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Re: The life of birds



Dann Pigdon wrote:
> Wouldn't the development of flight get you away from terrestrial
> predators (out of the frying pan), but within convenient snatching
> distance of pterosaurs (into the fire)?

Can't say for sure but the falcon-form birds show some adaptations that
pterosaurs (to my rather limited knowledge) do not.  Hitting an animal
as large or larger than yourself while in flight (as commonly down with
kestrels striking pigeons) does not seem likley to me simply due to the
way pterosaurs are constructed.

The falcon-form hunters have razor sharp talons which are supported by
amazingly strong feet and sturdy legs-to take the striking force/impact
of hitting an object at speed in flight.  The feet are the first part of
the predator to strike the prey and take nearly all of the impact.  The
pterosaur form with it's membraneous wings and patagium does not seem to
be adapted for fast and heavy strikes in flight   Pterosaurs didn't
attack with the efficiency of a falcom-form bird, certainly

Bats will use their wing and patagium membranes to scoop bugs up in
flight.  Bugs are not a terribly hard impact even at speed (just ask
your car window).  And bats will snatch bugs up directly while in
flight.  However bats have more maneuverablity than pterosaurs in this
as they have very short snouts to do the capture while in a chase
flight.  I doubt pterosaurs were adapted to snatch (flying) meals up
while in flight as the long snout common to pterosaurs would be an
impedement as the striking weapon at the front of the attack.  (One turn
of the head and your bow wave changes)

And it is highly likely that your mysterious proto-bird was probably the
size of a chicken-no small potatoes to take in flight at all.  It would
take a modern bird as large or larger than a Golden Eagle to take a
chicken-sized animal in flight, and even those would be reluctant to
strike a flying animal as large as that.  Far too much of the predator's
flight apparatus could be damaged by a flying animal of equal size.

Taking prey from the ground while in flight is another matter entirely. 
Birds do it regularily and bats will do it rarely (some bats make a
speciality of it however).  Taking prey while ON the ground (or tree
bound or whatever) is even rarer amongst bats and is quite common among
birds.

Birds seem more able to adapt hunting strategies than the other flying
vertebrates.  Pterosaurs would seem to have more to worry about from
airborn proto-birds than proto-birds would from airborn pterosaurs. 
Just imagine a flock of protobirds mobbing something Pteranodon-size.

-Betty Cunningham