Platypus(Ornithorhynchus anatinus)
They are sometimes called the Duck-Billed Platypus. The platypus is a most unusual animal. They have thick fur that keeps them warm underwater. Most of their fur is dark brown, with a lighter patch near their eyes, and a lighter color on the underside. On their front feet is extra skin that serves as a paddle when they swim. They walk clumsily on their knuckles in order to protect this webbed skin. Their bill is smooth, flexible and rubbery, and feels like suede. The male features a venomous spike on it back foot which has enough poison to cause severe pain for a human.
Habitat
They are found on Eastern coasts of Australia as well as Tasmania, Flinders and King Islands. There is also small introduced population on Kangaroo Island. Platypuses are restricted to streams and suitable freshwater bodies, including some shallow water storage lakes and ponds.
Diet
They are carnivorous, feeding on annelid worms, freshwater shrimp, insect larvae, and freshwater yabby dug out with its snout from the riverbed or caught while swimming. It carries prey to the surface in its cheek-pouches. Each day it needs to eat as much as 20% of its own weight, so each day it must spend about 12 hours hunting for food.
Breeding
Platypuses are polygynandrous, and males and females both have several partners. Females can first mate at the age of 2, but some don't until they are 5. The breeding season is between the Australian winter months of June and October. When females are ready to give birth, they burrow into the ground to seal themselves off in one of the rooms. She lays 1 or 2 eggs and keeps them warm between her rump and tail. The eggs hatch after about 10 days. The little bean-sized young remain nursing for 4 to 5 months. They stay in their burrow until they gain about 80 percent of their adult weight, around 6 months.
Population
According to the IUCN Red List, they are classed as Near Threatened(NT). This may have changed now as they were last assessed on 22nd April 2014. The number of mature individuals is estimated at 30,000-300,000 and their population trend is decreasing.
Threats
Currently, the predominant threat to the species on the mainland is reduction in stream and river flows due to recent successive droughts, stream regulation, and extraction of water for agricultural, domestic, and industrial supplies. It is also at risk from the opposite extremes associated with climate change – extensive flooding both in space and time associated with recent tropical cyclones that have resulted in increased mortality and all but eliminated recruitment in 2006 over a substantial part of the species’ northern range. Habitat modification due to bank erosion and stream sedimentation (as a result of poor land management practices in agriculture, forestry, and urbanization) are also of great concern. In the case of urban streams, Platypus populations may be adversely affected by poor water quality (in the form of suspended solids and nutrient enrichment), contamination of sediment by heavy metals and entanglement in or ingestion of plastic, rubber and metal litter. Accidental drowning in nets and traps set for fish and crustaceans has the potential to impact Platypus distribution and abundance in all parts of its range, especially in small streams where populations may be critically small. Populations in Tasmania are affected by mucormycosis. Across its range, the Platypus is also subject to predation by the introduced Red Fox, dogs and cats.
Conservation
Conservation of the Platypus is limited to its listing as a legally protected species in all states in which it occurs and its incidental inclusion in some national parks and reserves. Legislation prohibiting or controlling problematic fishing activities has been enacted in New South Wales and Victoria, but regulations concerning illegal netting and trapping are often poorly enforced. The most widespread field monitoring program for the species is in Victoria (Australian Platypus Conservancy). There are also a few system-specific studies in other states and community-based reporting of anecdotal occurrences of the species to a variety of institutional and private databases. Still more information about population numbers and monitoring are crucial, especially for a long-lived species such as the Platypus where a lack of recruitment can be masked until a dramatic population crash occurs as adults reach the end of their lifespan.
Population studies of fragmented populations should be a research priority, together with studies to help verify the current distribution and baseline population parameters in areas where the species has declined. Once the Platypus becomes extinct in a river system, the likelihood of its re-colonising that system without human intervention is minimal. One reintroduction program is underway in a single fire-affected stream in Victoria (Australian Platypus Conservancy).
Some populations of Platypuses have exhibited antibodies to Leptospirosis, probably transmitted via cattle, but no clinical symptoms have been observed. Mortality from an ulcerative dermatitis caused by Mucor fungus, however, has been recorded across many river systems in Tasmania. There is currently limited investigation of this disease, which should be a research priority both in that state and on the mainland where the fungus is also found.