The guest speaker for the June meeting was Dr. Brian Chambers from the University of Western Australia and the topic was Fauna Underpasses and the Brush-tailed Phascogale, a UWA Research Project. It has become common practice to install underpasses to help reconnect populations of fauna that have been fragmented by major highways. However, the cost of installation is not insignificant and to find out if they represent a sound investment Dr. Chambers and his team have been contracted by Main Roads WA to investigate whether these underpasses are achieving the desired result.

The research has been conducted on a number of reserves within the Kwinana, Rockingham and Mandurah areas. These are Marlee Reserve near Mandurah; Paganoni Swamp Reserve; Lakes Walyungup and Cooloongup and the Spectacles, with the presentation focusing on the last three in particular. The research involves a combination of trapping (to gain information on what species are present and in what numbers) and motion sensitive infra red cameras together with micro-chip readers. There have been four trapping programmes in Paganoni, two in Walyungup and two at the Spectacles. 

At Paganoni there are 5 underpasses on the reserve’s eastern boundary where the Kwinana freeway extension has split Paganoni from bushland on the eastern or Keralup side. Trapping has captured four Brush-tailed Possums on two occasions but captured 11 in the most recent trapping programme – an indication of a sharp rise in numbers, and when extrapolated out suggests that the reserve supports over two hundred of the possums. Other marsupial captures include the Brush-tailed Phascogale, the Southern Brown Bandicoot (Quenda), especially on the Keralup side of the freeway, and excitingly there have been two separate captures of Chuditch, one in Paganoni in Autumn 2010 and the other in Keralup in Autumn 2012. Larger reptiles include Western Bobtails, Gould’s Sand Monitor, Heath Monitor and Black Headed Monitor (an arboreal monitor).

There are underpasses under Safety Bay Road between Lake Cooloongup Reserve and the Lake Walyungup Reserve. Captures at these two reserves include Quenda (15 – 20 per week), Bobtails, Western Blue Tongues and Black rats (97 per week).

At the Spectacles there were originally three underpasses but only one remains in a suitable condition. Captures here include Quenda and Brush Tailed Possums, which is considered unusual as there are no large trees.

Dr Chambers showed photographs taken by the cameras. At Paganoni these showed a Bobtail, a Kangaroo squeezing through a small underpass, foxes, rabbits and mice.

At Walyungup all photographs showed feral animals, foxes, rats, mice and four different feral cats.

At the Spectacles the camera captured a Bobtail, a fox, a cat and a rat plus many mice.

This research has showed that native animals will use the underpasses but feral animals are obviously a problem.

The Brush-tailed Phascogales, Phascogale tapoatafa tapoatafa, in Paganoni have been the subject of further research. In WA this species is classified as rare or likely to become extinct. Brush-tailed Phascogales are small marsupials, weighing between 110 and 310 grammes and measuring between 310 – 500mm head to tail. Suitable habitat is open woodland with hollow bearing trees. Their diet consists of invertebrates, nectar, small birds and small mammals. Females have a lifespan of three years but males only live 11 months. They breed in May to July with females bearing 3 to 8 young. Males die off after one breeding season. Threats to the species include habitat loss, modification or fragmentation, dieback, wildfires and drought.

The trapping programme has had varied success, in April 2010 one individual was caught, followed by 7 in 212 trap nights in November 2010 and 2 from 332 trap nights in March 2011. There has now been a change in approach. Nesting boxes that specifically target the Phascogale have been installed throughout the reserve. The boxes are installed with the small entrance at the rear close to the tree trunk. Half of the boxes have nesting material and half do not. The ones with nesting material are preferred, almost half are being used. Proof of their success was obtained during a recent check when one was found to be occupied by a female with 7 recently born young. This is very early for young to be born. The box was full of shredded bark, which is typical for females in the breeding season. Out of the breeding season the boxes are less full of nesting material.

Future plans for the research programme include a continuation of underpass monitoring, trapping in late winter and spring, radio tracking of Quendas and monitoring of Phascogales through the breeding season.

There were a number of questions from the audience plus ongoing discussion following the presentation highlighting the level of interest. The fact that this research is taking place in our local reserves and that some rare species are being found there added to our interest. Dr Chambers was thanked for presenting to KRMB and offered best wishes for the continuing research. Colin Prickett