Beauty Is Only Feather Deep
Was the bald eagle really the best choice of national symbol? A closer look at the habits and evolutionary lineage of this American icon casts doubt
Tinker, Tailor, Soldier, Sailor . . .
For the bald eagle, ospreys are a reliable source of nourishment;
for me, they're a reliable source of entertainment. Seeking such
enjoyment, I sometimes slip down to the Yellowstone River near my
home, one of many places where there is always an osprey. The last
time I tried this, I didn't have to wait long before one shot like
an arrow through the fall poplars. Skimming the water, black racing
stripe flashing across its cheek, the bird plunged head first into
the river, rose, banked elegantly and circled around to make another
dive, this time rising with a trout. Not a trivial accomplishment.
For birds, aquatic predation is a difficult skill to master. Of the
various species of large flesh-eating birds in North America, only
two are aquatic: the bald eagle and the osprey. Nature clearly gave
the latter better equipment. The osprey's barbed feet easily grab
fish; its oily feathers resist wetting; sealing nostrils prevent
water inhalation; translucent eyelids facilitate underwater vision;
and black eye stripes minimize water glare. More significant, the
osprey's talons turn backward, so that after it strikes a fish
broadside and lifts it out of the water, the bird can turn the catch
to face forward, making the load more aerodynamic. No other raptor
uses this trick. Bald eagles are far less adept fishers overall,
which is perhaps why they favor salmon runs where dead red fish,
floating or beached, provide an effortless meal.
So baldies can't match the osprey in an aquatic habitat. Put them on
land, and they'll fare even worse against the golden eagle. Not
surprisingly, Lewis ended his honeymoon with the bald eagle when he
began an affair with the "most beautiful of all eagles in
America," the golden, America's only true eagle, whose feathers
adorned the headdress of almost every Plains Indian chief. Baldies
may successfully steal from the much smaller osprey, but never from
the golden, a bird of equal size. Whether bringing down their own
prey or feeding on dead or wounded animals, golden eagles rule.
Lewis, for one, noted that on the golden eagle's approach "all
leave the carcass instantly on which they were feeding."
Interested in confirming Lewis's observations, I've hung out near
carcasses. It's good enough entertainment that I'm willing to wake
up before dawn and return to a scene repeatedly for several days
watching until the play is over. Lewis was right: The two eagles
enjoy strikingly different roles—the golden one feeds, the
bald one cowers.
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