Harrison River Bald Eagles
Eagle Biology
The bald eagle, like its more formidable hunting relative the golden eagle,
is found throughout North America. But “Old Baldy” is more of an
opportunist and can be found scavenging carcasses in the grasslands and deserts as well as fishing along the rivers, lakes and coastlines. A few bald eagles seasonally make a living hunting coots, waterfowl or gulls.The big concentrations of eagles are wintering birds scavenging the dead salmon carcasses of the north west rivers.Breeding bald eagles disperse over most of the coast and into the interior lakes and waterways right across North America.
The Bald Eagle and its Relatives
The white head and tail of the adult bald eagle easily distinguishes it
from its own young or the golden eagle. The brown plumaged golden
eagle can best be distinguished from the brown immature bald eagles
by closely checking the feet. Golden eagles have feathers noticeably
covering the legs and toes, while the tarsus of the bald eagle (the 4 inches above the feet) are featherless and scaley yellow. If you see any yellow leg the bird is a bald eagle. The bald eagle is primarily a fish feeder but the adults can effectively hunt ducks. However, whenever possible they take the easy route and are scavengers. Other large birds sometimes confused with the eagles are the California condor, the turkey vulture, the osprey or large buteo hawks such as the red-tail.
Bald Eagle Nests 
Bald eagles nest under a great many circumstances. On remote islands
where there are no ground mammalian predators — particularly human or canid—they will nest on the ground or on rock pinnacles. Where big conifer
trees such as sitka spruce, Douglas fir or cedar are available, the eagles commonly nest in the upper canopy so that from the nest platform there is
a good view over the surrounding territory. These nests, in spite of the annual additions of branches and greenery, seldom get more than three to five feet deep, due to the high wind exposure and vegetative rotting. Along rivers and lakes the eagles commonly utilize deciduous trees. Along the west coast these are usually black cottonwood. In these the narrow forked structure often results in the nest, which is constantly beingadded to, being several meters deep. When the accumulation of this nest material exceeds the annual decay the nest eventually topples the tree or breaks the supporting branches.
An Eagle is Born
The bulky nest has an inner cup of soft warm moss in which the one to three eggs are laid. Eaglet at seven days of age. His thin layer of white down offers little protection and the parent has to brood the chick most of the time for the first ten days. Proud and inquisitive at five weeks of age. Now the thick warm grey down protects the chick against cooler weather when both parents are off hunting.
By eight weeks of age the chick’s body is nearly full size but the feathers have hardly started to grow. At nine weeks t he body contour feathers start to break through and within a week the head is feathered and offers the chick some real protection from rain.
Finally at 10 ½ weeks the eaglet has attained full size and the body wing feathers now have the large long bones on which to grow. At this stage the chick spends considerable time each day exercising its big wings in preparation of the first flight on the 12th week.For the first year of its life, the bald eagle has dark plumage. The feathers become mottled when the bird is two to three years old.
Four year old birds show an imperfectly patterned white tail and still have dark feathers on the head.
Finally, at five years, the adult displays the archetypal pure white head and tail that distinguishes the bald eagle from all other raptors.
Eagles in the Fraser River Area
The Harrison Bay, Chehalis Flats and Nicomen Slough areas of the Fraser Valley are the winter home to about 700 to 1,100 eagles. While there is a small resident population of Bald Eagle that nest throughout the Fraser River estuary, the birds observed here are from areas north of the Lower Mainland, including the mid to upper Pacific coastline,and many interior lakes and rivers.The actual number of eagles that you
see on a visit will vary. It will depend on the availability of salmon carcasses in the local streams, sloughs and rivers. The number of eagles visible will be greatly reduced if the temperature is low enough to cause the streams to freeze over, or if large amounts of rain cause the rivers to flow high and fast. In both of these cases the eagles will not be able to get to the salmon carcasses, and many eagles will move to other winter feeding areas.The best viewing period is from mid November through mid January. However, in some years, eagles have been present in large numbers well into late February. Peak numbers usually occur in late December and early January.
For complete festival details;
Fraser Valley Bald Eagle Festival - November 20 - 21, 2010
Website: www.fraservalleybaldeaglefestival.ca
E-Mail: info@fraservalleybaldeaglefestival.ca
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