In early May this year I helped with Mulligans Flat annual survey of Eastern Bettongs. We worked in teams of three, checking traps for bettongs from 2am until dawn.
Eastern Bettongs are nocturnal, rabbit-sized, marsupials, they kind of look like tiny wallabies. They are incredibly cute, but unfortunately, because we were surveying at night, it was too dark to take photos, but here is a photo that I found on the internet.
The Eastern Bettongs in Mulligans Flat are part of a reintroduction program. Eastern Bettongs have been extinct in Canberra since about 1900, they used to be found in South-Eastern Australia, but now are limited to Tasmania. It is thought that the decline of bettongs on the mainland was due to predation from foxes, hunting, competition with rabbits and livestock, and habitat modification.
In 2012, 17 Eastern Bettongs were reintroduced to Mulligans Flat from Tasmanian populations. Mulligans Flat in North Canberra is a fenced reserve containing critically endangered box-gum grassy woodland habitat, the area had been degraded mainly by over grazing by livestock and kangaroos. Mulligans Flat is set up as a long-term ecological study, it aims to recreate the habitat from pre-European settlement, and improve habitat quality by restoring ecosystem processes. This is where the bettongs come in; bettongs are ‘ecosystem engineers’ they dig the soil to find their favourite food; truffles! The way that bettongs disturb the soil is different to how introduced animals such as rabbits do; bettong digs have many positive effects on the ecosystem. They improve soil condition, encourage water infiltration and disperse fungal spores, all of which are beneficial.
It is often difficult for reintroductions of this type to work, which is why monitoring of the population is so important. The traps we used were baited using oats, peanut butter, and oil (apparently a decent fungi substitute). The bettongs were transferred from the traps into cloth bags to minimise the stress of the assessment process. We then checked for microchips, and microchipped any new individuals, we also took measurements to assess age and overall health such as head length, tail diameter, and weight.
Things are looking positive for the bettong populations; from the 19 traps that my team checked we trapped seven bettongs (and two possums), and they were all in good health! We had to microchip two new individuals, and we also saw two pouch young, one was a tiny pink thing, and the other was covered in hair and almost old enough to leave the pouch! The presence of these new individuals suggested that the population was reproducing well.
From the bettong survey it is estimated that there are now 90 individuals in Mulligans Flat, which is a huge increase from the 17 founders! This gives me hope that the Mulligans Flat project can effectively restore this habitat, and that despite all the damage that humans have done to this land over the past 200 years, with sufficient investment other similar projects could be successful to restore the healthy environment we once had.
Emma Bliss U5014257