When a gorilla group’s silverback is close to the end of his reproductive years, females face a dilemma: Should they stay with him until he dies or leave him for another male? A team of researchers from the Max Planck Institute of Evolutionary Anthropology has now found that both strategies bear its costs: females face
When a gorilla group’s silverback is close to the end of his reproductive years, females face a dilemma: Should they stay with him until he dies or leave him for another male? A team of researchers from the Max Planck Institute of Evolutionary Anthropology has now found that both strategies bear its costs: females face reproductive costs of staying… Phys.org – latest science and technology news stories
Downtime Down Under – Koala in the Wild on Raymond Island
Image by antonychammond(comp probs – way behind) The koala (Phascolarctos cinereus, or, inaccurately, koala bear is an arboreal herbivorous marsupial native to Australia. It is the only extant representative of the family Phascolarctidae and its closest living relatives are the wombats, which comprise the family Vombatidae. The koala is found in coastal areas of the mainland’s eastern and southern regions, inhabiting Queensland, New South Wales, Victoria, and South Australia. It is easily recognisable by its stout, tailless body and large head with round, fluffy ears and large, spoon-shaped nose. The koala has a body length of 60–85 cm (24–33 in) and weighs 4–15 kg (9–33 lb). Pelage colour ranges from silver grey to chocolate brown. Koalas from the northern populations are typically smaller and lighter in colour than their counterparts further south. These populations possibly are separate subspecies, but this is disputed.
Koalas typically inhabit open eucalypt woodlands, and the leaves of these trees make up most of their diet. Because this eucalypt diet has limited nutritional and caloric content, koalas are largely sedentary and sleep up to 20 hours a day. They are asocial animals, and bonding exists only between mothers and dependent offspring. Adult males communicate with loud bellows that intimidate rivals and attract mates. Males mark their presence with secretions from scent glands located on their chests. Being marsupials, koalas give birth to underdeveloped young that crawl into their mothers’ pouches, where they stay for the first six to seven months of their lives. These young koalas, known as joeys, are fully weaned around a year old. Koalas have few natural predators and parasites, but are threatened by various pathogens, such as Chlamydiaceae bacteria and the koala retrovirus, as well as by bushfires and droughts.
Koalas were hunted by Indigenous Australians and depicted in myths and cave art for millennia. The first recorded encounter between a European and a koala was in 1798, and an image of the animal was published in 1810 by naturalist George Perry. Botanist Robert Brown wrote the first detailed scientific description of the koala in 1814, although his work remained unpublished for 180 years. Popular artist John Gould illustrated and described the koala, introducing the species to the general British public. Further details about the animal’s biology were revealed in the 19th century by several English scientists. Because of its distinctive appearance, the koala is recognised worldwide as a symbol of Australia. Koalas are listed as Vulnerable by the International Union for Conservation of Nature. The Australian government similarly lists specific populations in Queensland and New South Wales as Vulnerable. The animal was hunted heavily in the early 20th century for its fur, and large-scale cullings in Queensland resulted in a public outcry that initiated a movement to protect the species. Sanctuaries were established, and translocation efforts moved to new regions koalas whose habitat had become fragmented or reduced. The biggest threat to their existence is habitat destruction caused by agriculture and urbanisation.
Raymond Island (Gunai/Kurnai language: Bunjil-baul) is a small island in the Gippsland Lakes in eastern Victoria, Australia, about 300 km (190 mi) from Melbourne. The island is approximately 6 km (3.7 mi) long by 2 km (1.2 mi) wide, and is just 200 m (660 ft) off the coast, across from the town of Paynesville. The island is named after William Odell Raymond, originally a magistrate from New South Wales who established himself as a squatter in Gippsland in the 1840s.
Raymond Island is well-known locally for its large koala population, originally introduced to the island in 1953, and for the Raymond Island Ferry, a chain ferry that links the island to Paynesville on the mainland.