They must have seen some activity by Russ and Talia that felt like territorial encroachment. I am not sure if their vocalizing serves to "egg-each-other-on" but it sure seemed like a call to action. Ironically, from what I can see Marsha and Monty seem to be the ones who are encroaching. Until last year, this cottonwood used to be Russ and Talia's favorite perch at the southern end of their territory. Now, it clearly belongs to Monty and Marsha.
Portage Bay is a more distant part of Monty and Marsha's territory. From their normal Union Bay perches, I do not believe Monty and Marsha have a line of sight to see what is happening there. On Friday, I spotted this young Bald Eagle perched in a cottonwood tree on the south side of Portage Bay.
Monty and Marsha will often chase visiting Bald Eagles away, if they see them hunting in their territory, and if they are not out-numbered. I once did a post explaining the Bald Eagles must do math because they clearly know when the odds are in their favor.
People often ask if immature eagles, like this one, are the offspring of our local adult eagles. Honestly, without a unique identifying band or tag we cannot know for sure, but in general, I doubt it. My understanding is, that by their first Winter, the young are on their own. The implication is they disperse and roam freely, primarily searching for food, until they around 5 years of age. At which point, they develop a white head and tail, take a mate, begin defending a territory and prepare to raise young.
However, our three resident Union Bay pairs are not representative of all Bald Eagles. Many are migratory. This dynamic eBird map of weekly Bald Eagle sightings tells the story of migration far more eloquently than I can.
It shows large numbers of Bald Eagles migrating north during warm weather and then heading south for the Winter. In Western Washington, Western Canada, and Southern Alaska their movement seems to focus primarily on coastal areas, especially during the winter. Birds of the World (BOW) explains, "Adults and immatures from Alaska and the Pacific Northwest follow the salmon runs south down the coast; Adults arrive on Pacific Northwest wintering grounds Nov-Dec; immatures arrive later in Jan." (see citation below)
BOW goes on to say, "Northern birds return to the breeding grounds as soon as weather and food availability permit, generally Jan-Mar." The text also implies that mature birds migrate more directly when headed north, presumably this is because of competition for mating opportunities and territories. Apparently, the early bird gets the territory. Immature birds still tend to migrate north, but they take a bit more time since they are not yet competing for mates or territories. I wonder if their northern migration is related primarily to food availability or if they also feel a slowly-intensifying instinct to head north. I suspect that most of the non-resident Bald Eagles we see in Winter are migrants.
The young Bald Eagle in the prior photo was watching this second immature Bald Eagle as it circled over Portage Bay. The second Bald Eagle was also being watched by the Red-tailed Hawk circling above it. Soaring, circling, and rising up on thermals, takes very little energy. Once a bird has gained enough height it can simply glide north until it finds another thermal and repeat the process. I believe this is the key to Bald Eagle migration. Since thermals are caused by heat differentials their migration is most likely a daytime activity and probably most effective on bright sunny days.
I believe our resident Bald Eagles also use the thermals to circle up and hunt from a height particularly on sunny days. (This may be one reason why on cloudy days Bald Eagles are often seen hanging out at lower levels.) From what I have seen, Bald Eagles are often soaring carnivores who also have a very healthy taste for fish e.g. piscivores.
Buehler, D. A. (2020). Bald Eagle (Haliaeetus leucocephalus), version 1.0. In Birds of the World (A. F. Poole and F. B. Gill, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.baleag.01
1) Learn and leave established native flora undisturbed.2) Remove invasive species and then wait to see if native plants begin to grow without assistance. (If natives plants start on their own, then these plants or trees are likely the most appropriate flora for the habitat.)3) Scatter seeds from nearby native plants in a similar habitat.4) If you feel you must add a new plant then select a native plant while considering how the plant fits with the specific habitat and understanding the plant's logical place in the normal succession of native plants.
My intention in my weekly post is to include at least one photo each week and visually challenge us to know the difference between native and non-native lifeforms.
Also, Jane Lundin has created a small package, with a lot of critical information that looks quite handy, and light, for backpacking in the mountains in Springtime. It is titled, Mountain Wildflowers of Washington.)
My functional workaround is to set up my own email list and each week I manually send out a new post announcement. If you are experiencing the issue and would like to be added to my personal email list please send me an email requesting to be added. Thank you for your patience!