Perception Channels: tactile ; chemical
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.
US Federal List: endangered
CITES: appendix i
IUCN Red List of Threatened Species: near threatened
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).
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).
Positive Impacts: ecotourism
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).
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).
Biogeographic Regions: australian (Native )
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 ).
Terrestrial Biomes: desert or dune ; savanna or grassland
Average lifespan
Status: captivity: 14.4 years.
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).
Range mass: 2 to 9 kg.
Range length: 480 to 650 mm.
Sexual Dimorphism: male larger
Other Physical Features: endothermic ; bilateral symmetry
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).
Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate); sexual
Average birth mass: 0.5 g.
Average gestation period: 31 days.
Average number of offspring: 1.1.
Average age at sexual or reproductive maturity (female)
Sex: female: 541 days.
