At 08:54 AM 6/19/97 +1000, you wrote:
>One wonders what the effects of large scale consumption of chicken meat
>is doing to the raptors, given the recent reports of diseases in
>Penguins living near Antarctic bases as a result of eating chicken
>scraps. I don't know what the situation is in America, but poultry feed
>in many countries is full of antibiotics and hormones and some of these
>could be getting into the raptor population, with (probably) unknown
>effects. Have any studies been made of these chicken-eating raptors?
>Paul Osborn
Paul,
Can you tell me what antibiotics and hormones are present in poutry meat?
In my experience raptors in general are a tough groups of birds. Many of
the scavenging raptors probably have considerable resistance to bacterial
infections in particular. A rotting carcass is not exactly prime beef!
Another example is the group's resistance to biological toxins such as
botulinum toxin (the cause of many tens of thousands of deaths in waterfowl
around the world each year). The turkey vulture (Cathartes aura) is the
only known vertebrate that can eat affected carcasses with impunity.
Nevertheless, wild raptors do succumb to parasitic, fungal, bacterial and
viral infectious agents. Although, most of these diseases are usually
raptor-specific.
I wouldn't get too concerned about the serological evidence of Infectious
Bursal Disease (IBD) virus in Antarctic penguins. Disease has not been
demonstrated, only antibodies. Many wild birds have viruses which cause no
symptoms in the correct host species. Wild waterfowl have been demonstrated
as possible carriers of the IBD virus and these birds may even be the
primary source. IBD first appeared in poultry some 30 years ago. Before
then it "did not exist". Maybe we have found the original source....
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dr Shane Raidal BVSc PhD MACVSc (Avian Health)
Lecturer in Veterinary Pathology
Department of Veterinary Biology and Biomedical Science
Murdoch University phone: +61 8 9360 2418
Perth,WA, 6150 fax: +61 8 9310 4144
Australia
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