Warks Road Antechinus

To: "Overs, Anthony \(REPS\)" <>, "Alastair Smith" <>, "Philip Veerman" <>
Subject: Warks Road Antechinus
From: Bron King <>
Date: Thu, 22 Feb 2007 13:27:37 +1100
Mating among antechinuses is horrendously competitive, and only the strongest and fittest males 'get lucky'.  Contrary to popular folk-lore, it is not the sex act that kills them, it is the stress of the long and arduous mating season.  Every male is frantically engaged in searching for mates and brawling with other males.  They neglect their diets, and are super-charged with hormones.  All of these stresses cause their immune systems to collapse.  The proximate cause of death is generally bacterial infections and run-away increases in their endoparasite load.  For the lucky ones, one or more 5+ hour copulations provide a bit of compensation.

Male antechinuses in captivity, provided with regular good-quality food and spared the horrors of breeding, can live for 3 years.  But in the real world, their entire lives are lived out in exactly 11 months.

The antechinus you saw at Barren Grounds would be A. stuartii (Brown Antechinus).  I have also seen A.stuartii sun-basking at Jervis Bay, but as far as I know it is not common behaviour.  A. stuartii is a bigger and bolder critter than A. agilis.  I have seen many more of them in daylight than any other species.  But I have never seen a basking female with pouch-young .  Well spotted!

Daryl King

 At 11:31 AM 22/02/2007, Overs, Anthony \(REPS\) wrote:
That?s a most informative answer. Thank you for sharing that with us.
A question. Does EVERY male get ?lucky?? Are there any males (you know, those awkward, shy types that can?t dance?) that would miss out on mating and survive a second (or even third) year?
Also an observation. At Barren Grounds I would sometimes see an antechinus out during the day. Once I saw from the visitor?s centre window a female with little pink peanut-like babies attached to her belly lying in the garden bed catching a few rays.
-----Original Message-----
From: Bron King
Sent: Wednesday, 21 February 2007 6:57 PM
To: Alastair Smith; 'Philip Veerman'
Cc: Canberrabirds
Subject: RE: [canberrabirds] Warks Road Antechinus

A. agilis and A. swainsonii (Dusky) are both common in the Brindabellas.  They are both possibly more common at Warks Road than anywhere else in the ACT.  The junction of Warks Road and Blundells Creek Road is the type locality for A.agilis, which was described in 1998.

A. flavipes (Yellow-footed) is a woodland specialist and has never been trapped in that part of the ACT (it used to be reasonably easy to find on Black Mountain a few decades ago, but no longer).

A. agilis is the most arboreal of all antechinuses.  It lives in tree-holes and hunts in trees and on the ground.  A.swainsonii adults are strictly terrestrial, nesting and hunting in areas of friable soil.  Young swainsonii (less than 6 months old) occasionally hunt on fallen trees and in lower branches of coppiced trees.
Both species breed in winter, with the young dispersing over summer to coincide with food abundance.  80+% of antechinuses on the ground at the moment would be current-year juveniles. 

Both species are occasionally seen in early morning or late afternoon daylight hours, especially juveniles (which no doubt accounts in part for the high mortality of dispersing juveniles).  Both species may be abroad around the clock during the winter breeding season.

>From the point of view of climbing behaviour your antechinus could be either a juvenile A. swainsonii or an A. agilis.  At this time of year, most juvenile A. agilis are about House Mouse size, so you can rule them out.  A juvenile A. swainsonii would be roughly the same size as an adult female A. agilis.  Bear in mind that the only adult antechinuses in the population in summer are females (the males all having died in August following mating), so the possible size range is less than you quote (head and body for female A.agilis is 75-95mm).  Brindabella antechinuses are smaller than coastal animals - closer to the median of 90mm in the case of A. agilis.  If, in the unlikely event it is an adult female A.swainsonii, it is unlikely to be larger than 116mm.

I think it is more likely to be A. agilis.  The 2-metre burnt stump you describe is a typical nest-site for agilis.  Even an adult would risk a short daylight excursion from its nest if it detected a small skink or other high-value prey in the vicinity.  Climbing down head-first, antechinuses flatten themselves against the trunk with their hind-feet turned backwards and widely spaced.  This gives the impression of a larger animal than they appear on the ground.

Although antechinuses are the most numerous of marsupials, they are so cryptic that very few people will ever see one.  To spot one at Warks Road, in daylight, is a privileged experience.

Daryl King

At 08:19 PM 19/02/2007, Alastair Smith wrote:

I omitted the fact that it appeared to be a similar size (as well as colour) to the White-browed Treecreeper (160-175mm) would indicate that it was a largish species of antechinus (my initial reaction was that is was another white-brow climbing down the stump). As such, this which would probably rule out Agile (80-116mm) and point to yellow-footed (90-160mm) or dusky (90-185mm). I presume both species a re found in the ACT but interesting I cannot find a list of mammal species for the ACT (nor birds/retiles for that matter) under the Environment ACT website.
Many thanks to all those who have replied on and offline ? we?ll nail this identification yet.

From: Philip Veerman [
Sent: Monday, 19 February 2007 6:16 PM
To: Alastair Smith
Subject: [canberrabirds] Warks Road Antechinus
I don't think that colour is enough of a guide. They are all pretty much brownish. The size and shape are the issues. Most of the people who identify these critters have them in hand whilst doing so. Although just looking at a reference book now, suggests that size range within species is much greater than between species. Although a lot of that is sexual dimorphism, so if you don't know what sex it is, it is pretty hard to know what size it should be. They are all mostly nocturnal but of course during the breeding season, these critters go beserck and can be seen occasionally during the daytime.
I once observed (and caught) a Pygmy Possum at Warks Road (about 22 years ago), I have a photo of myself holding it.
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