Recent studies shed light on the alarming situation faced by the platypus (Ornithorhynchus anatinus), a water-dwelling animal endemic to Australia, in the aftermath of the 2019–20 Black Summer bushfires. Despite their aquatic habitat, these unique creatures are seeing a decline in their population post the devastating fires. This article delves into understanding these implications and the role of environmental DNA (eDNA) in detecting platypus presence.
About Platypuses
Platypuses have characteristics that make them uniquely Australian. Their bodies are streamlined, broad and flat-tailed and covered with dense waterproof fur that acts as excellent thermal insulation. The webbed feet assist them in swimming, and the electroreceptors in their bills help them find food in rivers and streams. Classified under monotremes, a separate order of mammalian species known for laying eggs, platypuses also showcase a unique trait among mammals – males possess a venomous spur on their ankles, primarily used during the breeding season. The venom, while not lethal, can cause severe pain and swelling in humans.
Habitat and Distribution of Platypuses
Platypuses inhabit a wide range of Australian landscapes and freshwater systems. From tropical rainforest lowlands, northern Queensland plateaus to cold, high-altitude regions like Tasmania and the Australian Alps, platypuses cover a broad geographical distribution.
Seasonality, Behavior, and Feeding Habits of Platypuses
Active throughout the year, platypuses show a preference for twilight and nighttime activity. They spend most of their time in riverbank burrows or tucked away in rocky crevices and stream debris. At night, their diet mainly constitutes a wide variety of aquatic invertebrates like insect larvae, shrimps, swimming beetles, water bugs, worms, and tadpoles. Larger prey is captured individually to be consumed afloat on the water surface.
Predators and Threats to Platypuses
Platypuses find themselves threatened by a variety of predators, including crocodiles, carpet pythons, eagles, and large native fish. Land-based threats like foxes, dogs, and dingoes are also at play. They can also suffer from ectoparasites, tick species, and fungal infections. The International Union for Conservation of Nature (IUCN) lists them as ‘Near Threatened.’
The Role of Environmental DNA (eDNA)
DNA, or deoxyribonucleic acid, carries the biological instructions needed for building and maintaining organisms. Environmental DNA (eDNA) refers to nuclear or mitochondrial DNA that organisms release into their environment. This could include secreted feces, mucus, and gametes, or shed skin and hair. In aquatic settings, currents and hydrological processes dilute and distribute eDNA. However, eDNA only lasts about 7–21 days, depending on environmental conditions.
Last Modified: February 22, 2024