At 10:22 12/02/2001 +1030, you wrote:
>Hi all,
> During the SAOA outing on Saturday someone posed the question
>" do all birds have some kind of tongue?" We all thought the answer had to
be yes, but some bird tongues are much more obvious than others, ie
honeyeaters with their well known brush tips and the parrot types with their
large fat tongues, but very little seems to ever get said about tongues in
other types of birds.
> We assumed that most birds use their tongue to assist in swallowing ( and
of course Swallows, no pun, and others use saliva in building their nests),
but what about say Cormorants and other birds which swallow ( gulp) down
quite large fish? And Pigeons which gulp down some very large fruits and
seeds? Wouldn't a tongue be more of a hindrance than a help in such cases?
>We couldn't imagine there being less than at least some tongue however
vestigial in all birds.
>Tony in Adelaide.
>
>
Hi Tony
You raise an interesting one here. There are just about as many
different types of tongues as there are feeding types among birds
but as far as I know and can find, all birds have tongues.
Some are protrusible - like the honeyeaters you mentioned and also
best seen in woodpeckers which have barbs on the tip of their tongue,
which are used to spear insect larvae, the muscles that operate this
tongue run right around the back of the skull;
Some are used to manipulate seeds and fruit in the bill, these are
often thick and muscular - seen in parrots and finches;
Birds of prey have rasping tongues, fish-eaters have backward pointing
papillae (barbs) to hold their slippery prey,
ducks and geese often have rows of hairs/bristles on the side of the
tongue - used for filtering out food from the water, in swans and
geese these may be larger and stiffer and used for tearing off grass;
In most birds the tongues are also used for swallowing, at their base
lie backwardly-pointing papillae which help to get the food down.
Birds like pelicans that swallow large items have small rudimentary
tongues. You are probably right that they would get in the way otherwise.
Saliva is another matter. Some birds like the Great Cormorant lack
salivary glands but most birds have salivary glands in a number of
regions of the mouth including the tongue. The cave swiftlets that
make birds-nest soup produce the sectretion from mandibular (lower jaw)
salivary glands.
[Most of this info comes from a book "Birds: their structure and function"
by Tony King and John McLelland that we use for teaching the vet students]
Cheers
Pete
Dr Peter Woodall email =
Division of Vet Pathology & Anatomy
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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