Eagle’s lost nest

Thursday evening (May 16, 2024) a Bald Eagle’s huge nest came down when the top part of the tree blew off in high wind. The two chicks in the nest were killed in the fall to the ground far below as they were just sprouting feathers and still unable to fly. Their two parents survived because they could fly.

The nest was at Fraser’s Landing beside Cherry Bay on the west arm of Kootenay Lake. The nest had been a favourite of mine for a few years. Each year, I photographed the parents and chicks and watched the nest grow larger and larger. What the surviving parents do now is yet to be seen, but they may try to make another nest nearby.

A discussion of the problem faced by eagle parents follows shots from the last few days.

Less than two weeks before the wind, I had taken this shot of the mother on the nest. The two chicks are still too small to be seen above the brim of the nest, but what is evident is that the nest itself is gargantuan.

This was taken a day and a half after the top of the tree and the nest came down in the strong wind. The top of the tree and the debris of the nest is on the ground. The remaining lower part of the tree is standing on the right,

A day and a half after the wind, the two parents are in an adjacent tree. The male (right) has just flown in with a fish. They must now decided what to do. Photo by Cynthia Fraser.

Now, some reflections on the situation. Eagles like to find a tall largely bare tree (this one was dead) near the water. They started the nest maybe a half-dozen years ago. Each year they added to it, until it was big and heavy enough to bring down the tree in a strong wind. The question is: why was the nest allowed to become so big and heavy that it collapsed the tree and killed their chicks?

The simple answer seems to be parasites. Bald Eagles are at the top of their food chain and there are few other animals that catch them and eat them. But parasites are very small and are found on the tree and in their food. It seems that protecting themselves and their chicks from parasites prompts them to add a new fresh clean layer atop the nest each year. So, the nest gets bigger and bigger and this ultimately almost always causes it to fall in a strong wind. So, their tactic of adding sanitized layers makes sense. Unfortunately, they wait until the nest makes the tree fall rather that quitting after, say four or five years, and at that time building a replacement nest.

To celebrate this tree, here are two pictures from the past.

Both parents and two small chicks in the nest from 2022.

One parent and two larger chicks in the nest from 2021.

This is not the only eagle nest I have watched come and go. But, I want to mention one other dead tree that was visited regularly by Turkey Vultures until it fell down. Alas, as far as I know, it hasn’t been replaced.

For some time, a tree near Red Fish Creek was used by Turkey Vultures to warm their wings in the sunlight. But, these birds did nothing to bring the tree down; it just fell when there was no wind.