Endangered Species Friday | Macrotis lagotis
This Fridays (ESP) [Endangered Species Post] I touch up on the Macrotis lagotis, commonly known as the Rabbit-eared Bandicoot identified back in 1837 By Dr Reid. (Image credit unknown, explorer unknown).
The Rabbit Eared Bandicoot is the fifth Australian marsupial that I’ve documented on since establishing the (Endangered Species watch Post), covering now over 403 species of animals (worldwide) in exactly 5 years. From 1965 very little was actually known about the Rabbit Eared Bandicoot, despite the fact it was formally identified way back in the 1800’s.
Unfortunately when scientists eventually managed to re-locate the species, they found the animal was in fact nearing extinction within its endemic wild. Listed then as (ENDANGERED) the species almost went extinct from the 1980’s - 1900’s. Fortunately environmental scientists worked hard to preserve this rather unusual animal. From 1990 the species was still listed as (endangered - and nearing complete extinction within the Australian wild).
Fortunately from 1994-1996 species recovery programs increased populations within the wild. Come 1996 the species was re-listed as (vulnerable). Commonly known as the ‘bilby’, M. lagotis once inhabited some 70% of Australia. Wild populations are now restricted predominantly to the Tanami Desert (Northern Territory), the Gibson and the Great Sandy Deserts (Western Australia), and one outlying population between Boulia and Birdsville (south-west Queensland). The bilby has gone extinct from portions of southern Queensland within the last few decades.
However despite numerous conservation actions that have been aiding and increasing bilby populations, they are now on the decrease; slowly, but surely, for how long though is another story. Endemic to Australia (Northern Territory, Queensland, and Western Australia) its believed there are no fewer than 500 individuals on Thistle Island, 500 in Arid Recovery, 100 in Venus Bay, 200 in Peron, 40 in Scotia, 200-500 in Queensland.
There are fewer than 1,000 individuals in the Northern Territory and 5,000-10,000 in non-reintroduced Western Australia. The global population might be under 10,000 individuals. The species is wide-ranging and patchily distributed. The population estimates of bilbies in the Northern Territory and Western Australia are very approximate, as there are no published numbers in peer-reviewed journals. It is known from aerial surveys that bilby signs (diggings) in the areas where bilbies are persistent occur less than 15 to 20 km apart.
“TEN THOUSAND INDIVIDUALS REMAINING”
Image: Bilby, Australia. Photographer unknown.
Bilby populations are not known to be seriously fragmented, and from what I am aware the species is protected under CITES APPENDIX I (Convention on International Trade in Endangered Species of wild Fauna and Flora).
“WHAT’S WITH THE LARGE EARS?”
You’ll find that many small and even large animals that live within extremely arid and hot countries, and are active during the daytime will host large fan like ears. Without these large cooling like rabbit ears many species of animals wouldn’t be able to radiate heat away from its most important organs - being the brain. Smaller ears would most certainly result in the mammal dying from massive heat stroke, and dehydration. However due to the lack of research on the bilby, we still don’t know for sure if these massive ears do indeed help keep the species cool.
Bilby ears are almost naked, which ‘may be for temperature regulation’, but because the research hasn’t been done we don’t actually know for sure. One thing that scientists studying bilbies do agree on is the variability in behavior between bilby populations living in different conditions around Australia. They’ve adopted different diets, burrows, breeding habits and social networks, and this adaptability has been the key to their survival.
The current bilby distribution is associated with a low abundance or absence of foxes, rabbits, and livestock. Major threats relate to predation from foxes, habitat destruction from introduced herbivores, and changed fire regimes. Predation pressures “from feral cats” and dingoes occurring in association with pastoral practices may be a threat to the bilby. Feral cats have affected the success of reintroduced populations. Additional threats to the bilby include mining and other development, and road mortality.
When: Bilbies are opportunistic breeders waiting until conditions are good, rather than particular seasons.
Where: In the wild, bilbies are now limited to patches of the northern desert areas of NT and WA. and a tiny isolated remnant population in SW QLD. They are also found in sanctuaries and breeding colonies in WA, NSW, SA and QLD.
Other info: The name bilby comes from the Yuwaalaraay people of northern NSW. They are important in Aboriginal culture and were a common food resource. Bilbies live up to 7 years in the wild and 11 years in captivity. They are considered endangered.
WHAT DO BILBIES EAT?
Bilbies are omnivores and eat insects, seeds, bulbs, fruit and fungi. Most food is found by digging in the soil. Big ears quickly detect insect prey, which they catch with their long tongue.
Thank you for reading.
Every Monday and Friday I.A.R.F publishes in the last (6 months of each year) an Endangered Species Post. Furthermore every Wednesday I.A.R.F also publishes investigative articles relating to wildlife, environmental and animal concerns. For more information please subscribe to our news feed for free here www.speakupforthevoiceless.org
Dr Jose C. Depre PhD. MEnvSc. BSc(Hons) Botany, PhD(NeuroSci) D.V.M. Environmental & Human Science.
Endangered Species Monday: Vini peruviana
This Monday’s endangered species watch post (ESP) I document on a rather elusive bird that is rarely spoken about within the conservation theater or among animal rights organisations. Listed as (vulnerable) the species was formally identified by Professor Philipp Ludwig Statius Müller (April 25, 1725 – January 5, 1776) was a German zoologist. (Image V. peruviana, photographer Tara)
Statius Müller was born in Esens, and was a professor of natural science at Erlangen. Between 1773 and 1776, he published a German translation of Professor Linnaeus’s Natursystem. The supplement in 1776 contained the first scientific classification for a number of species, including the dugong, guanaco, potto, tricolored heron, umbrella cockatoo, red-vented cockatoo, and the enigmatic hoatzin. He was also an entomologist.
Despite the birds high population size the Blue Lorikeet-scientifically named as Vini peruviana is under threat from feral cats, accidental introduction of black rats and violent storms that hit the birds native range frequently causing untold damage and catastrophic destruction to the specie habitat. Furthermore the ‘swamp harrier’ remains an all out threat to Blue Lorikeet’s range which has led to wide range species decline. Swamp Harriers predate on the Blue Parikeet mainly due to the birds color.
Endemic to the Cook Islands and French Polynesia, Blue Lorikeet population sizes are declining quite fast of which drastic conservation measures are now required to control feral cats and the accidental introduction of black rats, not forgetting measures to either reduce swamp harriers or introduce a non-endangered prey for the harrier. The last survey which I believe was undertaken sometime back in 2012 showed a ‘global population’ estimated to be at 7,200 to 9,000 individuals. Which is still quite high, however not high enough to stop the species qualifying for the classification of (endangered).
Taking into consideration range and overall total population size (at an estimate) the species falls into the ‘band’ of 2,500 to 9,000 individuals. This equates (exactly) to 1,677-6,666 ‘mature individuals’ rounded to 1,500-7,000 mature individuals. Summarizing; the exact total population size could be as low as 1,500 but no greater than 7,000 mature individuals (which is extremely concerning).
Blue Lorikeet’s have been recorded within twenty of the south-east Polynesia islands, unfortunately on seven of these islands the species has since been declared officially extinct. The species now remains sparsely distributed on some thirteen islands of which is threatened by rats, feral cats and the swamp harrier. We now know the species is situated within the Society Islands (formerly all), the northern atolls of the Tuamotu Archipelago (both French Polynesia), and Aitutaki (Cook Islands).
Image: Blue Lorikeet - Vini peruviana
Within the Society Islands conservation teams estimated that there were some 200-400 individual pairs on the Motu One and Manuae respectively in 1973 , however this may no longer be the case. On the Maupihaa island back in 1999 conservationists that believed the species to be extinct located breeding pairs. In Tuamotus 2006 surveys have shown the following data in relation to population sizes; Kaukura (1,000), Rangiroa (1,000), Arutua (500), Apataki (200) and Tikehau (50).
Meanwhile in Tiamanu Motu in Apataki atoll a minimum 300 individuals were estimated back in 1989 (this sub-population being allegedly smaller than 10 years previously). On Aitutaki, where it was probably introduced, numbers have been estimated at under 500 pairs, 2,400 individuals and 1,000 individuals (2006).
Following the devastation of Cyclone Pat (2010) a further census was undertaken to asses the impacts of freak weather patterns and catastrophic cyclones on the species. Distance sampling surveys on the island of Aitutaki (2011) showed a decrease in population size of exactly 1,400 individuals. That’s quite a substantial decline of individuals caused directly by a single yet destructive cyclone.
Blue Lorikeets depend on coconut palms for nesting and some of its food, and will frequent cultivated areas. They also roost in palm trees, rising at dawn and calling and preening before feeding. They are usually found in small flocks of less than ten birds. They are active birds, feeding on nectar, insects, and ground forage.
Image: Swamp Harrier (Wiki) - . Circus approximans
The species’s extinction from many islands is most likely due to predation by black rat Rattus rattus and to a lesser extent, feral cats Felis catus. Blue Lorikeet’s have gone extinct from Makatea in the Tuamotus could have been accelerated by a particularly violent hurricane. Its range reduction in the Society Islands correlates with the spread of the introduced Swamp Harrier Circus approximans. The accidental introduction of black rats to the islands where Blue Loirkeet persists is a continuing threat to the species. Listed on Cites Appendix II conservation actions are under way with more projects proposed.
Thank you for reading.
Dr Jose. C. Depre
Botanical and Environmental Scientist.