January 2018
Pacific Northwest
Bald Eagles are common birds in the Salish Sea area, and there are 89 active nests in my county at last report, but up until last summer I’d never seen one occupied by a family. In my 30 years here I’ve checked out three big nests I’ve come across in my walks hoping to see some activity, and never have. The biggest problem in observing active eagle nests is that they prefer to locate close to shore: 97% of the nests (WDFW, Stinson, 2001) in Washington State are within half a mile of water (ocean, river or lake). That’s waterfront property, owned, guarded and intermittently occupied by the wealthy — which I’m not!
How did I find this one? Believe it or not, it was the Book of Face: a local friend posted a photo a nestling last June, and I asked her privately if she’d mind telling me where it was. She checked with the property owner who said it was ok, and it turns out the nest is actually easily visible from a public road! Granted it’s a lesser-traveled road in my semi-rural county, but I’ve driven by there countless times over the years and never noticed it. A perfect example of the mindlessness of routine and our human bias toward seeing what’s at ground level. Heh — I need to take my own advice to look up more often.
The nest is in a copse of firs surrounded by a field that is mowed in season by the farmer who owns the property. The road is bordered by an ad-hoc hedgerow, a linear thicket of native Snowberry and Nootka rose, so folks couldn’t trespass even if they wanted to (which I wouldn’t). Eagles become disturbed by intrusions to their nesting area, and interestingly it’s pedestrian activity that makes them most nervous (besides perceived attack from the air, like drones or helicopters). Research (pse.com/… ) near nests in residential areas found no effect on “juvenile feeding behavior, adult presence, and prey delivery rate”, except when people were walking around. Perhaps people are less predictable on foot, or less obvious to track. This nest has reportedly been here for years, and the farm and road longer, so these eagles have clearly accepted that kind of human presence. But to keep as low a profile as possible I observe them from my car out the window. If the car is stopped for more than a few minutes an eagle will turn to look at me but otherwise doesn’t stop what it’s doing.
In Washington, eagle nesting closes down when eaglets fledge in mid-July, so I was only able to see the very end of last season’s nest activity. More than half of our eagles in my county travel to mainland rivers like the Skagit and Nooksack in September to feast on spawned out salmon, returning in December sometime. Nevertheless, I very much wanted to see these eagles’ activity at the nest, so I made a point of driving that less direct route to see the eagle tree daily — or to be more accurate, Mr O did mostly since he motors up-island every morning for work (once again, Mr O does the heavy lifting in our marital unit lol).
Between his daily morning observations and my more occasional afternoon viewings, we noted the reappearance of eagles at the nest (presumably the same ones) at the very end of October. That was pretty exciting! And interesting — did they not fly over to the Skagit River, or did they return early? Since then there has been at least one eagle in or near the nest sometimes daily for a while, other times a week going by with nobody. Most often if an eagle is present it is perched either next to the nest or on a tall tree elsewhere in the field. A few times both eagles have been present.
Then on January 9 we saw what we’ve been hoping for since last July: NESTORATIONS! Both eagles were present, one in the nest, and as we watched, the other came swooping in to land there. The newly arrived eagle handed the other a branch and that one began poking it into the nest.
This is typical behavior for a pair of eagles planning to reuse a nest. Any reinforcement and refurbishment has to be complete before eggs are laid, which usually starts at the end of February around here. By the end of March most eagles are incubating, with most eaglets then hatching by late April. They are nestlings for three months, typically fledging in early to mid-July.
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We began watching on June 5, 2017. Last year there was just one eaglet in the nest which suggests food is not super abundant. Richer feeding grounds support more chicks. In Washington, "an average of 35% of active nests produced no young, 1 young fledged at 35% of nests, 2 young at 29% and 3 young at 1% of nests" (Stinson et al. 2001). We have a high density of eagles here, but this is probably why their numbers have leveled off after increasing over the past half century of Federal protection.
About a third of the time a parent eagle was perched nearby or in the nest. Otherwise the eaglet was alone, either lying down, or standing, mostly looking away (toward the south, where the ocean is about a mile away). Very occasionally it was preening or wingersizing. Once we saw it apparently cough up a pellet.
On June 27, the eaglet branched, and spent most of its time perched on a particular nearby branch.
Most of the drama we saw involved food, which was rare. Of course the eaglet was eating more than we saw, but with a few minutes observation per day, you miss a lot. This isn’t like a nestcam.
Once a parent flew in as we watched, with no food, and the eaglet whined steadily for the several minutes we were there.
On one occasion we saw a feeding. One parent was in the nest with the eaglet and the other flew in with food. In our area there’s a high probability it would be some kind of a bird. According to numerous studies in western Washington, eagles eat more birds (like ducks and gulls) than fish. A 1998 study (Stinson et al. 2001) of remains under 67 Puget Sound and San Juan Islands nests found that their food was 67% birds, 19% fish, 7% invertebrates, 6% mammals. And in the San Juans, feral European rabbits are a major prey source. A significant proportion of eagle diet here is also carrion, especially road kill. In contrast, eagles nesting inland, by rivers and lakes eat consideraly more fish than birds.
Then fur started flying. One parent — maybe larger? mom? — quickly tore fur off the animal, so I’m guessing it was most likely one of our abundant European rabbits.
Some time between July 11 and 12 the eaglet fledged. We never saw it at the nest again. A few days later one adult perched there by itself. Then the nest was empty until October.
My hope is these eagles will nest here again, and I can see the whole sequence of events this year. There’s something special about seeing this in real time in real life, even at a distance and intermittently.
I’ll be sure to tell you Dawn Chorusters about it if I do!
And as always please share your birdy observations from this past week!