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Re:Feathers again.

Date: Wed, 04 Sep 1996 10:52:59 +0200
Reply-To: fossils@redestb.es
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From: "Antoni Lacasa" <fossils@redestb.es>
To: mrowe@indiana.edu, cnedin@geology.adelaide.edu.au
Subject: Re:Feathers again.
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From: "Antoni Lacasa" <fossils@redestb.es>
Subject: Re:Feathers again.

LN Jeff wrote:

 Does anyone have data on how much better birds with waterproofed
feathers retain heat when they get wet than mammals?

I think that this structures are good in every case (mammals and birds).
Feathers and hair keep well the temperature in birds and mammals
respectively.In birds keep 39º-41,7º c. average body temperature and in
mammals about of 37º-38,5ºaverage. But the waterproofing is a little
different.In mammals intermittently linked to aquatic environments
(e.g.otters and others)requires waterproofing which makes it possible to
keep the downy  insulating layer dry, as well as trapped air remaining in
contact with te body.This is achieved by production and spreading grease
overs surface of the fur from sebaceous glands in the pilous follicles,
structures absent from the avian integument. In birds, the waterproofing
is on the closed network between its barbs and barbules in pinnate area
of body feathers and in its keratinous structure and perhaps a little the
oil of uropigial gland.
My opinion about it is that an ancestral group of dino-birds acquired
incipient feathers as an answer to their adaptation to continental
aquatics mediums in predatory incursions in the water in search food,
would tend to reduce body temperature A insulate and waterpoofing feather
covering,  would preserve the head body.

Toni fossils.