Thanks Peter,
I sent my message before I had read your posting...
"I have been busy this morning liaising with Healesville Sanctuary about the
fire threat to the captive population of OBPs and Helmeted Honeyeaters which
I am pleased to say are now on their way to safe housing at Melbourne Zoo
until the fire threat recedes. Healesville's captive populations of Tas
Devils and Mountain Pygmy Possums are also being relocated."
That's great news!
Paul Dodd
Docklands, Victoria
-----Original Message-----
From:
On Behalf Of Peter Menkhorst
Sent: Sunday, 8 February 2009 3:30 PM
To:
Subject: Orange-bellied Parrot - population number
John Leonard asked about the number of OBPs surviving in the wild. Its
actually quite difficult to determine the population size of this species
because breeding takes place in the south-west Tasmanian wilderness area
where walking is the only means of access away from the Melaleuca airstrip,
and in winter the birds spread out along about 1000 km of mainland coast.
However, we do know that 80-100 birds return to the main breeding area at
Melaleuca each year, and some 60-80 young are produced there each year.
Small groups are known to breed elsewhere in sw Tas but the number of nests
found is very small [not surprising given the terrain and dense veg]. Most
young born at Melaleuca are colour-banded, yet a reasonable proportion of
juvenile birds sighted on the mainland each winter are not banded,
indicating that quite a number of young are produced away from Melaleuca
each year, but we cannot know how many.
To make matters more difficult, the efficacy of winter counts has declined
steadily over the last 10-15 years, ie the proportion of the known Melaleuca
population that we find on the mainland in winter is now only about 10-20%,
compared to about 50% during the early 1980s. So we have given up on using
the winter counts as an index of total population number.
So, a reasonable estimate of the total population size is a max of 120-150
adults, plus perhaps 100 juveniles, in March each year. By Nov each year
when the birds return to the breeding grounds the total population is down
to perhaps 150-180 birds.
More details can be found in the 2008 State of Australia's Birds report
issued by Birds Australia in December [and to be launched by Peter Garret in
Canberra in 3 weeks].
I have been busy this morning liaising with Healesville Sanctuary about the
fire threat to the captive population of OBPs and Helmeted Honeyeaters which
I am pleased to say are now on their way to safe housing at Melbourne Zoo
until the fire threat recedes. Healesville's captive populations of Tas
Devils and Mountain Pygmy Possums are also being relocated.
Peter Menkhorst
OBP and Helmeted Honeyeater recovery teams
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