[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: T.Rex Feather Skepticism
Frank Bliss wrote:
>The cute tyrant looks like a good prey item for a hungry Upper Cretaceous
mammal to me. >Interesting that almost all domesticated barnyard birds are
fluffy and cute from the egg. I >wonder if artificial selection by man had
anything to do with that or just an adaptation for >surviving for cold
roosts. (Of course that theory goes out the window regarding turkeys!)
Of >course lot of other birds are born naked and "ugly" but do pen feather
up pretty quickly. Nothing >is more homely than a baby parrot in pin
feathers. I agree that we anthropoids do tend to prefer >baby creatures as
cute. Something about the mammalian survival benefit of cuteness ingrained
into >our collective wishful thinking.
It seems clear that we are simply hardwired to consider small, chubby,
seemingly helpless creatures as being cute. This reaction seems
particularily strong if they have large frontally directed eyes (half-grown
chicks of Tengmalm's Owl for example are *incredibly* cute).
Michael Habib wrote:
>Most domesticated barnyard birds are largely terrestrial, precocial forms
(and generally >galliform birds, specifically). They are 'fluffy' because
they must be capable of >thermoregulation soon after birth. The reason we
tend to domesticate such birds is probably >several-fold, including:
>1) They have large, light-fiber based pectoralis major muscles (good for
short, sprinting >flights), and we find this yummy.
>2) They live largely on the ground (which is related to point number 1),
which makes them easier >to contain and raise.
>These traits happen to be somewhat correlated with precociality (though
this is, in part, a >phylogenetic effect). Thus, these traits are
correlated with fluffiness. Other than the >phylogenetic constraints,
ground-living birds that are poor sustained fliers probably tend to
be >precocial, because the offspring are under pressure to leave the nest
early, and they presumably >utilize a food source available without flight
(since the adults are poor sustained fliers).
>The exceptions to much of the above are domesticated waterfowl; in that
they are strong sustained >fliers. However, they still feed on the surface
(water, instead of terrestrial surfaces), and >they still nest on the
ground in accessible regions (and they are considered to be sister taxa
to >galliforms, in many analyses), so it is not surprising that they, too
It is mostly a phylogenetic effect. All important domesticated birds are
either Galliforms or Anseriforms which are primitively precocial (as is
Paleognaths and indeed Neornithes). Also while galliforms and anseriforms
are presumably primitively ground-nesting many ducks nest in treeholes and
among the Galliformes the Cracidae are largely tree-nesting and tree-living
(and the chicks are incidentally rather better at scrambling around in the
trees than the adults).
T. Michael Casey wrote:
>Which brings up an interesting question: are any ground birds altricial?
Answer: Yes lots (e g larks, meadowlarks, buntings, harriers and even a few
ground-living woodpeckers and tits). However these are all secondarily
ground birds. Groups that are primitively ground-living all seem to be
precocial. Precociality once lost seems to be very difficult to re-evolve
(perhaps because it is more or less the opposite of neoteny).