Petrogale xanthopus have a discontinuous range throughout Australia. Specifically, they are found in the states of South Australia (Flinders and Gawler Ranges and the Olary Hills), New South Wales (Gap and Coturaundee Ranges), and Queensland (Adavale Range) (Lyne 1967; Bates 2000).
As their common name implies, yellow-footed rock wallabies live on cliff faces and rocky ramparts on mountain tops. This habitat restricts the species to isolated pockets of rocky outcrops, cliffs, and ridges in semi-arid country. Mulga scrub is the dominant vegetation in these areas but the rocky outcrops also provide a wider diversity of vegetation than is found in surrounding areas, which is essential to their diet (Dawson 1983, National Parks and Wildlife Service, 1999 ).
Petrogale xanthopus are medium-sized wallabies with a stocky build. Their head and body length can range anywhere from 480 to 650 mm, with an average of 600 mm, and their long, un-tapered tails from 570 to 700 mm, with an average of 690 mm. They have large hind feet that are 120 to 170 mm long and are marked with short claws and thick, course pads. They weigh from 6 to 11 kg. Females, like other marsupials, have a well-developed forward opening pouch and four teats. They are also slightly smaller than males. They are greyish above with white fur below, but the ears, legs, and feet are colored rich red to yellow. They have distinct white cheek and hind stripes, a buff-white side stripe, and a brown mid-dorsal stripe from the crown of their heads to the center of their backs. The tail is typically reddish-brown with dark stripes, but is variable (Walton and Richardson 1989; Hornsby 1998; Nowak 1999).
Said to be the most striking of all the kangaroos, P. xanthopus' coloring is extremely noticeable and gets increasingly lighter as one moves down the body, with the head and upper body a brownish-gray color and the rump a brighter gray. They are also characterized by a dark brown streak that runs from the wallabies' ears to their mid-back. This streak connects to brown and "yellow" patches that are found on the limbs. The face has white stripes running down each cheek with the aforementioned yellow coloring behind the ears (Bates 2000).
Given good nutrition and living conditions, Petrogale xanthopus breed all year long. In fact, females ovulate, mate, and conceive within a day of giving birth, making it very common for them to be pregnant 365 days a year. Their estrus cycle lasts from 30 to 32 days and they have a gestation period of 30 to 32 days. The embryo will develop and be born after the removal of the previous young. Pouch life then lasts anywhere from 189 to 227 days. Sexual maturity is reached in males at about 590 days and in females at about 540 days after birth. The litter size is typically one, but twins are not unheard of (Walton and Richardson 1989; Nowak 1999; Bates 2000).
Petrogale xanthopus are thought to be nocturnal, spending their days hidden in rock crevices and caves. They are known, however, to come out for the occasional sunbath, and are sometimes active during the daylight in captivity. Locomotion occurs by jumping from rock to rock. Leaps can measure up to four meters in length. P. xanthopus even have the ability to climb up steep cliff faces and tree trunks (Collins 1973; Nowak 1999; Bates 2000).
Wallabies live in fairly organized societies, in which males compete for hierarchical mating rights. Males also engage in an olfactory courtship ritual with the females. After a female gives birth, mother/young interaction is minimal - the offspring is not assisted into the pouch and interaction is limited to cleaning the joey. Once the offspring leaves the pouch, however, the mother and young will communicate by clucking and grunting, play, and will groom each other (Walton and Richardson 1989).
Petrogale xanthopus are herbivores that rely on browsing and grazing. In the wet season, their diet predominantly consists of grasses. As conditions become increasingly dry, the species becomes more dependent on the leaf fall of shrubs and trees. In drought, this leaf fall becomes the staple of P. xanthopus' diet (Hume 1999).
Yellow-footed rock wallabies also have the unique ability to consume over ten percent of their body weight in water in about seven minutes. This allows them to utilize the infrequent summer rainstorms that occur in the region as opposed to the salty creek runoff that other species in the area rely on (Hornsby 1998).
Humans have hunted Petrogale xanthopus and macropodids in general both for their meat and skins and for sport, though this species is now protected from hunting by law (Walton and Richardson 1989; Earth Sanctuaries Ltg. 2000).
More importantly, wallabies, especially rare and beautiful ones such as P. xanthopus, are one of the most eagerly sought attractions by foreign tourists. Although they are difficult to see in the wild, they are easy to keep in zoos and national parks. Although their exportation is strictly controlled, they provide an important source of income for Australia (Walton and Richardson 1989). (Earth Sanctuaries Limited, 2000; Walton and Richardson (eds), 1989)
With the introduction of feral goats and domestic sheep and subsequent move of Petrogale xanthopus down the mountains in search of food and water (see the "Conservation" section below), pastoral lands, crops, and fences could be in danger of suffering damage from overgrazing. Because yellow-footed rock wallabies are so limited in number and distribution, however, significant damage is unlikely (Walton and Richardson 1989; ESL 2000).
Yellow-footed rock wallabies' numbers are steadily falling. Today, there are an estimated 5,000, in comparison to 12,000 ten years ago. This is predominantly due to the heavy infestation of feral goats and domestic sheep in their niches. Goats and sheep are two of the few species that can invade their relatively safe, rocky environment. Because they share the same diet as wallabies, goats and sheep have created unprecedented competition for resources and have forced them to move elsewhere for food and water. Wallabies have also suffered predation from non-native predators, such as foxes. Historically, P. xanthopus have also been hunted both for sport and for agricultural reasons (Nowak 1999; ESL 2000).
This species is listed in Appendix I of CITES, so international trade in animals or parts is illegal. It is listed as Endangered under the U.S. Endangered Species Act. The IUCN rates it "Lower Risk/near threatened" on the Red List.
George Hammond (editor), Animal Diversity Web.
Allison Steinle (author), University of Michigan-Ann Arbor, Phil Myers (editor), Museum of Zoology, University of Michigan-Ann Arbor.
Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.
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.
uses smells or other chemicals to communicate
in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.
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.
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.
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
reproduction that includes combining the genetic contribution of two individuals, a male and a female
uses touch to communicate
A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.
A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.
A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.
Australian National Parks and Wildlife Service, 1999. "Threatened Species Information, Yellow-footed Rock Wallaby" (On-line). Accessed January 2, 2003 at http://www.npws.nsw.gov.au/wildlife/thr_profiles/yfrckwal.pdf.
Bates, D. 2000. "Yellow-footed Rock Wallaby" (On-line). Accessed March 19, 2001 at http://whozoo.org/Intro98/dewobate/dewobates1.htm.
Collins, L. 1973. Monotremes and Marsupials: a Reference for Zoological Institutions. Washington: Smithsonian Institution Press.
Dawson, T. 1983. Monotremes and Marsupials: the Other Mammals. London: Edward Arnold Publishers Limited.
Earth Sanctuaries Limited, 2000. "Yellow-footed Rock Wallaby" (On-line). Earth Sanctuaries Online. Accessed March 19, 2001 at http://www.esl.com.au/rockwal.htm.
Hornsby, P. 1998. "Yellow-footed Rock Wallaby Fact Sheet" (On-line). Accessed April 3, 2001 at http://psychology.adelaide.edu.au/members/external/peterhornsby/yfrwfs1.html.
Hume, I. 1999. Marsupial Nutrition. Cambridge, United Kingdom: Cambridge University Press.
Lyne, A. 1967. Marsupials and Monotremes of Australia. Sydney: Angus and Robertson.
Nowak, R. 1999. Walker's Mammals of the World. Baltimore and London: John Hopkins University Press.
Walton, D., B. Richardson (eds). 1989. Fauna of Australia. Mammalia. Canberra: Australian Government Publishing Service Vol. 1B x pp.401-1227.