The feet of birds are as diverse as birds
themselves. Walking, running, perching, wading,
preening, scratching, and grasping are but
some of the
more obvious functions of bird feet. Some
adaptations are obvious, like webbed toes
for swimmers, some are subtle, like the toothed
comb on the middle toe of herons, used for
preening.
I can easily accept the advantage of woodpeckers
having two toes forward and two toes backwards
to facilitate clinging to a vertical surface
(tree trunk). Some believe that prairie birds,
like Horned Larks and Pipits, have extended
hind toenails to use as braces to keep them
from tipping backwards when the prairie winds
blow. I think the long toenails may be there
for an entirely different reason.
The next time you're birding, pay close attention
to the feet of birds observed and see how
many adaptations you can discover. Relate
these differences to the bird's food, behavior,
and habitat. To get you started, here are
a few of my observations. White-tailed Ptarmigan
sprout little appendages on the side of their
toes in the fall to serve as snowshoes during
the winter. Osprey have very sharp talons
and can catch a slippery fish that we would
have trouble holding on to. Many perching
birds have delicate feet but toes that close
automatically when the bird squats on a limb,
thus allowing the bird to sleep without falling
off the limb. Next time you have a bird in
the hand, gently bend the leg and watch the
toes curl up.
When are feet "hands"? When a chickadee
holds a sunflower seed while it opens it
up and eats the goodie. A hawk holds its
prey while eating. Parrots are probably the
most dexterous of birds with some being left-handed
and some right-handed.
Some birds use their feet for defense or
for courtship rituals. The spurs on the legs
of male pheasants and turkeys are well-known
tools to help a male achieve dominance. It
may surprise you that a kick from the thick
two-toed foot of an Ostrich is said to be
more powerful than that of a horse.
Some birds rarely have a need for feet and,
over time, their feet have become tiny and
weak. Whip-poor-wills, nighthawks, swallows,
swifts and hummingbirds have diminutive feet
and find it difficult or impossible to walk.
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