|
July 2008
 The
bald eagle, once a victim of food-chain poisoning by the
pesticide DDT, is now is recovering remarkably from a
dive to near-extinction with a clear vision for a bright
future.
Once again bald eagles can be seen constructing enormous
nests 75-120 feet above the ground, normally near lakes
and rivers. From such towering command posts, they are
able to spot a fish in the water from almost a mile
away.
Their keen
eyesight comes not from magnification but from
resolution. Eagle eyes have many more cone cells than
human eyes, which help them see much finer detail. They
also have a feature most other animals don't – fovea:
two small pits in the eye filled with cone cells that
aid in focusing quickly and in accurately judging
distances.
Long live our keen-sighted symbol of strength and
freedom!
 Bald
eagle
Haliaeetus leucocephalus
3
feet tall; wingspan to 7½
feet
Habitat:
open areas and forests near rivers, lakes and seacoasts
© Tim Herd
photo by Leonard Lee Rue III |
