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Thursday, June 25, 2015

A Blue Bird Challenge

The blue birds in this week's post, spent their spring in the sagebrush, east of the Cascades.
Abundant water and food entices more than a hundred species of birds to visit Union Bay each year, however I have not seen any of these birds locally. 

There are three different types of "blue" birds, in this post. If you would like a challenge, you may:
  1. Look them up in a bird book,
  2. Find them online at All About Birds or BirdWeb 
If you are an experienced birder, you can test your recall by correctly naming each species.

Hints: 

  • Two of these species belong to the thrush family, just like our local robins. 
  • All of the birds were seen in either region 5 or possibly region 9 on BirdWeb.

Hunting insects from the air requires a large investment in energy.


A more cost effective approach is to hunt from a perch, just a few feet above the ground. (The difference in the bird's blue color between this photo and the prior is partially due to the light. In addition, the blue on the head and breast is lighter than the blue on the wings and the tail.)


Being closer to the prey shortens their airborne time and the effort required to secure food.


 This is particularly important in the spring when feeding young.

The male is not the only one involved in hunting.

The female also looks for food.

Her coloring allows her to blend in with the sagebrush, rather than than blending in with the sky, like the male.

It would be interesting to study whether the female hunts near the ground more often than the male, given the variation in their natural camouflage.

"The Birds of North America" implies that the variation in hunting styles is related to demand (e.g. young in the nest) and availability, it does not mention anything about variation by gender. In any case, hunting while hovering is apparently a last resort.

Our second type of blue bird resides in a similar habitat...

…but was spotted bringing fruit to its young, instead of insects.

This female bird also hunts from a perch...

…as does the male.

Here is a male of the same species; this photo shows some variation between individuals. Maybe this is due to age differences or partially the change in lighting between different habitats.

Here is our third type of blue bird. This species' blue coloring is darker in my Sibley guide and on BirdWeb, but the photos in All About Birds appear very similar to mine.


This bird's beak is a very distinctive clue. 

If you would like to validate your choices for the names of our three blue bird species, they are listed below at the very end of this post.

Thank you to Marcus Roening for leading this birding adventure!

Have a great day on Union Bay…where nature lives in the city!

Larry

A Challenge from Marcus:
What type of bird is this?

The Blue Bird Answers: 

The first species is the mountain bluebird, the second is the western bluebird and the final one is a lazuli bunting.


Friday, June 19, 2015

The Magical Owlets


Two young owlets ventured out of their nest in the Arboretum, last month. To the casual observer, barred owls, whether young or old, may seem very similar. They all have large eyes, predatory beaks, sharp talons and round heads. 


A closer look displays a number of differences between the adults and the young. The parents (I have started to think of them as Merlin and Morgan) have larger heads relative to their body size. Their tails and wings are also longer and the variation in their colors is much more crisp. As you can see in this photo, their adult coloring helps them blend in with their surroundings.


The owlet's youthful white down will soon be replaced with more functional feathers.


During the same time, the owlets' skill, experience and confidence will grow dramatically. 

Initially, the parents must provide all the food for their young. Learning to hunt successfully requires time to integrate a variety skills. The young must develop the patience to wait as potential prey approaches. They must determine which creatures are likely targets and which are too big or too fast. They must learn to fly silently between the trees and branches. Also they have to learn how to quickly and safely dispatch their prey. (In this photo, Morgan is offering the owlet the remains of a smaller bird.)

The young owls have to learn to triangulate the precise location of their prey.

Initially, their confidence and ability to fly is so minimal they spend their first few weeks out of the nest climbing about on branches. Older owls never get stuck with twigs in their face, but the young owlets need to keep a secure grasp on the tree, so they simply fight their way through the foliage. 

By the the third or fourth day out of the nest, this owlet climbed out of the cedars and into the long, leggy rhododendrons, which provided more spacious perches.

During the day, the parents are usually happy to sit and sleep and then awaken at dusk to hunt; although, during this critical parenting part of the year they are alert and aware of the young at all times.

Being well fed and full of curiosity, the young feel the need to move about, even during the daylight. Here the wings are being used for balance instead of lift.

So much to learn and so little time, the walk-about continues.

I was surprised to realize that weeks after leaving their eggs the owlets still often appear "egg-shaped".

Learning to balance is...

…just one of the many skills

… the young owlets must master.

Having sharp talons does help...

…compensate for their lack of balance.

Even with the wings slightly extended, their egg-shape is still apparent.

In the same snag where the owls nested, nuthatches and chestnut-backed chickadees also nested; maybe, the presence of the adult owls provided the smaller birds with protection from raccoons, cooper's hawks and other predators.

In any case, I believe stellar's jays were nesting somewhere nearby. As a friend pointed out, whenever jay's are present, but exceptionally quiet, you are probably near their nest.

Sadly, the peace and quiet did not last.

Just after the owlet negotiated its way up this rhododendron branch, it glided over to a coniferous tree, where it was quickly approached by a very loud Stellar's jay. Maybe the jay was attempting to protect its nest.

In any case, the noisy jay clearly intimidated the owlet. Not yet confident in its ability to fly, the owlet used its sharp talons to climb directly up side of the tree, while flapping its wings wildly. The jay kept up the constant banter, causing the young owlet to frantically climb higher and higher. Once the jay decided the owlet was no longer a danger, it moved on. The experience made me realize how a smaller more mature bird could easily scare young birds into making a fatal mistake.

Luckily, I was able to catch up with our young owlets this week. They both looked quite healthy and able-bodied. Their wings and tails are longer and they are now adept at flying. They are looking more and more like their parents. I suspect it would be rather unwise for a jay to try and harass the owlets now, particularly since the young birds seem very confident and full of the magic of life.

Have a great day on Union Bay…where nature does magic in the city!

Larry 

Saturday, June 13, 2015

Elvis Jr. Has Left The Nest

On Sunday, Elvis Jr. was clearly curious about the world outside the nest.

He even twisted all the vertebrates in his neck to look straight up, while his body faced the ground. Around the same time his father, Elvis, called loudly and chased a cooper's hawk away from the nest site. Constant awareness will be critical to Junior's survival. 

As part of his growing awareness, Junior used his tongue to explore the air. Pileated woodpeckers would be lost without their tongues or at least very hungry. They pull their primary food, carpenter ants and their larvae, out of the trees with their long barbed tongues.  (Click on the previous highlight to see Craig Johnson's excellent documentation concerning woodpecker tongues.) Watching the young explore with their tongues makes me wonder if pileated woodpeckers have a uniquely sophisticated sense of taste.

An obvious difference between Elvis and Junior. is the color of their irises. Elvis has yellow irises, while Junior's are grey-blue. A slightly more subtle difference can be seen in the brilliance of their red feathers, the young have a hint of orange in their red.

This year Elvis and Priscilla hatched out three young birds. Can you distinguish Junior from his sisters?

These are the girls.

This is Junior.

Maybe this is an easier comparison, with just Junior and one sister. Notice the red on Junior's forehead and along his chin, where the females have black feathers. Although due to shadows, Junior's red malar stripe can be hard to catch.

When they are very young, their colors are muted. This May 20th photo, shows Elvis preparing to feed one of the young birds. I suspect this nestling is less than a week old. It did not look or behave like its eyes were open. Because of the pink on top of the head and only gray on the forehead, I suspect this is one of the females. The amount of growth and change in just 17 days is phenominal.

By Tuesday morning, Junior appeared to be the last bird left nesting. His parents evidently decided that is was time for him to fly. In spite of his incessant begging, they did not deliver on his demands.

When Junior stopped his begging I looked up, startled by the silence. I got to see the last half of his first flight. He landed on this tree, which was leaning a few degrees off vertical. Junior immediately scrambled up the tree and then launched himself towards his mother, Priscilla.

This second tree was closer to vertical and covered with moss, but Junior had no problem getting a grip.

 After landing, Junior turned to look expectantly at Priscilla.


Priscilla appeared to debate whether Junior's first flight deserved to be rewarded.



  Finally, she moved closer…


 …and offered him food.

Priscilla has the same feather patterns as the young females, but her irises are a red-orange in color which helps make her easy to distinguish from the rest of the family.


Elvis, who had been standing guard on the opposite side of the nest, landed below them and watched the feeding.


 Elvis climbed the tree to check on Junior.



Junior seemed focused on Priscilla as she departed. Maybe Junior ignored Elvis because he did not offer any additional food.

The parents must find a delicate balance. On one hand they must make sure the young are hungry enough to be motivated to find their own food. On the other hand they also must feed them, to ensure the young enough energy to learn to find their food.

Last year in August, I found one of the 2014 female fledglings was still following Elvis and Priscilla, and apparently learning about new food sources. To see the post,


In 2014, Elvis and Priscilla raised two females. While in 2013 they raised two males. Click on the links below to see their photos in the nests:

2014 


The Birds of North America reports that the most common number of eggs in a pileated woodpecker nest is four. Hopefully, having three young this year means Elvis and Priscilla are growing stronger and will get closer to the norm in the future. In the meantime, all is quiet at the nest, which is why I suspect that Junior was the last to leave. If we keep our eyes open, we just might see Elvis, Priscilla and the kids somewhere on the south side of Union Bay. Feel free to leave a comment below if you spot them. Thank you!

Have a great day on Union Bay…where nature thrives in the city!

Larry

Osprey Update:
On Thursday, the osprey nesting platform was erected at the Union Bay Natural Area. The pole is in the southwest corner of the Natural Area. Now the excitement begins. When will the osprey take to the nest? Is there time for them to nest this year? Who will get to be the first person to see the osprey on the platform?

Special thanks to Jim Kaiser from Osprey Solutions LLC, to Dean Pearson and the UW Athletic Department, to Fred Hoyt and David Zuckerman at the UBNA and to the gentlemen from Prime Electric who helped attach the nesting platform and plant the pole in the ground!

More to follow!