[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: Origin of flight
Glen Ledingham writes:
Birds and small mammalian predators like cats and
foxes often pounce with high leaps rather than the
seemingly more efficient flat leaps, especially in
tall grass. Perhaps this gives them better vision of
the prey and its evasive action or less resitance from
the ground cover.
A vertical pounce reduces the chance of the prey detecting the predator (and
thus taking subsequent evasive action). The eyes of most terrestrial
creatures are designed to look about in a horizontal plane, rather that to
detect attacks from straight above. Vertical pounces take advantage of that
blind spot, plus I imagine that using gravity to accelerate the predator's
mass towards the prey (and then crushing them against the ground) is
probably more energy efficient than a horizontal leap (where forces are
generated by muscles alone).
Most vertical pouncers detect prey with their ears, and may not actually see
the prey at all before catching them. Arctic foxes and polar bears both use
an attack from above to snare creatures hidden beneath the snow (voles in
the former, seals in the latter). Cats and foxes hunting in long grass also
tend to locate prey via sound.
GIS / Archaeologist geo cities.com/dannsdinosaurs
Melbourne, Australia heretichides.soffiles.com