Small Mammal Survey

*Small Mammal Survey*

The story so far: Friends Of Grampians-Gariwerd have a grant to involve the public in research, and to educate them as to its importance. We did a substantial survey using the ‘Hair Sampling Tube’ method, and we have written it all up in a set of A3 books, one of which will be on a table in the Visitor Centre and the others will be loaned around to people interested in what we have done as a community research programme.
Our final activity was to invite Hans Brunner up for a public lecture on hair tubing, which was greatly appreciated.

Hans takes three views of any hair samples supplied, (refer pictures above (bandicoot) and below (tiger quoll).

FIRST: a cross section, shown in the upper left of the picture, this is usually the most easily identified.
SECOND, a whole hair view, shown on the far right of the picture, giving a longitudinal view through the hair. This is usually the second most useful view.
THIRD, he makes a cast of the outside of the hair, shown along the bottom, which show the scale pattern of the hair.

Step 1- Threading hair through the slide

Step 2 Position the slide under the microscope

Step 3 Examine or photograph the slide

The result with black wallaby hair

*BARBARA TRIGGS*
Barbara Triggs lives with her retired husband in an enclave of the Croajingalong National Park on the Mallacoota lakes, about 12 km by water to Mallacoota, about 40 km by gravel road to Genoa. She is the author of ‘Tracks, Scats and Other Traces, A Field Guide to Australian Mammals’, the main resource in that field. Barbara has analysed the hairs we collected this year. A busy person, who received us warmly, fed us coffee, and provided us with much knowledge. She showed us how the analysis is actually done. There are three views which can be made to analyse hairs. (This is the method pioneered by Hans Brunner)
The first one is to get a bunch of hairs, put them on a slide with some glycerine and look at them. The pattern, and the ratio of the medulla, (the dark centre) to the diameter of the whole hair are very characteristic, and according to Barbara are often enough to get to a near certainty.
The next is more laborious, and involves pulling a bunch of hairs through a small hole in an aluminium plate, and then trimming both sides flush with a sharp razor blade. This gives cross sections, which have a very characteristic shape and colour.
The third is to make a cast. To do this you put a thin smear of Aquadhere on a glass slide. Then carefully place one or more hairs in that. When the glue has set enough to become clear, you pull the hairs out, and you have a cast which shows the scale pattern on the outside of the hair. In difficult cases this third view may be the decider, but it is not often required.
We then discussed the future of ‘the book’. How can we do hair analysis without plates to compare our samples with?
Hans Brunner does not want to reprint it, it needs revision, and anyhow the first edition sat on the shelves for a decade or more until interest in the method started to grow, so it is not a publisher’s delight. Barbara is interested in producing a CD version, and a contact of hers is trying to get a grant to get that underway. In the meantime, as an act of trust and generosity she has lent us a set of slides of cross sections of hair of all native animals we are likely to find in the Grampians, which we are allowed to scan on to our computer, and use.

Black (Swamp) Wallabies

*BLACK (SWAMP) WALLABIES*

Matthew Wood did his PhD study at Deakin University of the Red-Neck and the Black Wallabies in the Grampians. Project Title: Habitat use and potential for competition in sympathetic populations of Red-necked Wallabies and Black Wallabies.

The Black Wallaby, Wallabia bicolor, was first reported in the Grampians in March 1979 and has since established populations to become widespread throughout most of the Park. The presence of the Black Wallaby in the Grampians may have some serious implications for existing populations of Red-necked Wallabies, Macropus rufogriseus, through interspecific competition.

In the Winter 1998 edition of the FOGG Newsletter, readers will recall the article by Matt Wood, Deakin University PhD student, setting out his plans to research the “Habitat use and potential for competition in sympathetic populations of Red-necked and Black Wallabies.” Hard pressed as he was with his project, Matt gave us the following report on his progress.

To date I have caught and attached radio collars to a further six Red-necked Wallabies (3 males & 3 females) and four Black Wallabies (3 males and 1 female). I am still trying to catch another two female Black Wallabies to collar and radio-track for the coming winter and summer.

Over the last 12 months data collection has been conducted on a monthly basis focusing on radio-tracking, vehicle surveys and pellet counts. Seasonal home range locations of radio-tracked wallabies have been recorded for eight Red-necked Wallabies (4 males & 4 females) and six Black Wallabies (3 males & 3 females). These wallabies have recently been caught using a tranquiliser gun so that their collars could be removed and attached to another group of wallabies so that further data can be collected in the forthcoming year.

Hopefully I’ll be lucky next month.

Vehicle surveys have been conducted at least six times per month since July 1998 along a 12.5 km section of road selected to sample the different habitats within the study site. These surveys will continue until May 2000. The data will be analysed to determine the density of wallabies in each habitat.

Bats

Lindy Lumsden some years ago came to the conclusion that almost nothing was known about the Australian Bats, and she decided that she would try to do her bit to improve on that. We had the good fortune to be able spend an evening with her while she explained to us about bats, while doing a survey of what bats were present.

We held this evening in the vicinity of a fire dam, some 5 km from Halls Gap. We had about 20 people there, mainly FOGS members, with some visitors who had seen our notices. Lindy uses a number of devices. In the pictures we are watching her assembling a Harp Net, which consists of fine fishing lines stretched vertically over an aluminium frame. This is put up about half a metre above the ground, and when a bat hits the lines it slides down the lines and come to rest in a padded canvas bag, where it sits perfectly quietly until collected to be inspected and have its vital statistics recorded. We also put up a mistnet, but that needs constant supervision, because any bat entangled in the mistnet needs to be released reasonably promptly.

A lot of bats can be identified by their sounds, so we had an idea what we might catch before we looked in the nets. In fact we identified the white striped bat by its noise only as it is a fast high flying bat, it did not come down low enough to be caught.

Time then came to sort our catch. We caught:
* 18 Little Forest Bats (Vespadelus vulturnus) (15 females, 3 males)
* 5 Large Forest Bats (Vespadelus darlingtoni) (all females)
* 3 Lesser Long Eared Bats (Nyctophilus geoffroyi) (1 female, 2 males)
* 2 Gould’s Wattled Bats (Chalinolobus gouldii) (1 male, 1 female)
* White-striped Freetail Bat (Taladira Australis) was heard overhead but not caught.

We then gathered around for a lecture while the bats collected themselves. Lindy has a frequency translator attached to a notebook computer, which collects the bats’ hunting noises, and divides them by 16 (the frequency that is). These are then displayed on the screen, and can be played back through a loudspeaker. As the bats squeak between 20 and 60 kilohertz, we can hear them at the lower frequency. This was an absolutely riveting experience. We could hear the hunting noise of a bat, and as we looked up at the darkling sky, we suddenly saw the silhouette overhead.

We then had a chance to look at our bats. They were beautiful, quite relaxed, and allowed us to have a good look. Lindy had been inoculated against the virus the bats may be carrying; we used gloves when looking at them. The females were all lactating, so would have had young back in the tree hollows. These species only breed once a year, with the young born in late November – early December. I think the bat Lindy is holding here is a Large Forest Bat, but I will have to check with her. Finally we were all equipped in turn with gloves and given a bat to admire and release.