Dendrolagus scottaetenkile tree kangaroo

Geographic Range

Tenkile tree kangaroos are found only Papua New Guinea, and only in Sandaun Province along the Torricelli Mountains in the rainforests on the southern side of Mount Sumoro. Today, the total area occupied by these tree kangaroos is only about 50 square kilometers. (Massicot, 2002; "Melbourne Zoo", 1998; "Tenkile Info", 2003)

Habitat

The rainforest canopy on the southern side of Mount Somoro is now the only home to tenkile tree kangaroos. This habitat is at elevations of 900 to 1500 meters. (Massicot, 2002)

  • Range elevation
    900 to 1500 m
    2952.76 to 4921.26 ft

Physical Description

The body mass of Dendrolagus scottae averages 10 kg. Tree kangaroos have bodies that are built for climbing up and down trees and for moving along tree branches. The tail is similar to that of other macropods, but the tenkiles are more adapted for maneuvering through the upper levels of the rainforest. Good balance and agility are needed to be able to jump or move from tree to tree without falling to the forest floor. These qualities are enhanced by the tenkiles' floppy tails. Large foreclaws enable these animals to grasp tree branches and climb through the canopy with ease. Their fur is a dark brown color and, like many other marsupials, they have a pouch used in the development of offspring. (Massicot, 2002; "Tenkile Info", 2003)

  • Average mass
    10 kg
    22.03 lb

Reproduction

There is very little information on Dendrolagus scottae or other Dendrolagus species. In captivity, males of other Dendrolagus species will fight in the presence of females. (Nowak, 1991)

Research on Scott's tree kangaroos suggests that these animals breed throughout most of the year. Females will give birth to young at 12 month intervals. Like most macropods, Scott's tree kangaroos give birth to one offspring at a time. (Flannery, 1995; Massicot, 2002; Nowak, 1991)

In other tree kangaroo species, gestation lasts about 32 days, young emerge from the pouch at about 305 days, and cease to crawl into the pouch to suckle at 408 days. (Nowak, 1991)

  • Breeding interval
    Tree kangaroos give birth once yearly, on average.
  • Breeding season
    Breeding occurs throughout most of the year.
  • Average number of offspring
    1

Like other kangaroos, female Scott's tree kangaroos carry their young in a pouch until the joey is large enough and old enough to emerge. This time period is usually ten to twelve months. The young are nursed from birth until the young are more than a year old. (Nowak, 1991)

Lifespan/Longevity

There is little information on longevity in D. scottae, however other tree kangaroos are known to live 20 years or more in captivity. (Nowak, 1991)

  • Range lifespan
    Status: captivity
    20 (high) years

Behavior

Tenkiles or Scott's tree kangaroos are diurnal and mainly terrestrial, though they can climb to escape predators and danger. Native people report that they were previously encountered mainly in groups of 4 animals, including a male, female, and their young, but are more commonly found as solitary females and young in recent years, this may be the result of severe population declines in recent years. In the wild, females may have a few acres as their territory, while males maintain a much larger territory. (Massicot, 2002)

Other tree kangaroo species are mainly arboreal. They are capable of large leaps from the ground into the trees and from tree to tree. On the ground they move with small hops. On the ground the tail is held arched over their back and the head leans far forward. Related females may form social groups that cooperate in defense against unfamiliar males. (Nowak, 1991)

Communication and Perception

Little is known about how tenkiles communicate, however it is likely that they use the full suite of available senses to communicate and perceive their environment, including vision, chemical cues, touch, and hearing. (Massicot, 2002)

Food Habits

Tenkiles, or Scott's tree kangaroos, are mainly herbivorous. Their primary diet consists of tree leaves, ferns, and soft vines. They may forage in the trees or on the ground. (Massicot, 2002)

  • Plant Foods
  • leaves
  • roots and tubers

Predation

The main predator of Scott's tree kangaroos is humans. Tribal hunters in the areas of the Torricelli Mountains are hunting these animals resulting in rapidly decreasing populations. They are used for meat and skins. The young are also being killed for their skins, or they are being captured and kept as pets. Little is known about any anti-predator adaptations in this species. ("Tenkile Info", 2003)

Ecosystem Roles

Tenkile tree kangaroos impact plant communities in the ecosystems in which they live through their predation on plants. Little is known of other impacts they may have. (Massicot, 2002; Nowak, 1991)

Economic Importance for Humans: Positive

Humans use tenkile tree kangaroos as a source of food and fur and sometimes keep them as pets. (Massicot, 2002)

  • Positive Impacts
  • pet trade
  • food
  • body parts are source of valuable material

Economic Importance for Humans: Negative

There are no known adverse affects of tenkile tree kangaroos on humans.

Conservation Status

Scott's tree kangaroos, which were first discovered in 1989, are thought to be the rarest tree kangaroo species. Wild populations are rapidly declining, and is now thought to be less than 200 individuals. This is about a 75% reduction since the species was first discovered. The main reason for these falling numbers is hunting by the increasing human population and habitat loss. To deal with this unfortunate population decline, the Tenkile Conservation Alliance was formed in 1999. This conservation group is working to maintain the failing habitat of this rare species. If action is not taken soon, the tenkile population is likely to be extinct within just a few years. (Massicot, 2002; "Melbourne Zoo", 1998; "Tenkile Info", 2003)

Other Comments

Dendrolagus scottae individuals have a strong odor, which can last for up to a week on items that an animal comes in contact with (e.g. a handler's hands). Another interesting tidbit about these animals is how they received the common name 'Scott's Tree Kangaroo'. The story is that there was a trust fund named after a man called Winifred Scott. After his death in 1985, the Permanent Trustee Company, a co-trustee of the Scott Trust, donated the trust income to an Australian Museum research program. Participants in this program discovered the tenkile. In honor of Winifred, this species of tree kangaroo was given the name Scott's tree kangaroo. (Massicot, 2002; "Wills, Trusts, and Estate Planning", 2003)

Contributors

Lindsay Cosens (author), Michigan State University, Barbara Lundrigan (editor), Michigan State University.

Glossary

Australian

Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

World Map

acoustic

uses sound to communicate

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.

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.

chemical

uses smells or other chemicals to communicate

diurnal
  1. active during the day, 2. lasting for one day.
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.

female parental care

parental care is carried out by females

folivore

an animal that mainly eats leaves.

food

A substance that provides both nutrients and energy to a living thing.

herbivore

An animal that eats mainly plants or parts of plants.

island endemic

animals that live only on an island or set of islands.

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).

motile

having the capacity to move from one place to another.

pet trade

the business of buying and selling animals for people to keep in their homes as pets.

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.

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

terrestrial

Living on the ground.

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

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

year-round breeding

breeding takes place throughout the year

References

Zoological Parks and Gardens Board. 1998. "Melbourne Zoo" (On-line ). Scott's Tree Kangaroo. Accessed 04/11/03 at http://www.zoo.org.au/animals/treekangaroo.htm.

Tenkile Conservation Alliance, Inc. 2003. "Tenkile Info" (On-line ). Accessed 04/11/03 at http://www.unitech.ac.pg/TCA/tenkileinfo.html.

Permanent Trustee Company, Ltd. 2003. "Wills, Trusts, and Estate Planning" (On-line ). Media Releases. Accessed 04/11/03 at . http://www.permanent-trustee.com.au/wills/charitable_fs.htm.

Flannery, T. 1995. Mammals of New Guinea. Ithaca, New York: Cornell University Press.

Massicot, P. 2002. "Animal Info" (On-line ). Tenkile. Accessed 04/11/03 at http://www.animalinfo.org/species/dendscot.htm.

Nowak, R. 1991. Walker's Mammals of the World. Baltimore: The Johns Hopkins University Press.