This is the sixth year that the Ravens have nested in or around the Arboretum, before that it may have been a hundred years since they nested here. This is the first time, in the last six years, that their nest has been visible. Even though they have used this nest before, apparently, an obscuring branch has fallen or the foliage has grown out away from the nest.
Never before have we been able to see the young in the nest. If you look closely there is an upturned pink triangle to the right of the adult Raven. The adult's bill points directly at it. I believe it is the small bill of one of the nestlings. The photo was taken on April 3rd.
A moment later the Raven leaned over to feed the young one and the bill of a second hatchling appeared between the first nestling and the tree trunk.
Five days later, I happened to catch an adult approaching with food again. The bill of one of the young appears noticeably longer.
When the adult places the food in the young bird's mouth the size of the young one's bill seems enormous compared to what we saw just 5 days before. Their eggs are laid sequentially and they may hatch out on different days. So there could be size differences between the first to hatch and the last. AllAboutBirds lists their clutch size, i.e. the number of eggs per nesting attempt, as varying from 3 to 7 eggs.
By the 12th of May, their eyes were open, their heads were up and it was getting easier to see the young in the nest.
The next day I felt fairly certain that there were at least three young in the nest. AllAboutBirds also says that after hatching the young are in the nest for 28 to 50 days. I am guessing the availability of food is a critical factor in determining how fast they grow and how soon they leave the nest.
When they hatch out the young are defenseless. Luckily, their parents are aggressive defenders of the nest. They are also very attentive and return with food quite frequently. Given the rate of feeding appearances by the adults, it is surprising how often one can be found sitting in a nearby tree, apparently, on guard duty. I think the adults are primarily watching for Bald Eagles and Red-tailed Hawks, given their very excited "clucking" when they chase them away. This post from 2023 refers to one of those interactions.
Earlier this year, I watched one of the adult Ravens charge at two adult Bald Eagles that ventured near the nest. On average one Bald Eagle is about four times heavier than a Raven. Nonetheless, the single Raven succeeded in chasing both of the Eagles away. Fierceness, commitment and agility matter.
On the 16th of April, I was stunned to see the nest looked dramatically different. It appeared to have grown a wall of sticks above the previous edge of the nest. My first fear was the Bald Eagles had returned and raided the nest.
A few minutes later I was a bit relieved to see one young head appear above the nest. At about the same time an adult Raven returned with food (it is on the branch in the lower right of this photo).
Eventually, I went and examined the ground around the base of the nest tree. There were no signs of fallen sticks, no loose feathers and no evidence of anything falling from the nest site.
Later, I made out two young heads above the nest. I began to suspect that maybe the growing young Ravens had pushed the edge of the nest up and out, essentially, creating more space for themselves while making visible changes to the nest.
The other reassuring factor was the behavior of the adults. There were no apparent changes. They continued to come and go with food as if nothing happened. I am not sure how they would have behaved differently if they had lost a nestling. In any case, their continued consistent effort and hard work is reassuring.
I was away last week but when I returned the young in the nest were visibly larger and more mature-looking. Their awkward gangly looks were gone.
Even though I am sure the adults are still larger than the young ones, the most notable difference between them is the pink gape at the corner of their mouths. The adults are solid black on every exterior surface.
I am feeling relieved to once again see three young in the nest.
They are starting to spread their wings and flexing their newly developing muscles. If you look closely you can see that the base of the flight feathers are still visible. The coverts have not yet grown in. Once the coverts fill in they will create smooth and functional wings. Given their rate of growth from just three and half weeks ago I suspect they may begin branching out soon and potentially taking flight within the next week or two.
I read a study from long ago that said that a favorite food for Ravens is young rabbits. Perhaps our rabbit invasion from a few years ago is one of the reasons the Ravens returned. The availability of plentiful food may also explain why the young Ravens are growing so quickly.
This morning the three young Ravens were still in (or maybe I should say on) the nest. Given their size, the nest is looking rather small. Soon, they will have to move out onto nearby branches, which will provide more space while they flex their wings.
If you would like to watch the process the nest can be viewed from the bench immediately south of the "Rhododendron Glen" sign on Arboretum Drive. The nest is very high and a bit distant which is good. Given the nest's location, the foot traffic on Arboretum Drive does not bother the Ravens, but binoculars will be helpful if you want a good look.
Have a great day on Union Bay...where nature lives in the city and black birders are welcome!
Larry
Update:
My friend and birder extraordinaire, Dan Reiff, called to say that he has seen both Ravens and Ospreys in situations similar to what I described above. He evidently watched more closely than I did. In his cases he saw the adult birds build up the side of the nest that faced the direction from which the nest was being observed by humans (in this situation the build up was also in the direction of observation).
Dan felt certain that they did this to hide the nestlings from additional observation. I have no doubt the Ravens are smart enough to purposely build up the nest. However, in this case I did not see the activity take place so I cannot confirm or refute this possibility, however, I do not find it a particularly surprising scenario. Especially, given the skills and abilities of both Dan and the Ravens.
Going Native:
Each of us, who breathes the air, drinks water, and eats food should be helping to protect our environment. Local efforts are most effective and sustainable. Native plants and trees encourage the largest diversity of lifeforms because of their long intertwined history with our local environment and the local native creatures. Even the microbes in the soil are native to each local landscape.
I hope we can inspire ourselves, our neighbors, and local businesses to respect native flora and support native wildlife at every opportunity. I have learned that our most logical approach to native trees and plants (in order of priority) should be to:
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. (When native 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.
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Keystone native plants are an important new idea. Douglas Tallamy, in the book "Nature's Best Hope ", explains that caterpillars supply more energy to birds, particularly young birds in their nests, than any other plant eater. He also mentions that 14% of our native plants, i.e. Keystone Plants, provide food for 90% of our caterpillars. This unique subset of native plants and trees enables critical moths, butterflies, and caterpillars that in turn provide food for the great majority of birds, especially during the breeding season.
Note: Flowering plants and trees, i.e. those pollinated by bees, are also included as Keystone Plants.
This video explains the native keystone plants very nicely:
https://www.youtube.com/watch?v=O5cXccWx030
The Top Keystone Genera in our ecoregion i.e. Plants and trees you might want in your yard:
Additional content available here:
https://wos.org/wos-wp/wp-content/uploads/2022/10/Native-Plant-Resources-10-7-22.pdf
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In the area below, I normally display at least one photo with each post to challenge us to know our native lifeforms.
This small seedling will grow into which of the following Keystone tree species Oregon Oak, Big Leaf Maple, or Oregon Crabapple.
Here is a secondary hint, in case you are like me and previously had not noticed these interesting early leaves of this tree. In addition to the two first leaves this photo also shows what the third through sixth leaves can look like.Scroll down for the answer.
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Surprisingly, these are Big Leaf Maple (BLM) seedlings. They were photographed below this picturesque pair of mature Big Leaf Maples in the Arboretum just west of the Sorbus collection.
For comparison, this photo shows a bit more mature Big Leaf Maple leaves and a first-year Common Raven from May of 2023.
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The Email Challenge:
In response, I have set up my own email list. With each post, I will manually send out an announcement. If you would like to be added to my personal email list please send me an email requesting to be added. Something like:
Larry, Please add me to your personal email list.
My email address is:
LDHubbell@comcast.net
Thank you!
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The Comment Challenge:
Bottom Line:
If you write a long comment, please, copy it before hitting enter. Then, if the comment function fails to record your information, you can send the comment directly to me using email.
My email address is:
LDHubbell@comcast.net
Larry
