Ian said
>I have observed Galahs and Long-billed Corellas apparently picking up grit
from
>road surfaces on many occasions. Inspection of the road has not indicated
any
>potential food such as fallen grain. Analysis of the gizzard contents of
over 300
>Long-billed Corellas showed that, in almost all if not all cases, there
was grit
>present. Grit was mostly quartz pebbles 2-4 mm diameter. This suggests
that
>ingestion of grit is a normal, if not required, item for digestion of
grain in these
>birds.
My observations in sulphur crested cockatoos etc are similar. Many
graniverous birds have at least some pieces of grit in their ventriculus
and it helps mechanical digestion. Raptors on the other hand mostly rely
on chemical digestion in the proventriculus. Also, the normal diet of a
raptor should be high in calcium so the hobby may have been obtaining some
other nutritional, physical or physiological benefit.
Interesting
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Shane Raidal BVSc PhD MACVSc
Lecturer in Veterinary Pathology
Department of Veterinary Biology and Biomedical Sciences
Murdoch University phone: +61 8 9360 2418
Perth,WA, 6150 fax: +61 8 9310 4144
Australia
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