Wombats: furry, subterranean, and occasionally terrifying.

Common wombat (image from http://www.australianmuseum.net.au, © G A Hoye/Nature Focus)

Wombats: moving footstools.

The marsupial family Vombatidae comprises three species: the northern hairy nosed (NHN)(Lasiorhinus krefftii), the southern hairy nosed (SHN) (Lasiorhinus latifrons) and the common (Vombatus ursinus). Adult wombats are around 30cm tall, rectangular in shape (80-100cm long) and weigh between 20 – 35kg (Van Dyck & Strahan 2008). I’ve always thought they look more like footstools than most other animals. The shape is not for putting your feet up after a long day though. Wombats are burrowing machines, and their squat shape is good for moving through tunnels. They also have extra hard patches on the front of their head and on their rump, to compact earthen burrow walls. Common wombats can excavate living quarters in burrows up to 20m long, which can interconnect with other burrows and have several entry/exit points, AND they can have several of these long burrows throughout their home range (McIlroy 2008).

Although wombats have short legs, they can move at up to 40 km/h over short distances if necessary (ref: Australian Museum). Wombats can be aggressive amongst themselves and towards humans, particularly if startled by a person. See here for a story about a wombat attack in 2010.

The NHN wombat is highly endangered, with only a few still living in a moderately secret location near Clermont in central Queensland. The SHN wombat is doing comparatively better, spread across the southern coast of South Australia, and the common wombat is, well, common across Tasmania, ACT, and the eastern parts of Victoria, New South Wales and South Australia.

Why are wombats so cool?

Because they live underground and minimise their exposure to hot daytime temperatures by hanging around in their burrows. They emerge in the evenings to browse on grasses, and have an almost rodent-like dentition as a result of this dietary preference. This lifestyle also means that they have very low energy requirements for an animal of their size. Evans et al. (2003) describe wombats as having an “energetically frugal lifestyle”. The field metabolic rate of a SHN wombat (mean 3,141 kJ/day during the dry season) can be as low as 40% of that expected for a herbivore of wombat size (Evans et al. 2003). They also have very low turnover rates for water, and this combined with their underground lifestyle and slow metabolism means that they are excellent at conserving energy. Which is handy for an animal that, in the case of the SHN wombat, lives in an environment that can be extremely hot and/or dry; and feeds on (often dry) grass of poor nutrition content.

Wombat skull. Note rodent-y dentition. (image from http://www.wombania.com/wombat-pictures/wombat-skull.jpg)

What kinds of parasites do ‘energetically frugal footstools’ have?

Several.

Fasciola hepatica. (Image from:

Fasciola hepatica. (Image from:

Helminths:

Wombats are hosts to the agriculturally-important trematode Fasciola hepatica. Although not an important reservoir host, common wombats do seem to be adversely affected by pathology of F. hepatica infection (Spratt et al. 2008). Wombats are also host to eight species of cestodes (Spratt et al. 1991) including the anoplocephalid Progamotaenia vombati (formerly known P. festiva in wombats, but found to be a species complex across wombats, wallabies and kangaroos (see Beveridge & Shamsi 2009)). Common wombats are also known to host the taeniid Echinococcus granulosus (also known as hydatids), but not in high prevalence and only recorded from parts of Victoria, which indicates that they are not a major intermediate host (see Jenkins 2006).

Ectoparasites:

Wombats are host to 6 species of flea genus Echindophaga. Two species of Lycopsyllalasiorhini and nova, are known only from wombats (Dunnet & Mardon 1974, Gerhardt et al. 2000). Wombats also host ticks, including the widespread species Ixodes tasmani, I. cornuatus and Amblyomma triguttatum, and Bothriocroton auruginans and I. victoriensis (which are both known as ‘wombat ticks’) (Roberts 1970, Gerhardt et al. 2000).

But perhaps the most famous wombat ectoparasite is the astigmatan mite Sarcoptes scabei. Causing the medical (veterinary in this case) condition scabies, this tiny mite has jumped from people to domestic animals to wildlife, and can make life very difficult for affected wombats. Heavy mite infestations can cause hair loss and crusts on the skin of wombats, and can cause severe pathology at the site of infestation, and throughout the body of the affected animal (Skerratt et al. 1999). Wombats with severe infestations can die from a combination of the pathological effects, and from starvation caused by decreased ability to masticate their food, reduced ability to compete with healthy wombats for food, and possibly the increased energy demands caused by the severe infestation (Skerratt et al. 1999).

Final word:

Wombats are good as gingerbread biscuits too.

Homemade marsupial biscuits. L-R: bandicoots, wombats, Tas devils. (photo by me)

References

Beveridge I and Shamsi S (2009) Revision of the Progamotaenia festiva species complex (Cestoda: Anoplocephalidae) from Australasian marsupials, with the resurrection of P. fellicola (Nybelin, 1917) comb. nov. Zootaxa 1990, 1-29.

Dunnet GM and Mardon DK (1974) A monograph of Australian fleas. Aust J Zool Supp Ser 30. 1-273.

Jenkins DJ (2006) Echinococcus granulises in Australia: widespread and doing well. Parasitology International 55, S203-206.

McIlroy JC (2008) Common wombat, Vombatus ursinus. In: Mammals of Australia, eds Van Dyck S, Strahan, R. Reed Books, Sydney.

Skerratt LF, Middleton D, Beveridge I (1999) Distribution of life cycle stages of Sarcoptes scabei var wombat and effects of severe mange on common wombats in Victoria. J Wildl Dis 35, 633-646.

Spratt DM, Beveridge I, Walter EL (1991) A catalogue of Australasian montremes and marsupials and their recorded helminth parasites. Rec S Aust Mus Monogr Ser 1, 1-105.

Spratt DM et al. (2008) Guide to the identification of common parasites of Australian mammals. In: Medicine of Australian Mammals, eds Vogelnest L, Woods R. CSIRO Publishing, Melbourne.

Van Dyck S, and Strahan R (2008) Mammals of Australia. Reed Books, Sydney.

Show us your spots! Quoll trapping in northern Queensland.

Recently, I went on a little data-collecting trip. The scenery was pretty cool and I was collecting parasites from some rather cute marsupials, so I thought it might be nice to share it with you.

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One of our rockier sites – a creek running through a gorge.

The field sites were on the Atherton Tableland, northern Queensland. Sites were in hilly, rocky areas, because we were trapping northern quolls (Dasyurus hallucatus), and they live in hilly, rocky habitats. Northern quolls are classified as ‘endangered’ by the federal government, which was one reason why this fieldwork was done – a colleague was collecting samples for population genetics analysis. Live mammal trapping involves getting up before sunrise to check traps nice and early (so the animals don’t get caught in the sun!), even though all our traps were covered with a thick layer of vegetation for protection. Walking around in the dawn light for the purposes of handling little marsupials is definitely one of those “I love my job” moments.

being at work at sunrise is not all bad.

Being at work at sunrise is not all bad.

It turns out that northern quolls are pretty easy to catch. Using collapsible cage traps baited with chicken frames from the butcher, we caught ourselves many quolls. The traps were treadle-operated, meaning that there was a little flap on the floor attached to the door of the trap by a metal rod. As an animal steps on the flap on its way in to eat the bait, it dislodges the rod and the door swings down, trapping the animal.

Northern quoll, Dasyurus hallucatus, in a bag.

Northern quoll, Dasyurus hallucatus, in a bag.

Once caught, the quolls get transferred to a handling bag where they had their measurements taken, and were examined for ectoparasites. Generally, they do not get checked for parasites, but because I was there, I collected any ectoparasites I found on each animal.

Me, collecting parasites from a quoll.

Me, collecting parasites from a quoll.

Paydirt! Ticks on the back of a quoll's ear.

Paydirt! Ticks on the back of a quoll’s ear.

After I’d finished picking at their ears and combing their fur (for fleas!), they got their photo taken – in a kitchen garbage bin, no less. It was the best thing to show up their spots, and they couldn’t jump out of it. Usually. We did have a couple of escape attempts. The purpose of the photography was as an identification method for upcoming remote camera trapping, as quolls have individual spot patterns. Then, they were done, and released at the site of capture. We caught several quolls again and again. Seems they didn’t mind the indignity of a night in a trap as long as they could have a chicken dinner!

Quoll showing us its good side.

Quoll showing us its good side.

Getting released - going...

Getting released – going…

Gone!

Gone!

Back at the lab, I have a collection of ticks, mites, fleas and lice from the quolls that were captured. I sorted them into separate vials and am now going through the process of identifying them. Some are easier than others! Very little is known about the parasites of northern quolls, so my work will shed a bit more light on the ecology of parasites on an increasingly rare marsupial.

It's like Christmas came early in the parasite lab!

Christmas came early in the parasite lab!

Monday Awesome: Quoll spotted in Victoria

Oh, man that was a bad pun in the title. For those not familiar, quolls have spots.

Dasyurus maculatus (image from Wikipedia)

The reason why a quoll-sighting in Victoria is exciting is because they are critically endangered in that region. Dasyurus maculatus, the spotted-tail or tiger quoll, is a largish marsupial found in Tasmania, parts of western Victoria and also has a coastal distribution from eastern Victoria into parts of coastal Queensland. However, none had been seen in the western part of Victoria for nearly 10 years, and there was concern that they’d become locally extinct. Today, via the ABC News website, we have word that a quoll was sighted and a scat taken that confirmed it came from a quoll. Yay! Hopefully that means that their numbers are increasing as a result of conservation efforts in the area.

The Easter Bilby!

Easter bilbies, with hopping mouse interloper! (still from Fairfax news video)

Here is a video of some lovely fluffy-looking bilbies from Sydney WildLife (I think it’s at Darling Harbour?). They’re raising awareness of the endangered bilby over Easter, because bunnies just aren’t cool in Australia. Personally, I like all the little hopping mice (Notomys sp.) trying to get in on the action. They are just too cute.

Bilbies  are getting screwed over by introduced species like foxes, cats and rabbits. No, the rabbits don’t eat them, but they do destroy bilby habitat and outcompete them for resources. The nocturnal lifestyle of bilbies in arid areas means that they are difficult for the public to go and see, so raising awareness of them via captive animals is a good thing.

Save the Bilby Fund has lots of information and pictures of these quasi-bandicoots.

http://media.canberratimes.com.au/news/national-news/easter-bilbies-come-out-to-play-3188519.html