Geographic Range
Prionailurus iriomotensis
is endemic only to Iriomote Island, the southernmost isle in the Ryukyu Archipelago,
Japan. The island is approximately 284 km^2.
- Biogeographic Regions
- palearctic
- Other Geographic Terms
- island endemic
Habitat
The island of Iriomote consists mainly of lowland mountains. The highest point on
the island is 469 m on Mt. Komidake. Cover is composed of broad-leaved, evergreen,
and sub-tropical primary forest over a majority of the mountainous regions. Mangrove
forests are common among the estuaries. Cleared areas along with cultivated fields
are found in the area of coastal flats. Iriomote cats range throughout the mountains
and forested areas, and sometimes appears along the coastal beaches and villages.
- Habitat Regions
- tropical
- terrestrial
- Terrestrial Biomes
- forest
- rainforest
- mountains
- Other Habitat Features
- agricultural
- estuarine
Physical Description
The fur of
P. iriomotensis
is dark brown and of medium length. Dark spots occur in rows along the body, and
dark stripes are prevalent along the neck. The posterior surface of the ears of Iriomote
cats are marked by white spots. Ther is a characteristic white area surrounding the
eyes. The irises vary from yellowish-gold to amber.
The body shape of this species is somewhat elongated. The legs are relatively short,
as is the tail, giving these animals a "low-slung" appearance. The average length
is between 70 and 90 cm. Weight for males averages 4.2 ± 0.5 kg (n=15) and for females
3.2 ± 0.3 kg (n=10).
- Other Physical Features
- endothermic
- homoiothermic
- bilateral symmetry
- Sexual Dimorphism
- sexes alike
Reproduction
Very little is known about the mating habits of
P. iriomotensis
. In one study, only six of 686 reported chance observations of Iriomote cats resulted
in pair sightings. However rare, these sightings all occurred between December and
March, indicative of the presumed breeding season, and suggesting a monogamous breeding
system. A male and female exhibiting "courtship behavior" were observed in the month
of January. Marking frequency in males showed a peak through the months of February
to April. Marking through urine is presumed to increase in response to the breeding
season. The male of captive pair was also observed to increase marking frequency
during breeding activity.
- Mating System
- monogamous
The breeding season seems to occur primarily from winter to spring but may not be
seasonally restricted. Most mating likely proceeds from February to March, based on
the distribution of birth months from April to July. There was a clear peak in births
for the month of May. Gestation is estimated at 60 days based on observations of
leopard cats (
Prionailurus bengalensis
).
Litters most commonly have a single kitten. However, twins have been reported. In
one study the majority of kittens observed were single and out of 41 chance observations
of mothers and offspring, only four produced twins. One source states that there
have been no documented reports of Iriomote cats having a litter size exceeding two.
The mother nurses her offspring until they are abouttwo to three months old. Even
after weaning, maternal care continues until the kittens are 4 to 4.5 months of age.
Animals reach sexual maturity around the age of 8 months.
- Key Reproductive Features
- iteroparous
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- fertilization
- viviparous
In
P. iriomoensis
, as in most mammals, all aspects of parental care, including food procurement, protection,
adequate resources, and teaching, are provided solely by the female. As the altricial
kittens develop in a den of some type, the mother provides them with milk, protection,
and grooming. After the kittens are able to follow the mother, they must be taught
to hunt for themselves. The mother appers to do this alone, as well.
Territory has been observed to be shared between mothers and daughters up to 6.5 months
of age, inidcating a post-independence association between mothers and their female
offspring. Weaning occurs from 2 to 3 months of age, and independence is established
from 4 to 4.5 months of age.
- Parental Investment
- no parental involvement
- altricial
-
pre-fertilization
-
protecting
- female
-
protecting
-
pre-hatching/birth
-
provisioning
- female
-
protecting
- female
-
provisioning
-
pre-weaning/fledging
-
provisioning
- female
-
protecting
- female
-
provisioning
-
pre-independence
-
provisioning
- female
-
protecting
- female
-
provisioning
- post-independence association with parents
- extended period of juvenile learning
- inherits maternal/paternal territory
Lifespan/Longevity
Information about life span is predicated upon comparisons to leopard cats ( P. bengalensis ) due to the lack of longevity studies on P. iriomotensis in the wild or in captivity.
Leopard cats can live up to 15 years, but tooth loss generally occurs between the
ages of 8 to 10 years. It is likely that Iriomote cats are similar.
Behavior
Prionailurus iriomotensis
is usually solitary, but may form pairs when breeding. Territories range from 1
to 3 square kilometers. Males have larger territories than females. Male territories
can overlap whereas female territories are less likely to do so. Females also exhibit
more stable home ranges and seem to use a consistent feeding site for several years,
whereas males shift their areas of activity after several months.
Iriomote cats are active mainly from evening to early morning, but occasionally do
hunt during the day, when they apparently prey upon a skink species (
Eumeces kishinouyei
) that is only diurnal and estivates from dusk till dawn.
Although they often tracel along the ground, Iriomote cats exhibit arboreal agility.
This suggests that they spend some of their time hunting or resting in trees.
- Key Behaviors
- arboreal
- terricolous
- diurnal
- nocturnal
- crepuscular
- motile
- sedentary
- solitary
- territorial
Home Range
Home range sizes for this species range from 1 to 3 square km.
Communication and Perception
Iriomote cats rarely vocalize, but during the breeding season they can be heard.
Mating sounds are similar to domestic cats. Thi species is also reported to make
low murmuring "bow-wow" sounds when fighting. Scent marking is integral in intra-specific
communication relaying information on territory and sexual receptiveness. Tactile
communication is undoubtedly important between a mother and her kittens, between mates,
and between competitors in aggonistic circumstances.
- Other Communication Modes
- pheromones
- scent marks
Food Habits
Prionailurus iriomotensis
is opportunistic, and will feed on almost all the animals that can be found on the
island. Their diet includes small mammals (such as fruit bats and rats); birds, snakes,
frogs, lizards, insects and occasionally fish and crabs. After a kill, Iriomote cats
have been observed to temporarily abandon the kill, but are speculated to occupy the
general vicinity during the vacated time.
- Primary Diet
-
carnivore
- eats terrestrial vertebrates
- Animal Foods
- birds
- mammals
- amphibians
- reptiles
- fish
- insects
- aquatic crustaceans
Predation
There are no documented predators or Iriomote cats.
Ecosystem Roles
Iriomote cats are key predators in the island ecosystem preying on a variety of organisms.
Though the cats are efficient predators, the impact on the community is minimal due
to their small population size.
Economic Importance for Humans: Positive
Iriomote cats are charismatic, and are becoming a major source of tourist appeal.
This brings in economic revenue.
- Positive Impacts
- ecotourism
Economic Importance for Humans: Negative
Some locals view this species as an obstruction to economic development. There have
been proposals to conserve lowland habitat for these cats, but since such areas are
potentially important agricultural areas, there is a direct conflict between the cats
and the humans on the island.
Conservation Status
Prionailurus iriomotensis is considered highly endangered. It is the world's most vulnerable and rarest felid species, based on the minute range and small population size. The population is estimated to be less than 100 individuals.
Prionailurus iriomotensis
is placed under CITES Appendix II, and has been fully protected since 1967. Habitat
destruction is the prominent threat.
Other Comments
Establishing a concrete taxonomic status for Iriomote cats is proving to be difficult.
A sample study analyzing genetic material suggested that Iriomote cats are in fact
a distinct species from
P. bengalensis
. The population of
P. iriomotensis
has experienced at least one if not many "extreme demographic bottlenecks". Current
evidence suggests that the entire population of this species is derived from as few
as two females and one male.
Additional Links
Contributors
Nancy Shefferly (editor), Animal Diversity Web.
Holly Schroeder (author), University of Wisconsin-Stevens Point, Chris Yahnke (editor), University of Wisconsin-Stevens Point.
- Palearctic
-
living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- island endemic
-
animals that live only on an island or set of islands.
- tropical
-
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
- terrestrial
-
Living on the ground.
- forest
-
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
- rainforest
-
rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.
- mountains
-
This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.
- agricultural
-
living in landscapes dominated by human agriculture.
- estuarine
-
an area where a freshwater river meets the ocean and tidal influences result in fluctuations in salinity.
- endothermic
-
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
- bilateral symmetry
-
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
- monogamous
-
Having one mate at a time.
- iteroparous
-
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
- seasonal breeding
-
breeding is confined to a particular season
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- fertilization
-
union of egg and spermatozoan
- viviparous
-
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
- altricial
-
young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.
- arboreal
-
Referring to an animal that lives in trees; tree-climbing.
- diurnal
-
- active during the day, 2. lasting for one day.
- nocturnal
-
active during the night
- crepuscular
-
active at dawn and dusk
- motile
-
having the capacity to move from one place to another.
- sedentary
-
remains in the same area
- solitary
-
lives alone
- territorial
-
defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
- pheromones
-
chemicals released into air or water that are detected by and responded to by other animals of the same species
- scent marks
-
communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
- ecotourism
-
humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.
- carnivore
-
an animal that mainly eats meat
References
Hemmer, H. 1978. The Evolutionary Systematics of Living Felidae: Present Status and Current Problems. Carnivore , 1(1): 71-79.
Johnson, W., F. Shinyashiki, M. Menotti Raymond, C. Driscoll, C. Leh, S. Wasser . 1999. Molecular Genetic Characterization of Two Insular Asian Cat Species, Bornean Bay Cat and Iriomote Cat. Pp. 223-248 in Evolutionary Theory and Processes: Modern Perspectives . Klewar Academic Publishers.
Okamura, M., T. Doi, N. Sakaguchi, M. Izawa. 2000. Annual Reproductive Cycle of the Iriomote cat *Felis iriomotensis*. Mammal Study , 25(2): 75-85.
Yasuma, S. 1988. Iriomote Cat: King of the Night. Animal Kingdom , 91(6): 12-21.
International Society for Endangered Cats Canada (ISEC Canada). 2001. "Iriomote cat" (On-line ). Accessed 10/09/02 at http://www.wildcatconservation.org/cats/factsheets/asia/iriomote/index.shtml .
IUCN Cat Specialist Group - The World Conservation Union. 1996. "Iriomote cat" (On-line). Accessed October 09, 2002 at http://lynx.uio.no/catfolk/sp-accts.htm .