Orange-bellied Parrot - population number

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Subject: Orange-bellied Parrot - population number
From: "Peter Menkhorst" <>
Date: Sun, 8 Feb 2009 15:30:08 +1100
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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