At 01:29 18/11/97 +1100, you wrote:
>Dear Peter,
>> Why does Harare have many native seed-eaters coming into the gardens,
>> while very few of the Australian finches do?
>
>What was the answer to your question?
>
>Glen
Glen,
Its good to see you [and your wit] back on the birding-aus lists!
I can pose many more questions than answers and I don't know
of a good answer to this one. I'll copy this to the wider community
and perhaps the cyber-fundis [=experts] can give some explanation.
I don't believe that marsupials
are biologically inferior to placentals, yet the fact is that both
Australian native mammals and birds have not done well in competition
with introduced species.
Why?
Is it to do with the isolation of Australia, but how would this work?
A suggestion that Australian animals are less adaptable is difficult to
believe because there have been great climatic changes, producing great
changes in habitat here, and in Africa.
Fire-induced changes - any more or less here than in Africa??
Is it to do with the far greater range of mammalian predators in Africa
(native cats, foxes, weasels, mongooses, etc) which has meant that the
African seed-eaters (and rodents, etc) have evolved with these predators
and therefore are better able to withstand the predation of suburban
cats? It is perhaps significant that there are very few
feral animals in Africa which sustain themselves sucessfully.
Is it to do with a longer human farming presence in Africa? The birds
there have had longer to adapt to a more permanent type of human
settlement than in Australia.
Any more ideas or suggestions would be welcome.
[The facts behind this are;
Garden Birds survey of Harare (Honeyguide 43:4-14, 1997) and Garden Birds of
Queensland [mainly Brisbane] (Sunbird 25:1-17, 1995)
Similar mean nos. per garden 40 for Qld, 29-35 for Harare,
Qld: four introduced in the top 50: House Sparrow 8th, Spotted Turtle-dove,
Common Starling, Common Myna. 6 native seedeaters in the top 50 species.
Harare: One introduced in the top 50, House Sparrow 29th,
15 native seedeaters in the top 50 species.
(ranking in terms of frequency of observation, seedeaters incude doves, parrots
and finches/waxbills}
Pete
Dr Peter Woodall email =
Division of Pathobiology
School of Veterinary Science Phone = +61 7 3365 2300
The University of Queensland Fax = +61 7 3365 1355
Brisbane, Qld, Australia 4072 WWW = http://www.uq.edu.au/~anpwooda
"hamba phezulu" (= "go higher" in isiZulu)
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