Alastair,
I should have asked if your size estimate was head-body or total
length. The figures you quoted in your original email exclude
tail-length, as do those in my reply. If you include tail-length,
the median size of an adult female A. agilis is 170mm.
Cheers,
Daryl King
At 06:57 PM 21/02/2007, Bron King wrote:
Alastair,
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:
Philip,
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.
Cheers
Alastair
From: Philip Veerman [
Sent: Monday, 19 February 2007 6:16 PM
To: Alastair Smith
Cc:
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.
Philip
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