Newfoundland Bald Eagle Monitoring by Satellite Telemetry
Use of satellite and GPS telemetry is enabling researchers to track the movements of large raptors such as bald eagles. Current technology allows us to fix a bald eagle’s location multiple times during a 24-hour period, identifying its home range; and track eagles over large areas, identifying seasonal distribution.
Newfoundland’s Bald Eagle
Range
Monitoring
Concerns
Important Questions
Since 2008, up to five eagles have been tracked at one time using satellite technology. Maps following the progress of Bethany, Dexter, Jesse and Rachel will be posted on this site at the beginning of every month. Click on a thumbnail to open a PDF map.
Top of the Food Chain
Catching and tagging a wild adult eagle is not without its challenges and excitement. Read more about the eagle capture and monitoring process in Top of the Food Chain (873 KB) from the Winter 2010 edition of Our Wildlife.
January 2013
Jesse
Emily
Katie
December 2012
Jesse
Emily
Katie
November 2012
Jesse
Emily
Katie
October 2012
Jesse
Emily
Katie
September 2012
Jesse
Emily
August 2012
Jesse
Emily
July 2012
Jesse
Emily
June 2012
Jesse
Emily
May 2012
Jesse
Emily
April 2012
Jesse
Emily
March 2012
Jesse
Emily
February 2012
Jesse
Emily
January 2012
Jesse
Emily
December 2011
Jesse
Emily
Emily is a rehabilitated eagle from Salmonier Nature Park. She came into Salmonier’s care after colliding with and shattering a six-foot, double-paned window at the St. John’s Arts and Culture Centre in November 2011. After about three weeks of recovery, she was fitted with a transmitter and released near Paddy’s Pond. This bird will provide information on the recovery success of rehabilitated wildlife and hopefully go on to breed this coming spring.
November 2011
Jesse
October 2011
Jesse
September 2011
Jesse
August 2011
Jesse
July 2011
Jesse
June 2011
Jesse
May 2011
Jesse
April 2011
Dexter
Jesse
Dexter’s remains were found scavenged and scattered in a bog near Springdale in March 2011. The cause of death is unknown.
March 2011
Dexter
Jesse
February 2011
Dexter
Jesse
January 2011
Dexter
Jesse
December 2010
Dexter
Jesse
November 2010
Dexter
Jesse
Rachel’s transmitter stopped moving at the beginning of October. Conservation Officers from the Department of Natural Resources in Clarenville investigated and found her remains. All that was left were some feathers and bones, so the cause of death is unknown, but Rachel was possibly taken by a predator.
October 2010
Bethany
Dexter
Jesse
Rachel
After two years of providing data, Bethany’s transmitter appears to have failed
September 2010
Bethany
Dexter
Jesse
Rachel
August 2010
Bethany
Dexter
Jesse
Rachel
July 2010
Bethany
Dexter
Jesse
Rachel
June 2010
Bethany
Dexter
Jesse
Rachel
May 2010
Bethany
Dexter
Jesse
Rachel
April 2010
Bethany
Dexter
Jesse
Rachel
March 2010
Bethany
Dexter
Jesse
Rachel
Newfoundland’s Bald Eagles
Newfoundland has one of the highest populations of bald eagles in northeastern North America, with an estimated population about 300 to 600 eagle pairs in the province. They are popular among tourists and are highlighted by tour operators and tourism promoters.
The bald eagle is a large, conspicuous raptor that occurs exclusively throughout most of North America. It is considered at risk in parts of Canada, and has only been removed from the endangered species list in the United States.
A mature bald eagle has a distinctive white head and tail, and a yellow beak and talons. Colors range from all dark plumage as juveniles, to various phases of mottling as immature (two- to four-year-old) birds. As is typical of a relatively long-lived species, eagles lay up to three eggs, but usually fledge one or two young per nest.
Populations are generally considered secure over most of their range; however, like any birds of prey, bald eagles will normally occur in relatively low densities except where food might be abundant.
Eagles are both predators and scavengers, and are territorial during the nesting season. They take five years to mature and are considered to be a relatively long-lived species.
Range
Bald eagles occur throughout most of Newfoundland and Labrador. On the Island, they are primarily found along coastal areas during the nesting season, but may also appear along the coast and inland for the rest of the year. They do not appear to migrate off Newfoundland during the winter, but seem to move around seeking ice-free coastal areas to find food. They have also been known to hunt and scavenge inland.
One of the larger concentrations of bald eagles in Newfoundland occurs in Placentia Bay. In Labrador, they are almost exclusively found inland near large water bodies during the nesting season. In fall and winter, bald eagles from Labrador migrate south to the eastern part of the USA.
Monitoring
The Wildlife Division has been monitoring bald eagle populations in Placentia Bay and elsewhere in the Province since 1983. The program first began by soliciting public information on active bald eagle nest sites. Early on it became evident there was a relatively substantial population in Placentia Bay, which became the prime area for monitoring.
In the late 1980s a long-term monitoring area was established around the larger islands of Merasheen Island and Long Island, as well as part of the bay’s western coastline. Boat surveys of this area have been conducted at least 13 times since then. Most surveys were conducted in late June, when young bald eagles were 4-8 weeks of age; however, a number of early spring surveys were also conducted to determine territorial occupancy.
In addition to checking if nests are active or new nests have been established, these surveys have also gathered information about food habits and productivity rates. More than 100 eagle chicks have been banded, mostly in Placentia Bay, as part of an island-wide banding program that provides more information about dispersal.
Concerns
In the 1990s the impact of existing and future industrial developments on Placentia Bay eagle populations became a concern. Bald eagles are top-level predators and scavengers, and toxins and heavy metals that can harm these birds and their long-term survival can bio-accumulate (become highly concentrated) in their bodies.
Bald eagles may also ingest oil, which can prove lethal. This occurrence was well documented in 1989 during the Exxon Valdez spill in Alaska, when more than 150 bald eagles died as a result of the spill. Over time the population did recover, but with a small pool of thousands of eagles to support recovery.
Since bald eagles are excellent bio-monitors of environmental health, the Wildlife Division sponsored a student through Memorial University of Newfoundland to study toxin levels and heavy metals in eagles in Placentia and Bonavista Bays, with Bonavista Bay chosen as a control because of its very low level of industrial activity.
The results indicate heavy metal and toxin levels were relatively low and within acceptable parameters in both bays, although levels in Placentia Bay were higher. This information has established a good baseline to monitor for future changes in toxin and heavy metal levels in bald eagle populations in Placentia Bay.
Our annual surveys have also helped establish ‘hot spots’ for nesting activity within at least part of the Bay, and have developed a long-term monitoring data set from which to detect changes at a population level. In some years, close to 30 eagle pairs are found nesting in the study area, which is only a part of the bay.
Important Questions
A number of important questions still need to be addressed regarding bald eagles’ use of Placentia Bay, possible impacts of industrial development, and how such impacts can be mitigated. If, as we suspect, bald eagles do not migrate off the Island of Newfoundland, a limited pool of birds would have to support a recovering population if there was a significant mortality event. While we have some good information on breeding densities in part of Placentia Bay, we do not know the overall breeding picture.
We also suspect that areas of the south coast that are ice-free during the winter, including Placentia Bay, are important wintering sites for bald eagles from throughout Newfoundland. Also unknown is the home range bald eagles use during the breeding period. Such information is important when trying to assess the potential impact of industrial development, including accidental events such as oil spills.