This is the last post in this series, in which I have been comparing the fortunes of rare birds as they were in 1973 (from a book published then) with how they are now. Today I have selected from the book five birds from Australia and nearby islands to complete our tour of the world. If you would like to read the previous installments do click on the links here: 1 – 2 – 3 – 4 – 5 – 6.
Cape Barren Goose – This dainty goose is found mostly in South-Eastern Australia and offshore islands there, as well as a smaller population in western Australia. In the book it is described as one of the rarest geese on Earth with less than 5000 individuals left, it states the reasons for this are largely hunting (the geese damage crops) and loss of breeding areas to grazing pasture. It says they breed mostly on islands in the Bass straight, feeds on grass and is rarely found on water, it can also drink salt water – enabling it to survive on the islands. Its fortunes seem to have changed considerably for today it is classified as ‘Least Concern’ due to its large range and stable population which currently numbers 16-18000 birds. Apparently the geese have adapted to tolerate agricultural land and have been introduced to New Zealand and it seems to have expanded its range on the mainland of Australia.
Orange-bellied Parrot – This exotically coloured bird winters on the southern coast of mainland Australia, near the Bass straight, in the summer it migrates to Tasmania to breed. The book doesn’t give a lot of information on this bird except that it was once thought to be extinct but may now be recovering its numbers on isolated islands off Tasmania. If only that were true. This lovely species is currently Critically Endangered with only one known breeding site and a population of less than 50 birds. There are more individuals in captivity than in the wild (around 170) with the wild population expected to go extinct in 5 years. There is a captive breeding population in Australia with birds at multiple sites, it is hoped more birds can be taken from the wild to bolster the programme with the intention of raising a viable population for eventual release. Reasons for decline are many – habitat fragmentation, competition for food and nest sites, disease and introduced predators.
Noisy Scrub bird – Probably the simplest name for a bird ever; it has a noisy call, it lives in scrub (In south-western Australia) and it is a bird. This small brown creature is described in the book as having ‘…poor reproductive powers, and so is very rare.’ a very simple and incorrect explanation of its scarcity. This bird was actually believed extinct until 1961 when a population was rediscovered, since then it has been the subject of translocations in order to start new populations and extend its range. It was recently upgraded from Vulnerable to Endangered as its population, despite best efforts, is only 1,500-2,300 individuals – largely due to a series of wildfires in its habitat and predation by non-native predators, it is declining still.
Abbott’s Booby – This is an interesting one, a bird in its own genus and considered separate from all other Gannets and Boobies, it is confined to breeding entirely on Christmas Island in the Indian Ocean (an Australian territory). The book claims a population increase between the 40’s and 60’s but a decrease was underway (from 2000 individuals) by the time of publication, phosphate mining on the island is given as the cause. Today the Abbott’s Booby is listed as ‘Endangered’ with a (declining) population estimate of 9000 individuals – bearing in mind that just half of these are mature and of those only 2,500 pairs breed at any one time as pairs do not breed in consecutive years. As the birds nest in trees they have been badly affected by past logging for phosphate mining, which is still going on. They are sensitive to habitat degradation and the invasive yellow crazy ants have damaged trees, the local ecosystem and are reported to have even predated nestlings.
Kagu – This strange-looking species is an oddity amongst birds, it is classed in its own family and its closest genetic relative is the Sunbittern of South America – which looks nothing like it. It is endemic to New Caledonia, an island group in the south Pacific, off the eastern coast of Australia, and is mostly flightless. The book claims it was limited to just 40 square kilometres in the mountain forests and was under threat from introduced predators such as dogs and rats and that they were trapped for their feathers to go on hats. At the moment the Kagu is Endangered with a population of just 350-1,500 birds, however it seems to be widespread and stable thanks to some decrease in dog hunting – the major threat to the species. Its forest habitat is also under risk of increasing erosion by fires and mining. Despite the low population the outlook seems hesitantly positive as long as the forest is protected and hunting is adequately controlled (or stopped altogether).
So a mixed bag today with some interesting species, throughout all of this series though the overarching threat to the majority of the species covered has been habitat loss or introduced non-native species. Some have not improved their chances at all since the 70’s, either staying the same or getting worse, but some have bounced back remarkably. The constant assault on the natural world can seem insurmountable – yet on the flip-side my research has revealed astonishingly committed teams fighting to save these species from extinction – often successfully, it is good to know someone cares.