Environment

Koala Facts: Animals of Oceania

These marsupials sleep twenty hours yet still find time to consume as much as 1.5 pounds of eucalyptus leaves per day.

Physical Description

With their cute and cuddly appearances, Koalas (Phascolarctos cinereus) even though inaccurately tagged as "Koala bears", are in no way related to that group of mammals. In fact, Koalas are actually marsupials, with females possessing abdominal pouches within which they carry their newborn. The average size of Koalas ranges between 23.5 and 33.5 inches (60 and 85 centimeters), with average adult weights of about 20 pounds (9 kilograms). Usually, males have 50% higher weights than do females. The color of these animals varies between a slate grey and a reddish brown on their back, or dorsal, sides. The front, or ventral, part of their bodies is usually covered in whitish fur. These animals are well adapted to life in the trees, with large, sharp claws on both fore- and hind-limbs to latch onto bark, and opposable thumbs on the former to help them curl their fingers tightly around the branches of trees while climbing. Even though their eyesight is quite poor, the large, fluffy ears of these marsupials aid in proficient hearing abilities. The thick, wooly fur of the Koala is an excellent insulator, and keeps the animal comfortable in extremes of temperatures, and also acts as a waterproof coat, repelling and wicking moisture during rainy weather.

Diet

Koalas are herbivorous animals, strongly favouring a diet consisting of Eucalyptus leaves. However, they may also be dependant for food on some other trees like Acacia, Leptospermum, and Allocasuatina, depending upon seasonal availability and their specific geographic location. Koalas are highly fussy eaters and, among the 600 species of Eucalyptus trees, only about 30 species are preferred by these creatures. They mostly select plants which have a higher protein content, and concurrently lower fiber and lignin contents. About 1 to 1.5 pounds (454 to 680 grams) of green Eucalyptus matter are consumed by an adult Koala each day. Since the leaves of this plant have high water contents, the female Koalas hardly need to resort to other sources of water to meet their water needs. The larger, male Koalas, however, need supplemental water source from the ground or from the tree hollows to hydrate their larger bodies and metabolic demands.

Habitat and Range

Koalas are primarily arboreal marsupials who spend most of their time in the branches of the trees, and rarely come down to the ground. The expansive branches of the eucalyptus tree makes an ideal habitat for these animals. Koalas also have the ability to survive in fragmented habitats and areas with low tree density. These creatures are found in the coastal islands, eucalyptus forests, and woodlands of eastern and southeastern Australia, spanning the states of Queensland, Victoria, New South Wales, and South Australia alike. Currently, there is no cause for alarm regarding the numbers of this species, and Koalas have been placed as a species in the "Least Concern" category by the IUCN Red List of Threatened Species due to their widespread distribution. However, certain populations of Koalas still remain vulnerable to human activities that result in habitat destruction, bushfires, and accidental deaths. Thus, conservation efforts implemented by the Australian Government are continuously being undertaken to ensure for the long-term survival of this species.

Behavior

Koalas spend most of their time within a single tree, eating and sleeping on the same one. Since their diet provides very little energy, they may sleep for almost 20 hours a day to conserve whatever energy they acquire from their food. The time they stay awake (usually 4 hours a day) is primarily spent on feeding activities. Koalas spend very little of their daily time in socializing with other individuals of their species. Females mostly make a permanent residence in a tree usually for the duration of their natural life term, while males are more transient, and leave their original trees for others as they mature and search of new territories. The home range of Koalas usually overlap, and it is within these small, close-knit communities comprised of a few, proximately lying trees that the maximum levels of social interaction between Koalas takes place. Combative behavior is often exhibited by males passing by ‘stranger’ males on the ground, and may even involve biting. In extreme cases, a larger male might displace a smaller one from its home in a tree.

Reproduction

Koalas usually mate between December and March every year, during the Australian summer. Males initiate the mating process by attracting females through making bellowing sounds and producing scents. The mating process lasts only a few minutes, as the animals cannot afford to waste energy on long-drawn out mating rituals. The females produce a single baby a year, and sometimes only one every 2 to 3 years. Thus, the rate of population growth among Koalas is quite slow. The young Koalas are called "joeys" like many other marsupials. Koalas are born helpless, hairless, and blind, and remain in their mother’s marsupial pouch until they have matured enough to fend for themselves. For the first six months of life, they will depend on their mothers' milk and warmth for complete protection. After adequate physical development, they start coming out of the pouches, exploring the new arboreal world that surrounds them.

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