Maritime
bird watcher stood mesmerized and perplexed by the many Bald Eagles
scavenging salmon in a British Columbia river. Is this the same species
of eagle considered endangered in New Brunswick? What makes them much
more "at risk" in that province?
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(photo: National Wildlife Foundation)
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The Bald Eagle population in New Brunswick is probably more diverse
than you might think. There are essentially two main age groups we can
recognize, juveniles and immature birds to four years old (generally
those that do not breed); and adults, five to approximately twenty years
old (which breed annually). The two segments of the seasonal populations
are the summer birds, that may breed and the wintering birds that may or
may not reside in the province. Freshwater and marine environments are
important summer and winter habitats.
Bald Eagles were not common in the earlier years. There are very few
nesting records back to the early 1900s. An eagle observation was a
notable event to most folks. The southern subspecies (breeding in the
southeastern United States) often summered in the Maritimes as young
birds. However, during the 1950s and 1960s few of those birds were seen
in New Brunswick. In the early 1970s I estimated that there were about
15 pairs of eagles nesting in the province, mostly in the southwestern
sector. The wintering birds, concentrating along the coastlines, were
also scarce in numbers.
(photo: National Wildlife Foundation)
The provincial Endangered Species Act of 1976 included not only the
Bald Eagle but also the Osprey. We had little information on the life
history of eagles, other than that there were few birds soaring the
skies of New Brunswick. That prompted me to continue my work on eagle
breeding biology and distribution. There was now one reason for putting
this raptor on the endangered list - low breeding and wintering
populations.
Yet there were other concerns for the protection of the Bald Eagle.
Breeding habitat is extremely important to this bird. It is particular
in choosing where it will nest and how many years it will continue to do
so. For example, one breeding area in the province was used for over 50
years. Because of their large size, these birds require a dominant or
co-dominant tree, often a white pine, as a nest site. I have noticed,
however, that more than 19 species of trees have been used for nesting
in New Brunswick. The nest is continually added to and can become very
heavy after a few years. The nest tree must be near a large body of
fresh or salt water and often within 100 metres of the shoreline,
because fish are often fed to the rapidly developing eaglets in the
nest. The tree must also allow the birds enough room for flying without
hindrance.
A variety of forestry-related activities such as harvesting and road
building can change eagle habitat to where the birds no longer nest in
an area. However, it is important to realize that raptors (eagles) are
now included in forest management plans. New sites are occasionally
recorded through the efforts of woodland managers. Essentially, a
distance of 100 to 400 metres around the nest site must be properly
managed to respond to the needs of a pair of eagles.
Disturbance of the nesting birds presents another problem. Any
harassment of the breeding birds or their habitat may force them to
abandon the nest site (and eggs or young). Summer recreation in the
breeding area, such as camping or canoeing, can increase the
disturbance. Nesting Bald Eagles should be left alone from February to
August.
Public education has been used as an opportunity to give the eagle a
high profile and to provide an understanding of the importance of this
ecologically unique and diverse raptor. Shooting of eagles in the
province has decreased over the years.
(photo: National Wildlife Foundation)
Currently there are about 70 breeding pairs of eagles in New Brunswick.
Wintering eagles have increased considerably since 1970 as demonstrated,
at least, by the annual Christmas Bird Counts. Over two-hundred birds
may be seen in Passamaquoddy Bay at some time during the winter. This
population increase is likely influenced by the concurrent increase in
salmon aquaculture units in the Bay. Operators have provided salmon
offal in one manner or another to the foraging eagles. The Bald Eagle is
now listed as "regionally endangered" on the provincial
endangered species list. An "endangered" species may be in
danger of extirpation throughout its range, but one classified as
"regionally endangered" treats that problem only within the
province. While Bald Eagles in New Brunswick are regionally endangered,
those in British Columbia are not at risk at all.
Will this bird continue to remain a species of concern? This high
profile predator is increasing in numbers and is expanding its
provincial breeding range in the last part of the 20th century. Just as
the Osprey has been taken off the endangered list, I believe that in
time the Bald Eagle will also become less of a species at risk.
