions, leopards and
tigers (Nagao 2012). This virus is known as the Canine Distemper Virus (CDV) and has been
found to result in a number of Siberian and Bengal tiger deaths in captivity (and the wild)
since 1983 (Williams and Throne 1996). CDV is within the Morbillivirus genus, has a single
stranded RNA genome and is caused by a Paramyxovirus (Nagao 2012; Gilbert et al. 2014).
This virus primarily infects the alveolar macrophages within the lungs, before spreading
throughout the lymphatic system and is transmitted mainly during close contact with
contaminated individuals through the respiratory tract (Gilbert et al. 2015). However,
transmission via contaminated urine or faeces has also been demonstrated (Gilbert et al.
2015).
CDV has been shown to cause a variety of symptoms including: fever and laboured
breathing, nasal discharge, diarrhea, anorexia and dehydration, all of which occur in the
early stages of contraction (Tilson 2016; Gilbert et al. 2015; Nagao 2012). However, once
progressed more serious symptoms such as behavioural changes (with some becoming
unafraid of humans), muscle twitches and even seizures have been demonstrated (Tilson
2016; Gilbert et al. 2015; Nagao 2012). Unfortunately, once contracted the outcome is often
fatal (Nagao 2012), with many animals dying during the initial stages of the spread or
relapsing in the future should they be lucky enough to survive the first time (Tilson 2016;
Gilbert et al. 2015). Evidence from captive individuals has shown that the virus can lie
dormant in the body, after the initial contamination, for as many as 150 days (Gilbert et al.
2015).
Many of the diseases listed above including, TB, Rabies, Anthrax and Salmonella spp. are
known zoonoses and therefore are capable of being passed from human to tiger, and visa
versa. All precautions should be taken to ensure that such diseases, should they be
contracted, are not passed between individuals or species (Tilson 2016; Nagao 2012).
3.9 THREAT TO HUMAN SAFETY
Historically, tigers have been known to kill and injure large numbers of people and as a
result are often regarded as one of the most likely species, all of the large felids, to be
involved in conflicts with humans (Goodrich et al. 2011). Unfortunately, at present humantiger conflict still exists and is thought to occur everywhere the two species co-exist, with
attacks on humans occurring annually (Goodrich et al. 2011). However, due to the
encroachment of human populations into tiger territories many of these killings are likely to
be due to tigers attempting to protecting their cubs (or themselves) from poaching or
retaliatory killings from humans when tiger prey gets low and they are forced to hunt
domestic livestock.
It is a widely believed view that once tigers have a taste for human flesh, they are likely to
begin actively hunting them as a source of prey (Baker 2006). However, tigers do not
normally view humans as prey and only in extreme circumstances will tigers actively hunt
humans for food (Baker 2006). Such circumstances include, when the tiger is old, sick or
injured and therefore is no longer able to catch its natural prey source (Baker 2006).
Therefore, assuming the highly unlikely event that a Siberian tiger should be loose in
Tasmania human safety could be compromised. However, a captive tiger that has never
encountered human flesh before is only likely to attack should it become startled or feel
threatened.
3.10 HISTORY AS A PEST
Siberian tigers are not currently considered as a pest species. Furthermore, they have not
been known to establish feral (non-native) populations outside of their native range and are
not recorded on the Global Invasive Species Database (Global Invasive Species Database
2015). To date, no introduction attempts have been noted.
However, Siberian tigers are capable of impacting agriculture as it is known that when their
natural prey source becomes scarce (usually through overhunting of their prey by humans)
Siberian tigers will turn to hunting domestic livestock as a source of prey (Robinson et al.
2015).
3.11 POTENTIAL IMPACT IN TASMANIA
Siberian tigers would likely consume native wildlife, such as Bennetts wallabies (Macropus
rufogriseus), Paedemelons (Thylogale billardierii) and potentially even Tasmanian devils
(Sarcophilus harrisii), but would happily eat any prey item that it came across, potentially
decimating native populations. However, since Tasmania’s native species are small
compared to the sorts of prey consumed by Siberian tigers in the wild, it is likely that
domestic livestock such as sheep and cattle would become the major source of prey for
Siberian tigers in Tasmania. Ramifications from this would of course result in the loss of
livelihood for farmers and the potential for the loss of human life should any human-tiger
conflict arise as a result of tigers hunting livestock.
However, in the extremely unlikely event that a Siberian tiger should find itself free in the
Tasmanian ecosystem, their infrequency to ovulate, paired with the very short time they are
fertile, plus their wild mortality rate and the length of time for cubs to become independent
and reach sexual maturity would all contribute to making it extremely unlikely to establish a
feral population, Furthermore, their size, the public uproar and the damage they would
cause from feeding on livestock, as we have no other large carnivores in the state, would
therefore make them easily trackable. Additionally, climate modelling shows that
Tasmania’s climate is unsuitable for the continued survival of Siberian tigers. Therefore,
establishment of this species is severely unlikely.
4.
RISK ASSESSMENT
4.1 PREVIOUS RISK ASSESSMENT
The Siberian Tiger has previously been assessed by the Commonwealth Vertebrate Pest
Committee (VPC 2007) as an ‘extreme’ risk. Therefore, under this VPC classification Siberian
tigers may only be kept by those who hold a permit for education, conservation,
entertainment and/or exhibition (VPC 2007).
In Tasmania, the Siberian tiger would likely be considered a ‘controlled animal’ under the
Nature Conservation Act 2002, however, the Siberian tiger has not yet been considered for
importation into Tasmania.
5.
REFERENCES
Alasaad, S., Soriguer, R.C., Chelomina, G., Petrovich Sushitsky, Y. & Fickel, J. (2011). Siberian
tiger’s recent population bottleneck in the Russian Far East revealed by microsatellite
markers. Mammalian Biology 76 (6). P. 722-726.
Baker, R. (2006). The tiger Panthera tigris. A husbandry manual submitted to the Western
Sydney Institute of TAFE in partial fulfilment of the conditions of application for the
Certificate III in Captive Animals. Western Sydney of TAFE, Richmond.
Dybas, C.L. (2010). The once and future tiger. BioScience 60 (11). P. 872-877.
Fukui, D., Nagano, M., Nakamura, R., Bando, G., Nakata, S., Kosuge, M., Sakamoto, H.,
Matsui, M., Yanagawa, Y. & Takahashi, Y. (2013). The effects of frequent electroejaculation
on the semen characteristics of a captive Siberian tiger (Panthera tigris altaica). Journal of
Reproduction and Development 59 (5). P. 491-495.
Gilbert, M., Miquelle, D.G., Goodrich, J.M., Reeve, R., Cleaveland, S., Matthews, L. & Joly,
D.O. (2014). Estimating the potential impact of canine distemper virus (CDV) on the Amur
tiger population (Panthera tigris altaica) in Russia. PLoS ONE 9 (10). P. 1-9.
Gilbert, M., Soutyrina, S.V., Seryondkin, I.V., Sulikhan, N., Uphyrkina, O.V., Goncharuk, M.,
Matthews, L., Cleaveland, S. & Miquelle, D.G. (2015). Canine distemper virus as a threat to
wild tigers in Russia and across their range. Integrative Zoology 10 (4). P. 329-343.
Global Invasive Species Database (GISD) (2015) (http://www.issg.org/database).
Goodrich, J.M., Seryodkin, I., Miquelle, D.G. & Bereznuk, S.L. (2011). Conflicts between
Amur (Siberian) tigers and humans in the Russian Far East. Biological Conservation 144 (1).
P. 584-592.
Hernandez-Blanco, J.A., Naidenko, S.V., Chistopolova, M.D., Lukarevskiy, V.S., Kostyrya, A.,
Rybin, A., Sorokin, P.A., Litvinov, M.N., Kotlyar, A.K., Miquelle, D.G. & Rozhnov, V.V. (2015).
Social structure and space use of Amur tigers (Panthera tigris altaica) in Southern Russian
Far East based GPS telemetry data. Integrative Zoology 10 (4). P. 365-375.
Kerley, L.L., Goodrich, J.M., Miquelle, D.G, Smirnov, E.N., Quigley, H.B. & Hornocker, M.G.
(2003). Reproductive parameters of wild female Amur (Siberian) tigers (Panthera tigris
altaica). Journal of Mammology 84 (1). P. 288-298.
Liu, C., Bai, C., Guo, Y., Liu, D., Lu, T., Li, X., Ma, J., Ma, Y. & Guan, W. (2014). Construction
and analysis of the Siberian tiger bacterial artificial chromosome library with approximately
6.5 fold genome equivalent coverage. International Journal of Molecular Science 15 (3). P.
4189-4200.
Nagao, Y., Nishio, Y., Shiomoda, H., Tamaru, S., Shimojima, M., Goto, M., Une, Y., Sato, A.,
Ikebe, Y. & Maeda, K. (2012). An outbreak of canine distemper virus in tigers (Panthera
tigris): Possible Transmission from wild animals to Zoo animals. Journal of Veterinary
Medical Science 76 (6). P. 699-705.
Miquelle, D., Darman, Y. & Seryodkin, I. (2011). Panthera tigris ssp. altaica. The IUCN Red
List of Threatened Species 2011: e.T15956A5333650.
http://dx.doi.org/10.2305/IUCN.UK.2011-2.RLTS.T15956A5333650.en. Downloaded on 06
February 2016.
Miquelle, D.G., Rozhnov, V.V., Ermoshin, V., Murzin, A.A., Nikilaev, I.G., Hernandez-Blanco,
J.A. & Naidenko, S.V. (2015). Identifying ecological corridors for Amur tigers (Panthera tigris
altaica) and Amur leopards (Panthera pardus orientalis). Integrative Zoology 10 (4). P. 389402.
Miquelle, D.G., Smirnov, E.N., Zaumyslova, O.Y., Soutyrina, S.V. & Johnson, D.H. (2015).
Population dynamics of Amur tigers (Panthera tigris altaica) in Sikhote-Alin biosphere
ZapovednikL 1966-2012. Integrative Zoology 10 (4). P. 315-328.
Mukhacheva, A.S., Derugina, V.V., Maksimova, G.D. & Soutyrina, S.V. (2015). Amur tiger
conservation education program: A pilot study on program effectiveness. Integrative
Zoology 10 (4). P. 403-407.
Robinson, H.S., Goodrich, J.M., Miquelle, D.G., Miller, C.S. & Seryodkin, I.V. (2015). Mortality
of Amur tigers: The more things change, the more they stay the same. Integrative Zoology
10 (4). P. 344-353.
Shoemaker, A.H., Maruska, E.J. & Rockwell, R. (1997). Minimal husbandry guidelines for
mammals: Large felids. American Association of Zoos and Aquariums.
Song, J., Hua, S., Song, K. & Zhang, Y. (2007). Culture, characteristics and chromosome
complement of Siberian tiger fibroblasts for nuclear transfer. In Vitro Cellular and
Developmental Biology 43 (7). P. 203-209.
Tian, Y., Wu, J., Smith, A.T., Wang, T., Kou, X. & Ge, J. (2011). Population viability of the
Siberian tiger in a changing landscape: Going, going and gone? Ecological Modelling 222
(17). P. 3166-3180.
Tian, Y., Wu, J., Wang, T. & Ge, J. (2014). Climate change and landscape fragmentation
jeopardise the population viability of the Siberian tiger (Panthera tigris altaica). Landscape
Ecology 29 (4). P. 621-637.
Tilson, R. (2016). Natural History and Status of Tigers. Sourced from Tiger Missing Link
Foundation: https://www.tigerlink.org/husbandry/husman1.htm.
Vertebrate Pests Committee (VPC). List of Exotic Vertebrate Animals in Australia, July 2007,
Environment Australia.
Williams, E.S. & Throne, E.T. (1996). Infectious and parasitic diseases of captive carnivores,
with special emphasis on the black-footed ferret (Mustela nigripes). Scientific and Technical
Review of the Office International des Epizooties (Paris) 15 (1). P. 91-114.