Turtle Bay Eagle Cam

Document Sample
Turtle Bay Eagle Cam Powered By Docstoc
					The State Route 44 Eagles
This pair of eagles first moved in and began to nest in the fall of 2004, but were not
successful hatching any eaglets during the spring of 2005. They returned the following
year, added to their nest and successfully hatched, raised and fledged one eaglet in 2006!
In 2007 they returned yet again fledging one eaglet.

Most Bald Eagles return from their wintering sites in February and begin nesting
behaviors in March or April. This pair of Bald Eagles has been returning to their nest
around December to begin their additions to the nest. Normally, they’re sitting on the nest
in January and incubating eggs in early February. They’re early this year, arriving the
first week of November, and have been sighted in and about the nest.

During the 2008 breeding season, construction began on the State Route 44 bridge
replacement project. Historically, Bald Eagles have needed quiet, undisturbed areas to
successfully breed. As human development has increased and encroached on their
territories, Bald Eagles are becoming more tolerant of the human environment. Despite
construction activities, they successfully fledged two eaglets in 2008!!

The Caltrans Eagle Cam
    Watch the eagles as they move around the nest. When they are maneuvering
      around the eggs and eaglets, they will ball up their feet so that they don’t damage
      them with their talons.
    Note that there is always one eagle in the nest while incubating the egg. They will
      take turns incubating and will even bring food back to one another.

Eagles of the World
There are 59 eagle species found through out the world. Eagle species are divided into 4
groups: True or Booted Eagles (Golden Eagle), Serpent or Snake Eagles (Bateleur Eagle),
Forest Eagles (Harpy Eagle), and the Fish Eagles (Bald Eagle). There are only 2 eagle
species found in the US: the Golden Eagle and the Bald Eagle.

The Bald Eagle is exclusive to North America. Bald Eagles range in size from 6 -16
pounds with wingspans ranging from 6-8 feet. Females are 1/3 larger than males. Bald
Eagles are smaller in the southern range and larger up north. Alaska has the largest Bald
Eagles and Florida the smallest. Bald Eagles can be found in every state except Hawaii.
Our National Symbol
The Second Continental Congress chose the Bald Eagle as our national symbol on June
20, 1782. It took 6 years to choose our national symbol. They wanted a bird that was only
found in North America and the final debate was narrowed down to two birds. John
Adams and Thomas Jefferson wanted the Bald eagle, while Benjamin Franklin wanted
the Wild turkey.

Life of a Bald Eagle
•       Bald Eagles mate for life, building a nest of twigs, mosses, grass and feathers near
        large bodies of water. They return to the same nest every year each year. First
        year nests are small but over many years become quite large. The largest Bald
        Eagle nest is over 30 years old and weighs over 2 tons! Because nests are
        vulnerable to damage due to wind, rain, etc, some Bald Eagles build smaller
        secondary nests nearby.
 •      The female lays one to three eggs and both the male and female incubate the
        eggs. The eggs are about the size of a goose egg and hatches between 32-35 days.
        The eaglets are altricial, hatch out with their eyes closed, are naked and totally
        dependant on their parents. The young require a lot of care and feeding by both
        parents, reaching full size in only twelve weeks!
•       Despite how quickly they reach full size, they do not get their white head and tail
        until they are four to five years old. Prior to that they are an all brown bird with
        white mottling on their bodies. During these immature years they are often
        mistaken as Golden Eagles.
•       The eaglets will hang around the nesting area for about three and half weeks and
        then head North. Studies have shown that eaglets fledged in Northern California
         travel to British Columbia and Alaska where salmon carrion is plentiful. (1992
        Hunt, Jackman)

Nesting Success
Not all nests are successful. They do not always produce eggs and eggs do not always
hatch. There are many factors that can affect nesting success, such as weather conditions
and availability and abundance of food sources.

Eaglet Competition
After the female lays the first egg, incubation begins. A few days later she lays the next
egg, and so forth. Therefore, the first egg will hatch days before the second. This is called
asynchronous hatching and is a survival tool for many birds. The first eaglet has the
advantage and can be significantly larger than its siblings. Eagles tend to lay multiple
eggs to ensure that at least one will survive to fledge. In years where food is plentiful, it is
no problem, but if food is scarce, the first, larger eaglet will have a better chance of
survival. In years when food is scarce, siblicide and aggression will occur. The larger
eaglet will become aggressive and often kill the other eaglet.

Approximately 4% of eagle nests have recorded having 3 eggs. Having 3 eaglets hatch
and survive is also very rare. Many times only 2 out of the 3 eggs will hatch. If all three
eggs do hatch, the youngest eaglet is at a great size disadvantage from the beginning of
its life and is usually outcompeted by siblings and starves.

Bald Eagles mainly eat fish. About 90% of their diet consists of live or dead fish. The rest
of their diet consists of any small animals they can catch along the shores including;
snakes, ground squirrels, goslings, ducks and coots.

Conservation Success
The Bald Eagle populations dropped in the lower 48 states from an estimated 100,000
breeding birds when it became our National symbol in 1782 to a low of 417 pairs in 1973
when the Endangered Species List was established. The main cause of decline was the
pesticide DDT used commonly in the 1940s and 50s. DDT was banned in 1972 and
captive breeding and release programs began. These programs, along with education,
worked to increase Bald Eagle populations. In 1995 their status improved from
endangered to threatened. With a current population of about 9,800 nesting pairs Bald
Eagles were removed from the Federal Endangered Species List on June 28, 2007!
Although removed from the Endangered Species List, Bald Eagles are still protected
under the Migratory Bird Treaty Act, California Endangered Species Act, The Bald and
Golden Eagle Protection Act, and designation by the State of California as a Fully
Protected species (Fish and Game Code 3511).

California’s Bald Eagles
California has a very healthy population of Bald Eagles. As of 2007, there are about 200
nesting pairs of Bald Eagles found throughout California. Of these nesting pairs, about
25% can be found in the North State. There are about 25 active Bald Eagle nests on Lake
Shasta, another 2 on Whiskeytown Lake, 8 nesting pairs on Lake Britton and 9 other
pairs within Shasta County. Most of the nests in Shasta County are along the Sacramento
River where food is easy to obtain and plentiful. During the winter, many Bald Eagles
from Canada migrate south to this area during the winter.

For questions about the video or the State Route 44 construction projects, please
Denise Yergenson
Caltrans District 2
Public Information Office

For any questions about the eagles please contact:
California Department of Fish & Game

Shared By: