Le pygargue à tête blanche, une espèce en péril au Nouveau-
Brunswick?

L'auteur Rudy Stocek déclare : 
"La population du pygargue à tête blanche au 
Nouveau-
Brunswick est probablement plus étendue que vous le pensiez." 

L'habitat de reproduction est extrêmement important pour cet oiseau et c'est l'une des préoccupations principales lorsqu'il s'agit de protéger cette espèce. Autres enjeux connexes: prévenir les perturbations des oiseaux nicheurs et autres activités de foresterie. 

Une des raisons pour avoir mis ce rapace sur la liste des espèces en péril par le passé était la faible reproduction et les populations durant l'hiver. Cependant, 
M. Stocek affirme qu'il y a de grands espoirs pour l'avenir du pygargue à tête blanche au Nouveau-
Brunswick.

 

 

 

 

 

 

 

 

 

 

 

 

 

 


"This high profile predator is increasing in numbers and is expanding it’s 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."

 

 

The Bald Eagle
A species at risk in New Brunswick?


   Rudy Stocek
   Maritime Forest Ranger School
   December 2000

 

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?


(photo: National Wildlife Foundation)


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.


Eagle with Chick
(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.