This is good. Thanks for that. Some quick
comments:
I am curious at the quote "with males having longer wings
in proportion to their bodies, but being nearly half the weight of
females." That seems very odd to me.
Of course there is a lot of variation in
weight. I wouldn't think
that a male's weight
would normally be describable as "but
being nearly half" (i.e. less than half) of an average female's weight. In contrast I would have thought that males
would be typically be at least somewhat or slightly more than half the
weight of females. I think HANZAB supports me (although it is hard to
follow what their figures actually show). Jenny's 2008 CBN article gives data
that certainly supports my wording.
As for: "The birds
build a stick nest lined with leaves and may use different nests in successive
years, including those of other birds such as crows. " In the ACT that
should be ravens (not crows).
As for:
"There is some evidence of prey partitioning between little eagles and the
sympatric, larger wedge-tailed eagle Aquila audax, with the latter
tending to take larger prey and to eat more carrion...... However, rabbits are the most common
dietary item for both eagle species near Canberra ........ indicating potential for competition
for prey. " Yes but as rabbits are so
abundant, impact of that competition is minimal.
The nomination is based on a described decline in
status of the species. It provides some local survey data which is somewhat
supportive. Comparing the old and new Australian Atlas is not so clear cut, due
to different survey methods. I just looked at the latest COG ABR which doesn't
support the idea of a reduction in status. It even offers the idea of
misidentification, which I think is a bit of a furphy (they are very distinctive
birds) unless we can prove that there has been a consistent historical trend of
changes in rates of misidentification (and for what?).
Then there
is the issue of non
consideration of GBS results.
These are marginal for this species but GBS is a major part of COG's overall data set. It is at minimal
curious (but I reckon better
called dumb and
irresponsible) that this important
data set is not mentioned. The GBS data were
collected in a method that should have been uninfluenced by any bias in finding
or reporting information that would lead to any perception either way in changes
in status of this species. You should not just pretend that a large relevant
data set does not exist, because it does not support the case. It should be
mentioned and commented on why the data should be ignored. Because failure to do
so only highlights the deficiency. Any mention should be even to the extent of saying that GBS data does
not suggest a decline in numbers of the Little Eagle. The GBS
Report (Veerman
2006) Canberra Birds: A Report
on the first 21 years of the Garden Bird
Survey found. "It declined for the
first three years, then increased for ten years to a high in Year 13 then
declined again. It now appears to be stable." I have just checked and - needless to say (that even with plenty of empty white
space on the page), Birds of Canberra Gardens V2 does not add
anything new or useful to my original text that I wrote in 1999. There is a lot of GBS data on the Little Eagle but it does not hint at a
decline. I am not saying that GBS data
gives any basis to not be concerned. The only thing I can think of is to guess
or suggest that GBS data for this species is centred around likely the same
relatively few individuals being frequently observed in or over marginal habitat
and so possibly it may not give as full a picture of population trends of the
species as does other data. But even that is a weak excuse for ignoring it. Can
anyone else suggest a better excuse? Because it is beyond me. The GBS
Report also provides good evidence of the increase in Wedge-tailed
Eagles. This increase is something that is
mentioned and relevant to the document and thus the GBS data should have been included, as
that is very convincing data. The
omission of The GBS Report is also ironic if not ludicrous, given the
following quote from the report: "Community engagement is also important for
accessing community knowledge and resources (for example, wildlife expertise or
capacity to undertake volunteer activities). In the case of the little eagle,
knowledge of its conservation status and threats to its future well-being in the
ACT are, to a significant extent, a product of community knowledge and efforts."
