name - Haliaeetus leucocephalus
are a member of the Accipitridae family, which also includes
hawks, kites, and old-world vultures.
loosely divide eagles into four groups based on their physical
characteristics and behavior. The bald eagle is a sea or fish
are two subspecies of bald eagles. The "southern" bald eagle,
Haliaeetus leucocephalus leucocephalus, is found in the gulf
states from Texas and Baja California across to South Carolina
and Florida, south of 40 degrees north latitude. The "northern"
bald eagle, Haliaeetus leucocephalus alascanus, is found north
of 40 degrees north latitude across the entire continent. The
largest number of northern bald eagles are in the Northwest,
especially in Alaska. The "northern" bald eagle is slightly
larger than the "southern" bald eagle.
have shown that "northern" bald eagles fly into the southern
states and Mexico, and the "southern" bald eagles fly north
into Canada. Because of these finding, the subspecies of "northern"
and "southern" bald eagles has been discontinued in recent literature.
eagle body description
- The adults have a blackish-brown back and breast; a white
head, neck, and tail; and yellow feet and bill.
bald eagles are a mixture of brown and white; with a black bill
in young birds. The adult plumage develops when they're sexually
mature, at about 4 or 5 years of age.
bald eagle is the only eagle confined to North America, and
there are no other large black birds in North America with white
heads and tails.
- The female bald eagle is 35 to 37 inches, slightly larger
than the male. With a wingspan which varies from 79 to 90 inches.
male bald eagle has a body length from 30 to 34 inches. The
wingspan ranges from 72 to 85 inches.
eagles weigh from ten to fourteen pounds. Northern birds are
significantly larger than their southern relatives.
golden eagle is larger than the bald eagle in average height
and wingspan, but there isn't much difference in their average
expectancy - Wild bald eagles may live as long as thirty years,
but the average lifespan is probably about fifteen to twenty
sit at the top of the food chain, making them more vulnerable
to toxic chemicals in the environment, since each link in the
food chain tends to concentrate chemicals from the lower link.
Temperature - 102 degrees Fahrenheit (38.8 degrees Celsius)
to cold temperatures - A bald eagle's skin is protected by feathers
lined with down. The feet are cold resistance because they are
mostly tendon. The outside of the bill is mostly nonliving material,
with little blood supply.
- Once paired, bald eagles remain together until one dies, the
survivor will not hesitate to accept a new mate.
- Shrill, high pitched, and twittering are common descriptions
used for bald eagle vocalizations. Eagles do not have vocal
cords. Sound is produced in the syrinx, a bony chamber located
where the trachea divides to go to the lungs. Bald eagle calls
may be a way of reinforcing the bond between the male and female,
and to warn other eagles and predators that an area is defended.
- It weighs about half a pound (250 to 300 grams), and is only
5 or 6 percent of its total weight. The feathers weigh twice
that much. Eagle bones are light, because they are hollow. The
beak, talons, and feathers are made of keratin.
diagram of a bird skeleton Another diagram of a bird skeleton
wings and soaring - An eagles wings are long and broad, making
them effective for soaring. To help reduce turbulence as air
passes over the end of the wing, the tips of the feathers at
the end of the wings are tapered so that when the eagle fully
extends its wings, the tips are widely separated.
help them soar, eagles use thermals, which are rising currents
of warm air and updrafts generated by terrain, such as valley
edges or mountain slopes. Soaring is accomplished with very
little wing-flapping, enabling them to conserve energy. Long-distance
migration flights are accomplished by climbing high in a thermal,
then gliding downward to catch the next thermal, where the process
is repeated. Several eagles soaring in a thermal together is
described as a "kettle of eagles".
tail - is very important for flight and maneuvering. While the
bald eagle is soaring or gliding in flight, the tail feathers
are spread, in order to attain the largest surface area and
increase the effect of thermals and updrafts. The tail also
helps to brake the eagle when landing and assists in stabilization
during a controlled dive or swoop toward prey. The strength
of the feathers and the follicles holding the feathers is quite
impressive, while watching the tail move back and forth and
up and down during maneuvers.
eagles have 7,000 feathers. Eagle feathers are lightweight yet
extremely strong, hollow yet highly flexible. They protect the
bird from the cold as well as the heat of the sun, by trapping
layers of air. To maintain its body temperature an eagle simply
changes the position of its feathers. While an eagle suns itself
on a cold morning, it ruffles and rotates its feathers so that
the air pockets are either opened to the air or drawn together
to reduce the insulating effect. Feathers also provide waterproofing
and protection, and are crucial for flight.
structure makes pliability possible. Overlapping feathers can
form a dense covering, which the birds can open or close at
will. The bald eagle has several layers of feathers, each serving
a different function. Under the outer layer of feathers is an
inner layer of down or smaller feathers. The inter locking of
feathers is an astonishing design of nature.
feathers enable eagles to live in extremely cold environments.
Eagles do not have to migrate to warmer areas each year to fulfill
temperature requirements, they migrate to available food supplies.
A lone eagle feather is believed to convey great power. North
American Indians incorporated the eagle's primaries and tail
feathers into their ceremonies and legends.
system - Eagles have external nares opening on both sides of
the bill. A bald eagle never reaches speeds that would interfere
with normal breathing. The eagle's lungs and air sac system
is adequate for its size. Air moves in through the lungs and
on into the air sacs before moving back through the lungs and
out again. Air passes through the lungs twice with each breathing
cycle - twice that of mammals. More about the respiratory system
- The hook at the tip is used for tearing. Behind the hook,
the upper mandible, the edge sharp enough to slice tough skin,
over laps the lower, creating a scissors effect. A bald eagle's
beak is a strong weapon, but is also delicate enough to groom
a mate's feathers or feed a small portion of food to a newly
beak of a female eagle is deeper (distance from top to chin)
than the beak of a male.
beak and talons grow continuously, because they are made of
keratin, the same substance as our hair and fingernails. The
beak of a captive eagle is not warn down naturally, so must
be trimmed annually.
- Talons are important tools for hunting and defense. Eagles
kill their prey by penetrating its flesh with their talons.
|| AREA NAME
(north of mile 30)
||Pilchuk to Ashlu (walk
to Pilchuk (rafting)
||I.R. Bluffs to Sunwolf
Slough to I.R.Bluffs
||Easter Seal to Judd Slough
to Easter Seal
||Training Dyke to Mamquam
||Railway to Art Gallery
||Garbage Dump/ Airport
||Old Main Channel
TOTALS FOR PREVIOUS YEARS
| 1986 / 537
|1991 / 875
||1993 / 1574
||1995 / 2597
||1997 / 1319
||1999 / 1847