Macropus fuliginosuswestern gray kangaroo

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Geographic Range

This species of kangaroo is found in the southern part of the continent of Australia including southern Queensland, southern New South Wales, and western Victoria. In addition, it is found on Kangaroo Island off of the southern coast of Australia.

Habitat

Western grey kangaroos are capable of using several different types of habitats. They can be found in woodlands, open forests, coastal heathland, and open grassland areas. They have also been found near city areas and on golf courses. These kangaroos prefer areas with heterogeneous habitats, because these areas are the most likely to meet their requirements for food and cover.

Physical Description

This species exhibits sexual dimorphism, whereby males are larger than females. Western grey kangaroos vary in color from light brown to reddish shades of dark brown. They have a pale throat, chest and abdomen. The muzzle is distinctly different from other kangaroo species in that it is covered with much finer hair. These kangaroos can grow to be as large as 7 ft. tall. The tail is used as a balance in locomotion. Tail length ranges from 425-1000mm in males and 438-815mm in females. Muscle mass makes up approximately 80% of the body weight for this species.

  • Range mass
    3 to 53.5 kg
    6.61 to 117.84 lb
  • Range length
    946 to 2225 mm
    37.24 to 87.60 in

Reproduction

Males compete for females, whereby dominant males mate. Dominancy is determined through "boxing", which is a form of male competition.

Western grey kangaroos can breed continuously, but a peak in reproductive activity exists in the seasons of spring and summer. Sexual maturity is reached at approximately 20 months for males and 17 months for females. Females have an oestrous cycle of approximately 35 days. Interestingly, the western grey kangaroo is not capable of embryonic diapause. Usually, only a single offsping weighing approximately 0.8g is born after a mean gestation period of 30.5 days. The offsping, commonly called a joey, will climb from the birth canal to the pouch where it grabs hold of a teat and nurses. The joey will begin to leave the pouch after an average of 46 weeks, and may continue to nurse from the pouch for up to an additional 6 months after leaving the pouch. After the joey has left the pouch, the female is capable of mating again.

  • Breeding season
    year round with a peak in spring and summer
  • Range number of offspring
    1 to 1
  • Average number of offspring
    1
    AnAge
  • Average gestation period
    30.5 days
  • Average gestation period
    30 days
    AnAge
  • Average weaning age
    18 months
  • Average age at sexual or reproductive maturity (female)
    17 months
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    670 days
    AnAge
  • Average age at sexual or reproductive maturity (male)
    20 months
  • Average age at sexual or reproductive maturity (male)
    Sex: male
    880 days
    AnAge

Generally, exclusively the female cares for the young.

Lifespan/Longevity

Western grey kangaroos have lived to be upward of 20 years old in captivity. However, the maximum lifespan of these kangaroos in the wild is approximately 10 years.

Behavior

Western grey kangaroos form social groups called "mobs" consisting of kangaroos living in small family groups with an adult female as the matriarch, other group member females, and young. A daughter often remains close to her mother even after giving birth to a joey of her own. Males compete for dominance of the social groups, with the strongest male becoming the head of a mob. A dominant male kangaroo resides with the mob when females are fertile but separates from the mob in winter when breeding females are unlikely to come into oestrus. During breeding, young males may form single-sex groups that exist seperately from the mobs. Mature males may form loose associations with other males which are not long lasting and vary from year to year. Western grey kangaroos may have home ranges that are as large as 550ha.

Communication and Perception

Food Habits

Western grey kangaroos eat grasses, forbs, leaves, tree bark, and shrubby browse. They use microorganisms in an organ called the cecum to digest the cellulose of plants. This kangaroo requires very little water and is able to survive on plants high in fiber. Western grey kangaroos spend between 6 and 10 hours grazing per day, mostly at dawn and dusk. In captivity, these kangaroos are often fed a pelleted grain or hay.

  • Plant Foods
  • leaves
  • wood, bark, or stems

Predation

The dingo (Canis familiaris dingo) preys upon the western grey kangaroo. Healthy large males are usually not preyed upon by the dingo because of their size. However, young and old age classes are vulnerable to predation by the dingo.

Ecosystem Roles

The western grey kangaroo controls vegetation growth by feeding on grasses and forbs.

Economic Importance for Humans: Positive

Tourists enjoy viewing this species of kangaroo on golf courses and in national parks. Australian kangaroo meat is marketed throughout the world as a quality game meat.

Economic Importance for Humans: Negative

Crops and pasteurs may be damaged by western grey kangaroos through their foraging in these areas.

  • Negative Impacts
  • crop pest

Conservation Status

Despite the crop damage from this kangaroo species, it is a protected species and is controlled exclusively by the state faunal authorities. In 1987, there was an estimated population of 1.7 million western grey kangaroos. Permits to harvest the western grey kangaroo are issued in areas where this species interferes with successful agricultural operations or management programs to rehabilitate vegetation communities.

Other Comments

There are two subspecies of western grey kangaroo, Macropus fuliginosus fuliginosus on Kangaroo Island, and Macropus fuliginosus melanops on mainland Australia.

The western grey kangaroo has a tolerance to fluoroacetate, which is a poison present in many legumes in southwestern Australia.

Contributors

David Miller (author), University of Michigan-Ann Arbor, Kate Teeter (editor), University of Michigan-Ann Arbor.

Glossary

Australian

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

World Map

agricultural

living in landscapes dominated by human agriculture.

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.

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

dominance hierarchies

ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates

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.

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.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

herbivore

An animal that eats mainly plants or parts of plants.

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.

native range

the area in which the animal is naturally found, the region in which it is endemic.

polygynous

having more than one female as a mate at one time

scrub forest

scrub forests develop in areas that experience dry seasons.

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

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

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

urban

living in cities and large towns, landscapes dominated by human structures and activity.

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

Anonymous, January 1, 2001. "Plants & Animals: Western Grey Kangaroo" (On-line). Accessed October 8, 2001 at http://www.calm.wa.gov.au/plants_animals/mammal_kangaroo.html.

Anonymous, January, 2000. "Southern Game Meat" (On-line). Accessed October 9, 2001 at http://www.sgm.com.au/index.htm.

Anonymous, September 22, 2001. "Western Grey Kangaroos" (On-line). Accessed October 8, 2001 at http://www.kangaroocenter.com/westerngrey.html.

Arnold, G., D. Steven, A. Grassia. 1990. Associations between individuals and classes in groups of different size in a population of western grey kangaroos, Macropus fuliginosus. Australian Wildlife Research, 17: 551-562.

Bennett, A., e. Menkhorst. 1995. Mammals of Victoria. Oxford: Oxford University Press.

Coulson, G. 1993. Use of heterogeneous habitat by the western grey kangaroo, Macropus fuliginosus. Wildlife Research, 20: 137-149.

Poole, W. 1995. Macropus fuliginosus. R Strahan, ed. Mammals of Australia. Washington, D.C.: Smithsonian Institution Press.