|Subject:||Re: Endangered species|
|Date:||Tue, 30 Sep 2003 14:21:42 +1000|
Michael Norris wrote "A particular aspect of classifying a species as endangered
is whether its numbers are falling."
Not actually the case. Endangered species are those under threat of extinction. For very few threatened species do we have the data to say whether numbers are falling, stable or increasing although, to be fair, there is almost invariably a period where their population declined sometime in the past. For quite a few endangered species it would be safe to say that numbers are no longer falling. This, however, doesn't mean they are any less endangered. If the truth be known, the most dramatic current population decreases are probably among those species listed as "Vulnerable".
Freckled Duck are an interesting case. In NSW they are listed as "Vulnerable" rather than "Endangered". This is probably a pretty good description. Numbers are at around 30 000 - 40 000 birds (compared to 1 000 - 1 500 Regent Honeyeaters, for example) and the population fluctuates widely with the flood - drought cycle. A major potential threat to Freckled Duck is clearing of lignum during dry periods. This may be straight out bulldozing or grazing pressure by domestic and feral stock. Freckled Duck require old, thick lignum for breeding and appear to be pretty fussy in their requirements - hence the vulnerable status.
My two bobs worth.
Regent Honeyeater Recovery Coordinator
NSW National Parks & Wildlife Service
P.O. Box 2111
Dubbo NSW 2830
Ph: 02 6883 5335 or Freecall 1800 621 056
Fax: 02 6884 9382
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