The quokka (Setonix brachyurus) is a small, herbivorous marsupial native to Australia. As the only species in its genus and a member of the macropod family, it has gained global recognition for its distinctive, seemingly cheerful expression, earning it the informal title of “the world’s happiest animal.”
Physical Dimensions and Appearance
The quokka is one of the smallest wallabies, comparable in size to a domestic cat. An adult typically weighs between 2.5 and 5.0 kilograms (5.5 to 11 pounds). Its body length, excluding the tail, ranges from 40 to 54 centimeters, and its shoulder height is generally 24 to 33 centimeters when upright.
They possess a stocky build with thick, coarse fur that is typically grizzled brown or grey-brown, often with lighter fur on the underside. The tail is relatively short for a macropod, measuring 25 to 30 centimeters, and is covered with little hair. They have a short, broad head with rounded ears and a small, naked black nose. Their well-developed hind legs allow them to hop efficiently through dense vegetation.
Natural Habitat and Conservation Status
The quokka’s geographical distribution is highly restricted to a small area of southwestern Western Australia. The largest and most secure populations reside on the offshore islands of Rottnest Island (near Perth) and Bald Island (near Albany), where they are protected from mainland predators. Only a few isolated populations remain in protected areas on the mainland.
Quokkas prefer environments with dense vegetation, which offers both food and shelter. These habitats often include dense scrub, thick forests, and swampy areas that provide year-round access to fresh water or moisture-rich plants.
The International Union for Conservation of Nature (IUCN) currently lists the quokka as Vulnerable. While island populations are stable, mainland numbers have declined significantly due to habitat loss from agriculture and housing development. A primary threat to mainland quokkas is predation by introduced species, such as the European red fox and feral cats.
Diet and Unique Behavioral Traits
Quokkas are herbivorous, feeding on a wide variety of plants. Their diet consists of grasses, leaves, stems, seeds, and the foliage of native shrubs. They are primarily nocturnal, foraging for food at night. During the day, they rest in dense, shady cover to avoid high temperatures.
The unique feature that captivates people is the quokka’s apparent “smile.” This look is not an expression of happiness, but a result of their distinct facial structure and relaxed jaw muscles. The upturned corners of the mouth may also be an adaptation to aid in panting and cooling down in the warm climate. These marsupials are generally social, sometimes gathering in groups of up to 150 individuals around water sources.