The bald eagle
The majestic Bald Eagle never fails to arouse awe in every observer fortunate to spot it. In the 19th and 20th century, it variously was considered common to rare in North America, depending primarily on where you lived. They historically nested in 45 of the 48 contiguous United States, but have declined dramatically since then. The southern race that occurred in the southeastern states was easily found along that coast, but its northern counterpart was already scarce by the early 1900s. Then came the ‘70s and its populations, and those of many raptors, were devastated due to exposure to DDT and similar pesticides. Rachael Carsen wrote of this in her classic book – Silent Spring. In North Durham and the Kawarthas it has always been an uncommon migrant. In the past few years it seems to have become a bit more common and in 2017 it nested on Lake Scugog. There was also a nest in 2018 and it may have nested in 2019, but I haven’t been able to confirm that. Does anyone know? This is exciting news as it may never, at least in recorded historical times, have nested in Scugog Township! So let’s look at this great bird. It is a bird of prey and one of two species of eagles that occur here as migrants in the fall. The other is the Golden Eagle, which nests in extreme northern Ontario and beyond and migrates through here in small numbers in mid-October and November. The Bald Eagle builds a huge stick nest that may be used over many years. Each year the adults, which mate for life, add a few sticks and make a few repairs. Over time, this may create a burden on the host tree and it simply falls over or the top breaks off from the weight of the nest which can weigh up to a tonne. Hopefully, when his happens the baby eaglets aren’t in the nest. Often a White Pine is the preferred tree in our area because they are very tall and have massive trunks and supporting branches on which to build the nest. Two or three eggs are laid and are incubated for about 35 days. After 10-14 weeks, one or two of the young usually fledge, but rarely three. Then life gets tough as the mortality of first year birds is very high. After that however their chances of surviving to the age of 25 or 30 years of age are quite good. Food consists primarily of fish, small mammals and carrion, but I have seen them take ducks off the water in winter. If they can’t catch fresh fish, you are more likely to see them feasting on a washed up carcass on the shore of a lake! Identifying the adult bird is easy – they are huge and have black bodies and pure white heads and tails. They attain the adult plumage in the 4th or 5th year and then carried for the rest of the bird’s life. The young can be much more of a challenge as they are brown or mottled brown and white. Sometimes they can look very much like an immature Golden Eagle, so a careful study might be necessary for you to be sure what you saw. Its migration is interesting as most birds leave Ontario in the winter, although a few may stay if food is plentiful AND there are significant roost trees nearby. According the United States Fish and Wildlife (USFW) Northern States Bald Eagle Recovery Plan, there seems to be a definite link between large, stable, undisturbed roost trees and wintering numbers. The USFW speculates that, if these trees don’t exist in significant numbers, nesting likely will not occur and the large numbers of eagles that the west coast is famous for won’t materialize. So if you’re out anywhere in the Kawarthas or Scugog keep your eyes open. You might see this incredible bird and its young!
Geoff Carpentier is a published author, expedition guide and environmental consultant. Visit Geoff on-line at www.avocetnatureservices.com and on LinkedIn and Facebook.