Southern Ontario Bald Eagle Monitoring Project
The Southern Ontario Bald Eagle Monitoring Project, initiated in 1983, is a cooperative venture of the Ontario Ministry of Natural Resources, Canadian Wildlife Service, Bird Studies Canada, community organizations, landowners, and volunteers. Every year, landowners and volunteer nest monitors collect valuable data on Bald Eagle nesting chronology, activity and productivity, which allows biologists to monitor the health of the population.
From 1983 to 1999, Bald Eagle nests were accessed and eaglets were weighed, measured, and banded. Blood and feather collection was added to the protocol in 1990 in order to monitor levels of contaminants and heavy metals. Data collected from these field studies showed that by the mid-1990s, levels of contaminants had declined dramatically from historic highs. Coincident with the decline in contaminants, the number of active nests and the number of young produced at each nest increased, and the general health of the Great Lakes Bald Eagle population improved.
Every year the number of active territories and nests slowly increases. During the last five years, nesting productivity has stabilized at 1.4-1.5 fledglings per active nest, which is likely sufficient to maintain a stable population. Currently, most of the Bald Eagle nests in southern Ontario are located along the north shore of Lake Erie, though they are starting to return to the shores of Lake Ontario.
Future prospects for the recovery of Bald Eagles in southern Ontario are positive, but there are enduring concerns about the long-term viability of the population. Bald Eagles in southern Ontario appear to have shortened lifespans compared to other populations, possibly due to heavy metal poisoning. In the last few years, several Bald Eagles found dead in Ontario have had elevated levels of both mercury and lead in their bodies. Long-term exposure to such contaminants can limit eagles' reproductive capabilities, alter their behaviour, impair their foraging abilities, increase their susceptibility to disease, and even cause death. Determining whether heavy metal exposure is a long-term problem that is responsible for decreased longevity is one of the main issues that the Southern Ontario Bald Eagle Monitoring Project is now investigating.
How Can You Help?
BSC needs volunteer Citizen Scientists to participate in a number of conservation-related projects. To become a member of BSC and support wild bird conservation, contact us toll-free at 1-888-448-BIRD. As a member, you will receive updates on all of our regional, national, and international programs, and you will have opportunities to volunteer for various programs.
Bald Eagles are a Species at Risk in Ontario, so anyone who encounters an injured or dead Bald Eagle should contact Bird Studies Canada or their local MNR office immediately (prior to taking any bird into their possession) for instructions on how to proceed.
To report a sighting in your area, or for more information on the Southern Ontario Bald Eagle Monitoring Program (including how to become a volunteer or make a donation), please contact:
Biologist & Science Educator
Bird Studies Canada
PO Box 160
Port Rowan, ON
1-888-448-2473 Ext. 117