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Thermalbiology (was Feduccia's errors)



In those birds where it has been measured, body temperature cannot be
maintained at air temperatures much below the thermoneutral zone when
the feathers have been removed.
    Roughtly, this means that at relatively high air tems, there is no
significant metabolic effort to maintain the hig, constant body temp. As
outside temp fall, the animal (all homeotherms) must increase energy
production to compensate for heat loss. Many birds can maintain normal
body temps to quit low air temps. In addition to metabolic compensation, the
insulation is increased by behavioral means (eg. fluffing the feathers).
     If the feathers are removed, and the air temp lowered, the metabolism
increases drmatically. But at relatively moderate air temps,the metabolism
peaks (close to the max as when in flight), and body temp falls.
      A naked homeotherm would have trouble  at even moderate temps
 regardless of where they were (tree, on the ground, etc).
      A 'dinosaur' with a body temp significantly would probably not maintain
 that temperature with out some ability (or mechanism) to insulate the surface
 of the body. Resting metabolism would be inadequate (as least as modelled in
 birds and mammals.
                                Cheers,
                                        alan


   Brush@uconnvm.uconn.edu
   92 High St., Mystic CT