“Extinction – Just how bad is it and why should we care?” is an interesting article, written by Deakin University Ecology Lecturer, Euan Ritchie. He makes the point that 99% of species that have ever existed are now extinct, and at this time (the Anthropocene) species are becoming extinct at between 1,000 and 10,000 times the ‘usual’ or background levels. We will be looking at two local species that have been severely impacted by human activities in Victoria.
The Orange Bellied Parrot (Neophema chrysogaster) and the Eastern Barred Bandicoot (Perameles gunnii) are both threatened species that existed in much larger numbers prior to European colonization in Victoria. The OBP is now classified as “critically endangered”, as less than 50 individuals have been recorded in their native habitat. The EBB is in an even worse position, listed as “extinct in the wild”, with only three captive populations surviving in the state, although a sub-species still exists in the wild in Tasmania, where there are no foxes.
The Orange Bellied Parrot (OBP) is a small, migratory parrot (a bit larger than a budgerigar) that is very similar in appearance and behaviour to several other parrots of the same genus (the blue-winged parrot, the elegant parrot and the rock parrot). It is distinguished from these other birds by it’s brighter colour, orange belly in the males and a distinctive call. In summer it occupies coastal woodlands in the SW of Tasmania (in and around Melaleuca), where it nests in tree hollows in eucalypts and feeds on the button grass plains. The female OBP lays 4-5 eggs in October to January. In late March/April this courageous little bird flies across Bass Strait, island hopping, to the southern coast of the mainland, including SA, SW and Gippsland. This is where the OBP spends the colder winter months, feeding on samphire of the salt marsh flats and sheltering in the woolly tea tree scrub.
The Eastern Barred Bandicoot (EBB) is a grey/brown marsupial of about 800grams and 40cm in length (including it’s tail) – a little smaller than a rabbit. It has a long nose and ears, with several off-white stripes across it’s rump. It leaves funnel shaped burrows when it is digging for it’s food, including worms, invertebrates, fungi and grasses. In a good season the female can produce up to five litters a year, with three offspring in each litter. The young are born at just 12 days, about the size of a small jelly bean, and climb into the backwards facing pouch, where they spend the next 6 to 8 weeks. They then spend another two weeks in the nest before leaving for a solitary life. The Eastern Barred Bandicoot used to be widespread across western Victoria, as far as the SA border, occupying native grasslands and grassy woodlands.
The main threats to both the OBP and EBB are habitat destruction (land clearing due to agriculture and development) and introduced species (foxes and feral cats are predators of both species). In addition, both species have reached very low numbers (about 40 EBB were discovered at the Hamilton tip before they became extinct in the wild, and there are only 36 wild OBP known to exist at the 2011/12 survey). Such small numbers in a population increase the chances of inbreeding and result in low genetic diversity, which makes these species less able to adapt to changes in their environment and more vulnerable to extinction.
As well as habitat destruction, introduced species and low genetic diversity, the OBP is vulnerable to a disease (Psittacine Circoviral Disease) and stochastic events – random disasters, such as storms during migration, bush fires in their breeding habitat etc.
Both species have been listed on the Victorian List of Threatened Vertebrates and have a co-ordinated management plan that includes the following strategies:
- Captive Breeding Program (to maintain a viable population in captivity to allow re-introductions into suitable protected habitats)
- Habitat Protection and enhancement (Protecting remnant habitats and revegetation with appropriate flora)
- Introduced species control (feral cat and fox baiting/shooting, as well as fences to exclude these predators from the habitats)
- Monitoring and Research programs (collecting quantitative and qualitative data to increase the reproductive and reintroduction success of these species)
- Education programs (increase public awareness about the plight of these species and how they can be protected)
Your task this week is to produce a written report, multimedia presentation or presentation to the class about either the OBP or the EBB, using the task sheet that has been emailed to you. A draft copy is due this Friday (10th May). There are three parts to the task (1) the characteristics of the species and it’s habitat (2) the threats to this species and (3) how these threats are managed and if these strategies have been effective. Make sure you use at least five reliable and up to date references and list the ones used in a Bibliography or References section.
Orange Bellied Parrot Resources:
Wikipedia – Orange Bellied Parrot
Parks and Wildlife Service Tasmania – orange bellied parrot
Birdlife Australia – Orange bellied Parrot
Australian government department of the Environment and Heritage – Saving the Orange Bellied parrot
Zoos Victoria – Orange Bellied Parrot
National Recovery Plan for the Orange Bellied Parrot
Flora and Fauna Guarantee Action Plan - Orange Bellied Parrot
YouTube video – Saving the Orange Bellied Parrot
Act Wild for the Orange Bellied Parrot from Zoos Victoria (video)
Eastern Barred Bandicoot Resources:
Parks and Wildlife Service Tasmania – Eastern Barred Bandicoot
Zoos Victoria – Eastern Barred Bandicoot
ABC Vodcast – Saving the Eastern Barred Bandicoot
Melbourne Museum – Eastern Barred Bandicoot
Australian Government department of Sustainability, Environment, Water, Population and Heritage - Eastern Barred Bandicoot
Flora and Fauna Guarantee – Eastern Barred Bandicoot
Act Wild for the Eastern Barred Bandicoot from Zoos Victoria