Daryl,
I will join with Anthony
to say thank you very much for this very informative response to my question. It
makes bird identification seem positively easy in comparison.
It also begs the question
why this sort of information is not available on the Environment ACT website
for all to share.
Cheers
Alastair
From:
Bron King [
Sent: Wednesday, 21 February 2007
6:57 PM
To: Alastair Smith; 'Philip
Veerman'
Cc: Canberrabirds
Subject: RE: [canberrabirds] Warks
Road Antechinus
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
----- Original
Message -----
From:
To:
Sent: Monday,
February 19, 2007 8:03 AM
Subject:
[canberrabirds] Warks Road Antechinus
Yesterday I went up Warks Road for a
last chance at Cicadabird that has been reported up that way. No luck there but
I did see an antechinus and wonder whether anyone can help me to identify it. I
observed it about 0800 (about 1.5 hours after dawn) climbing down a dead and
blackened stump that was about 2 metres tall. It appeared to be a similar
colour (possibly a bit lighter) to a white-throated treecreeper that was
climbing up the stump.
My Menkhorst field guide
suggests that Dusky are completely terrestrial but are partly diurnal. Agile on
the other hand are mostly nocturnal so I am confused.
Any help gratefully
received.
Regards
Alastair
