All About Ospreys At Union Bay

 Here is a recent post from the Union Bay Watch Blog published by Larry Hubbell, long-time local photographer and birder.

Paying Forward

What does this August 2020 photo tell us about our Union Bay Osprey?

In April (2020) the post 'Hope Returns' documented how our local pair of Osprey returned to their nest site above the Intramural Activities (IMA) Field Number 3. By the way, if you purchased food at the Safeway, or parked in the lot on the southside of the QFC, at or near University Village, during August, you probably heard this Osprey calling from its nest just south of 45th Street.

Osprey mate for life and each year they normally return to the same nest site e.g. they exhibit site fidelity. So, although I cannot scientifically prove that Hope and Stewart are the same pair who nested at the IMA field last year, it is a fairly logical assumption.

In May, a male, most likely Stewart, perched on the newly rebuilt nest. The carefully constructed curvature and the recently raised height of the nest were obvious indications of the pair's hard work to improve the nest for reuse in 2020. 

The question in my mind was whether they would successfully raise young this year. Last year, apparently for the first time, they raised just one offspring, Rama (Click Here to read Rama's story.). 

No matter how well-built the nest, if their eggs are not fertile, if they are continuously harassed by other birds, or if they cannot find a sufficient supply of food, their young may not survive. In 2018, the older pair, Chester and Lacey, that attempted to nest at the Union Bay Natural Area experienced similar issues.

Although individual survival is uncertain as a species, the Ospreys have done well. They are one of the most widely spread avian species on the planet.  

Within a few moments, after the previous photo, a second male Osprey attempted to invade the nest site. Stewart raised his wings in defense. Hope, can be seen returning, on the lower left. I cannot read her mind. Maybe she was coming to Stewart's aid or maybe she was returning to assert her ownership of the nest.

The intruder flew off to the east. 

Hope landed at the nest. Their mutual acceptance of each other increased my confidence that they were the same pair from 2019.

Moments later the intruder made a second pass at the nest. I did not notice the pair bringing any food to the nest so I suspect the intruder's motivation was related to mating. Taking over a newly rebuilt nest with a fertile female might be a pipe dream but I suspect the intruder's perspective was, "You never know unless you try."

Once again, Stewart defended the nest This time he raised straight up into the air. When an Osprey utilizes only the terminal half of their wings it usually indicates they are hovering. 

This same pattern of wingbeats is seen when they hover above the water - watching and waiting...

...for a fish to come within in reach of a head-first dive. (Click Here to read more about this particular diving bird.)

Once again, it was the intruder who was intimidated and decided to evacuate the area. 

During the pandemic, I was unable to watch the nest as closely as I would have liked. For one thing, the field was fenced off for much of the summer to discourage students from playing soccer, e.g. congregating and spreading the virus. 

However, by mid-August, the field was reopened to individual use. I finally caught a fairly decent photo of a first-year bird in the nest. The young bird was most likely about two months old at this point. The white trim or edging on its dark wing feathers is the most prominent indication of its youth. 

From a great distance, I thought I saw multiple young birds in the nest but I did not have conclusive proof.

Two days later, just before dawn, I finally captured a photo of all three young in the nest. Their existence (and residence in the nest) proves Hope and Stewart's reproductive success in 2020.

Less than ten minutes later, as the sun rose above the horizon, two of the young had already left the area, maybe off searching for food.

The third youngster finally decided to follow. It flew south towards Union Bay. Lucky for us, it decided to land on a relatively short power pole near the maintenance facility. This enabled a much clearer view of its pristine youthful feathers.

This 2016 photo of a more mature bird, shows how dramatically different an adult's feathers can be. The uniform white tips of its youthful feathers have either worn away or been totally replaced. The lighter brown wing feathers show how feathers fade from exposure to the wind, rain, and sun. Plus, the newer, darker, partially-grown feathers make it particularly obvious that this bird was molting.

Another indication of its youth is the orange coloring of the young bird's iris.

For comparison, here is a 2017 photo of Lacey, the mature female from the older (and currently unused) nest in the Union Bay Natural Area. She has the yellow iris of an adult. The brown sprinkling on her chest indicates she is a female. (Click Here for an uplifting part of her story.)

In the case of the young bird in the previous photo it has a very light sprinkling of brown on the chest. I am uncertain if that truly indicates it is a female or if it is juvenile coloration on a male bird that may disappear as it matures.

In either case, from the top of the power pole, the young Osprey flew to the northwest. It landed on a dead branch above the remnant of Ravenna Creek e.g. between the IMA field and the UW Driving Range. (Click Here to see my map which includes the area.)

The first photo in this post shows this same bird on the same branch. 

At first, I wondered if the young Osprey was inspecting the water below for fish. Watching a young bird as it makes one of its first attempts at hunting would be quite exciting.

Sadly, that did not appear to be the case. Apparently, it was experiencing some difficulty...

...with balancing on the skinny little branch.

Soon, its intent became obvious.

It spent quite some time picking bark off the branch. I suppose it was good practice since it is fairly similar to, although far less nourishing than, removing flesh from the bones of a fish. (Fish which are the primary food of Ospreys.)

Later in the morning, all three young returned to the nest. At this point in their development, I believe the parents were still feeding them and primarily doing so at the nest. 

On the last day of August, I found two of the young in the nest. They were calling loudly as an adult approached with food. I am assumed their other sibling was out hunting on its own.

The adult made a quick stop to drop off the food.

The nearly pure white chest indicated this was Stewart - their father. The young bird on the left grabbed the fish and used its body as a barrier to deprive its sibling of access to the food. The action looked somewhat similar to a human child grabbing a toy and crying, "Mine, mine, mine."

In fact, the young bird put an exclamation point on the thought. It picked up the fish and flew away. 

The whiskers on the front of the fish indicate it is a bottom feeder. It looks like a catfish to me. Since Osprey can dive up to three feet deep in the water I suspect this fish made its fatal mistake when it swam into shallows.

The young Osprey landed in a tree above the 'Ravenna Creek' Greenbelt.

As the young bird began eating the fish, the wind lifted a few white feathers from the area that I can best describe as its wing-pit. 

I do not know a formal name for these feathers. It appears to me that they improve aerodynamics by helping to cover and smooth out the area where the wing connects to the body.

The feathers are far less obvious when laying in their normal position.

Back at the nest, the sibling watched. No doubt there was some wishful thinking going on.

This view of the nest provides a very good comparison to the second photo in this post. It shows just how much the nest has disintegrated during the three months from May to August. The constant movement and landing by five different birds caused branches to slough off and fall. Although, since all the young could fly at this point, it was no longer a dangerous situation.

Soon after I turned back, the feeding bird stopped eating and began mantling its food.

Mantling is the process of spreading its wings and tail feathers in an apparent attempt to hide its treasure e.g. the fish. It took me a moment to realize what was happening. I saw a flash overhead and peered through the branches to see that the sibling had flown over hoping for a morsel or more.

As I tracked its progress, the hungry sibling returned to the nest.

Luckily, its mother, Hope, had been watching out for its well being.

Hope, returned to the nest with food.

She dropped off the food but did not linger. I suspect young birds, who are inexperienced with their deadly talons, beak, and large wings may be a bit dangerous in close quarters. Parents may prefer to keep a safe distance.

Hope, stopped and perched on a nearby light pole. It became obvious she was protecting the young and their food when a second adult female landed on the opposite side of the field. Hope lifted off and escorted the new adult female out of the area and away from her young.

Once again, I have not been able to keep a close eye on the Ospreys, this time due to the forest fires. Normally, at about this time of year, the adults head south for the winter. The young tend to stay behind, find food on their own, perhaps put on a few more ounces of weight, before heading south. Surprisingly, they make their first migration, as far south as Mexico, without any previous experience in migration or any physical guidance or presence of an adult. I certainly hope they find or found, alternative routes around the fires.

At this point, all we can do is wait for spring and watch to see if both adults return in 2021. In terms of this year's young we will have no way to know if they survive. However, we do know that their parents have given them a strong start and a good opportunity to succeed. Even as vastly different as we are from birds it is surprising how similar we are in our most important motivations and desires. I hope we do as well.

A)

B)

Which species of trees are these? Are they native to Union Bay?

Since you can't hold these branches in your hands and measure the length of the needles I will provide you with some additional information. 

1) Both trees are a type of spruce. 

2) Many of the needles in the first photo are over 2 inches longs. 

3) Many of the needles in the second photo are only 1/2 inch long. 

4) Both have cones that are often longer than four inches.

 

As you can tell from their names neither of these trees is native to Seattle. 

A) = Himalayan Spruce: Among spruce, this one has the largest cones and the longest needles. 

B) = Norway Spruce: In his book "Trees of Seattle" Arthur Lee Jacobson says that the Norway Spruce is the most abundant spruce in our city.