Mission: To promote the appreciation of wildlife and increase harmony between humanity and nature.

On Instagram and Twitter: @unionbaywatch

Wednesday, April 7, 2021

On Raptors

A Cooper's Hawk is a raptor, but...


The simplest definition may be, "Raptors are meat-eating birds who use their talons to catch live creatures, except for Vultures & Condors, and use their curved bills to tear their food apart." 

This definition requires the exception for carrion-eating birds since their food is not caught alive. The other raptors, who fit the definition quite well, are Eagles, Falcons, Hawks, Kites, Harriers, Ospreys, and Owls. Although, my Sibley guide does not explicitly label Owls as raptors. 

Excluded from the category are birds like Herons, Cormorants, Grebes, Kingfishers, and others. They also catch and eat meat but they generally swallow their prey whole and do not normally rely on their feet to catch their prey. 

Ravens and Crows are also excluded even though they do catch live prey. (Ravens are even intimidating enough to chase away raptors like Barred Owls and Red-tailed Hawks. Even so, they are raptor-like songbirds and not actually raptors.) I suspect they are excluded because they lack the extremely curved, meat-tearing bills, like raptors.

Speaking of these specialized bills, Does any other type of bird come to mind? If not, follow This Link to learn about a somewhat surprising avian relationship.

You may also want to visit the Urban Raptor Conservancy for another definition of raptors and information about their history in Seattle.

A Red-tailed Hawk in a Cottonwood tree in Autumn.

The hunting styles of raptors vary by species, individuals, and the specific opportunity. However, the most common approach, I have seen, is hunting from a perch. 

Red-tailed Hawks often perch on light poles next to freeways and Bald Eagles often hang out in Cottonwood trees next to water. Both will leap from their perch and drop quickly to initiate flight just above the land or the water. They use their low elevation to help hide their approach and hope to catch their prey by surprise.

Merlins are small Falcons who can combine hunting from a perch with a surprisingly high-speed, terrain-hugging approach. They will suddenly appear, coming in horizontally, at full speed. In a split-second, they must decide to attack or avert. They do not have time to debate their choices and their prey often lacks time to escape.

Peregrine Falcons are also known for their speed. They are the fastest creatures on earth. Like many other raptors, they will often initiate attacks while soaring, e.g. circling on thermals. After obtaining a target they will pull in their wings and initiate a vertical dive - called a stoop. 

Peregrines have unique physical gifts which enable them to handle the world-class pressure and speed that occurs during their diving attacks. They will use the same skills to hunt from highly elevated perches like cliff faces and, in our modern world, from skyscrapers.

Some raptors, also employ a less impressive, more parasitic, hunting technique. When a Bald Eagle spots a smaller bird with desirable food it will often give chase. Being weighed down, and considerably slower than normal, the smaller bird will usually give up the food in order to escape with its life. The Gull in this photo even regurgitated the large strip of salmon, to ensure its survival.

Barred Owls also hunt from perches although they generally work below a canopy of trees and often under the cover of darkness. They depend on shadows, silence, surprise (and excellent eyes) more than speed.

Another approach, used by Harriers and Short-eared Owls is to continuously circle above a field of short vegetation. Their method of surprise is to silently appear immediately overhead and abruptly drop on their prey. 

This week, I observed another hunting style, one which reminds me of a Cougar silently stalking Deer in a forest.

I was in the southern part of the Arboretum in the same area referred to in last week's post. Suddenly, an American Robin rose up from the ground and made a high-speed break to the southwest. It barely skimmed above the Sword Ferns, Salal, and Indian Plums. A moment later, another left the same area with the same urgency and trajectory. Almost immediately, two more followed on parallel paths. 

Normally, when American Robins are flushed by humans, they will simply fly up to a nearby perch and calmly wait for the person to pass. Often, they may even return to the same location and resume feeding. These birds behaved quite differently. They flew as fast as possible and gained minimal elevation. They were wasting no time while avoiding a serious threat.

My immediate thought was a Barred Owl or a Cooper's Hawk. I saw nothing moving through the branches. Plus, since Barred Owls normally hunt at night, I began scanning the underbrush to the northeast for a Cooper's Hawk, although a Coyote would have been another logical possibility. I saw no movement and heard no sounds, which implied the approaching predator had experience and skill. 

A moment later, this Cooper's Hawk silently rose from the ground and perched on a low branch partially hidden among the Indian Plums.

It continued to search the ground, no doubt, hoping to catch a small creature by surprise. (The orange barring on its chest indicated it was a mature bird.)

It looked to the left and right while ignoring me and my daughter's dog Ginger, before flying a few feet to the west. 

On its new perch, it continued the search. In this area, I have seen ground-nesting Dark-eyed Juncos and Spotted Towhees, as well as Varied Thrush, turning leaves for food, and Northern Flickers on nearby trees - all in addition to the American Robins.

Any of the above would fit the bill as a meal for a hungry hawk

At a fork in the Cottonwood above the bird's head is an Eastern Gray Squirrel's nest. They may seem a bit large but a Cooper's Hawk however the small Hawks tend to fight above their weight class. Plus, the native Douglas Squirrels, which are smaller, also frequent this area.

A small shiver seemed to overtake the Cooper's Hawk. 

By the way, the dark "cap" on the bird's head is one way to distinguish it from a Sharp-shinned Hawk.

It looked over its shoulder most likely focused on a sound outside of my range...

...before continuing to search the ground below.

Click Here to read a post that provides examples of Cooper's Hawks walking, hopping, or crawling through vegetation in search of food. The only other raptor, I remember watching, with a similar method of hunting is a Sharp-shinned Hawk. Since they are basically a small convergent-evolutionary version of a Cooper's Hawk, it is not surprising that they utilize similar tactics.

The Cooper's Hawk orange iris is another sign of maturity. 

Juveniles have light-colored irises. Although, the vertical stripes and dark little teardrops on their chests are a much more obvious sign of their youth.

I am pleased to say the Cooper's Hawk continued to hunt unperturbed by our presence.

Sadly, for the Cooper's Hawk, but happily for all the local prey species, it failed to find food while we watched.

On its next stop to the south, the Cooper's Hawk rose up to a higher perch. Perhaps, it was looking for movement in the vegetation before zooming back down to resume its "hands-on" approach to hunting.

When we remove trees and bushes and expand lawns in our yards and parks we remove habitat, food sources, potential nest sites, and cover for many small creatures. Certainly. lawns have value for many human activities. However, allowing trees and bushes to grow, or even just letting the grass grow to maturity provides cover and seeds, that can significantly help small creatures and birds. Helping them will in turn enable the continued survival of small urban raptors. 

For me, during this last year, nature in the city has sustained my soul. Observing nature has helped me to maintain both my mental and physical health. More bushes and trees, along with less cleanly mowed grass in the city, may not save the planet. However, if the next generation grows up experiencing nature next door they will, at least, have a personal understanding of the choices they face. 

Have a great day on Union Bay...where nature lives in the city and Black Birders are welcome!

Larry


Going Native:

Each of us, who breathe the air and drink the local water, needs to watch and protect our local environment. Native plants and trees encourage the largest diversity of lifeforms because of their long intertwined history with our local environment and native creatures. I have been told that 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 to 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. (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. 

(By the way, my friend Tom Brown pointed out that the application named 'Wildflower Search' is extremely helpful. Click on the highlighted link to see for yourself.

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.)



What type of plant is this? Is it native to Union Bay? 









Scroll down for the answer.











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Coltsfoot: On the positive side it is a native plant that loves well-watered locations. On the other hand, it apparently spreads, even underground, and can completely take over.

This small Western Red Cedar was cut to provide more light. The Coltsfoot has seized the opportunity and clearly colonized the previously protected area.









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The Email Challenge:


Over the years I have had many readers tell me that Google is no longer sending them email announcements regarding my posts. Even more frustrating when they go to 're-sign up', hoping that will enable them to once again start receiving the announcements, they get a message which says 'Sorry, you are already signed up.' Google has not responded to my requests for help with this issue. 

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. Something like:

                Larry, I want to see more of nature. Please add me to your personal email list. 

Thank you for your patience and interest!

My email address is: LDHubbell@Comcast.Net


*******************


One more photo:

 

Saturday, March 27, 2021

Tunnel Vision II

What species of bird is this? If you are new to birding this may feel like a difficult question. Surprisingly, the choices are fairly limited. There are primarily two candidate species.

They are a Ruby-crowned Kinglet (RCKI) or a Hutton's Vireo (HUVI). We'll come back to this in a minute.

This week a friend and I ran into each other in the Arboretum. As we walked downhill, towards the Japanese Garden, we heard a bird song that I did not immediately recognize. (This happens most often in early Spring - when many months have passed since the last time I heard the male of some species doing his Spring song.) A moment later we saw this bird which resembled a Ruby-crowned Kinglet.

The sound had come from high over our heads, while the bird was low and in front of us. I did not immediately assume a connection. To my credit, as the bird moved about the understory, I began to get an odd feeling. It was not moving with the extremely energetic pace of a Kinglet. 

Kinglets flutter and dart from one feeding opportunity to the next.  

In fact, the bird we were watching did not appear to be intensely searching for food. The slower pace helped me to realize that it might be a Hutton's Vireo. I started looking closer. I even wondered if the bird was looking for nesting material although I did not see it collect anything.

Here is a frontal comparison of the two species. (Since facial recognition is a critical human skill set, I have often wondered if a face-first approach to distinguishing bird species might be useful.)

On the left is the Hutton's Vireo and on the right is a Ruby-crowned Kinglet. If you look close you can see a faint hint of the ruby color on top of the Kinglet's head (and also in the previous photo). These tiny marks of red indicate they are males.

Between the eyes the Vireo is much lighter in color, plus, it has a wider and lighter colored bill and its eyes are offset on the side of the head rather than pinched-in and closer to the bill like the Ruby-crowned Kinglet. 

I checked a number of Ruby-crowned Kinglet (RCKI) photos with this same angle and the positioning of the eyes is consistently tighter than the Hutton's. This gives the RCKI an intense, hyper-focused appearance that fits well with its behavior.

By the way, both of these species are considered foliage-gleaning insectivores. I suspect their specific feeding methods may relate to the positioning of their eyes. Hutton's seem more likely to spot insects to their right or left while the RCKIs seem to be more focused on finding food directly in front of them.

This thought might even be extended to humans. Perhaps the many things we overlook happen in part because our eyes are forward-focused. We even have a common phrase that describes the concept, i.e. Tunnel Vision.

When we look at these two species from the side there are a few other distinguishing characteristics that become obvious. Here is a HUVI.

Here is a RCKI. 

The most conspicuous field mark is the location of the dark wing bar. On the HUVI the dark bar is between its white wing bars, while on the RCKI a similar dark mark is relatively farther from the head i.e. below its larger white wing bar. Less obvious is the break in the HUVI's white eye-ring, which is only broken at the top of the eye, while in the RCKI there are breaks at both the top and the bottom. Technically, we could call them eye-arcs instead of eye-rings.

The two bird species are very different in terms of migration and range. In Washington State the Hutton's live to the west of the Cascades year-round, while the Ruby-crowned Kinglets winter in our area but breed in the mountains - especially on the east side of the Cascades. 

In the big picture, the RCKIs migrate north and south all across North America while the HUVIs are primarily West Coast birds that migrate very little, if at all. Click on the following links to see dynamic weekly sightings from eBird.




Returning to the bird in our initial photo we now notice the light-colored bill (not black like a RCKI) and the eye-ring, broken only on the top. The dark bar on the wing is not as obvious as it could be, but it certainly does not exist below the lower white wing bar like a RCKI. Since the Hutton's Vireo is the only Vireo in our area which has an eye-ring with a gap at the top, this must be a Hutton's.

I wonder if this particular bird is just reaching maturity. Its eye-ring seems narrower than the other Hutton's (pictured above) and its dark wing bar is a bit faint. While this could be individual variation I wonder if these markings become more defined as Hutton's Vireos mature.

Zooming in for a very close look we can see one more difference between these two species.

The upper bill of the Hutton's Vireo is hooked at the end...

...while the tiny, black bill of a Ruby-crowned Kinglet is not.

The question that really stumps me is, Why do these two species look so much alike? We could guess that their coloring makes great camouflage but there are many other well-camouflaged birds with different color schemes. Plus, having similar wing-bars and eye-rings implies to me that there must be some additional value to a very close resemblance. The only idea I can think of is the slower and slightly larger HUVI might gain a slightly faster reputation by looking like a RCKI. Still, I doubt many predators are going to avoid a feeding opportunity just because their prey looks fast. I guess this is just one of nature's mysteries that is waiting for a brighter mind than mine.

While discussing this with a friend, his insightful reply was, "Have you asked Dennis Paulson?" My response was, "Ah, That is a great idea!" Dennis is a renown, life-long ornithologist, the instructor for Seattle Audubon's Master Birder Class, and has an amazing worldwide knowledge of birds. 

Here is Dennis' thoughtful reply to this line of inquiry,

"Hi Larry,

If you look through the kinglets of the world and the vireos with wing bars of the world, I think you'd see that they all look somewhat similar, little olive-green to gray birds with wing bars (and there are similar birds in some other families-how about Empidonax? (i.e. Flycatchers)). So both groups have fixed on the color pattern over evolutionary time. And of course quite a few vireos have eye-rings or spectacles along with their wing bars, so that is a commonplace color pattern in this family. However, of the six kinglet species, five have black stripes of their head and a visibly colored crown except the Ruby-crowned, and that is interesting. So to me the kinglet is more likely to have evolved to resemble the vireo than the reverse.

On the other side of the coin, the vast majority of the kinglet's range is not inhabited by Hutton's Vireos, so I can't imagine the bird diverged from the other kinglets (the four Old World species aren't called kinglets) just to look like a Hutton's, as it is still moderately different from the other wing-barred vireos.

So my conclusion is that it is just a coincidence that they look so similar. Olive-green for camouflage and eye-rings to call attention to the eyes for social interactions, but as far as I know, no one has explained the evolution of wing bars.

But to cogitate a little further, there is a hypothesis that some passerine birds have evolved to look more similar to some other species, in others words a convergence of appearance by two unrelated species, when they are part of a multispecies feeding flock. I'm not sure if this posited anywhere outside of the neotropics, though. The idea here is that you're more likely to be inclined to flock with another bird that looks similar to you. This could be stretching it a little, as many, many species in these flocks are quite distinctive and look nothing like the others, so the hypotheses is not supported extremely well.

I think no one, brighter than either of us, can really speak with confidence on why they are so similar! It makes a good story locally, at least, definitely worth calling attention to.

Dennis

The rich and varied mysteries of nature surround us. Maybe the similarities of these two species are purely coincidental or maybe there is some unknown hidden subtlety waiting to be revealed via creative inspiration and meticulous research. 

By the way, the song that we heard was very similar to the first recording you can hear when you follow - This LinkThis HUVI song is fairly unique and unlike a RCKI. It may be your easiest way to locate a HUVI in the Arboretum. Singing males are a sign that Spring, nest building, and eventually fledglings may be in our future - a welcome thought indeed!

Have a great day on Union Bay...where nature lives in the city and Black Birders are welcome!

Larry

ps: Maybe the scientific method is primarily a methodology for overcoming our Tunnel Vision. I sure hope it works.


Update:

A reader just contacted me to say she just found a Robin, who died in her yard, and appeared to be suffering from salmonella which can be spread via bird feeders. Please read the following from the Cornell Wildlife Health Lab: Salmonella. Cornell suggests, during outbreaks, removing bird feeders is to the greater benefit of the birds.


Going Native:

Each of us, who breathe the air and drink the local water, needs to watch and protect our local environment. Native plants and trees encourage the largest diversity of lifeforms because of their long intertwined history with our local environment and native creatures. I have been told that 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 to 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. (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. 

(By the way, my friend Tom Brown pointed out that the application named 'Wildflower Search' is extremely helpful. Click on the highlighted link to see for yourself.

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.)









What type of plant is this? Is it native to Union Bay? 









Scroll down for the answer.











***************










Clematis: An invasive non-native vine that covers-over and shades-out native vegetation. I may not have the precise name for the seed heads shown - regardless the impact on native vegetation is obvious. This photo was taken on the southeast corner of Montlake Cut below Monty and Marsha's Bald Eagle nest. (By the way, good things are currently happening in the nest!) 






********************








The Email Challenge:


Over the years I have had many readers tell me that Google is no longer sending them email announcements regarding my posts. Even more frustrating when they go to 're-sign up', hoping that will enable them to once again start receiving the announcements, they get a message which says 'Sorry, you are already signed up.' Google has not responded to my requests for help with this issue. 

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. Something like:

                Larry, I want to see more of nature. Please add me to your personal email list. 

Thank you for your patience and interest!

My email address is: LDHubbell@Comcast.Net


*******************


A few more photos:

HUVI or RCKI?

HUVI

Monday, March 15, 2021

Family Matters

Saturday, this Spotted Towhee landed, glanced over its shoulder, and then flew.

A moment later, this second one landed in almost the same location. How do these two birds differ? The sun and the clouds did not have time to move much, the only change in my camera settings was a slight focusing adjustment and my angle relative to the birds was virtually unchanged. The subtle differences in their coloring are realistically portrayed - not a photographic artifact.

The brownish back, on the first Towhee, indicates she is a female. The dark black back of the second one signals he is a male.

Being aware of their gender differences gave me the impression that the female bird was not quite ready to share the male's affection. She did not turn and aggressively chase him away, but she stayed a step ahead. Visually attractive, but just out of reach. Maybe there is work to be done, like nest building for instance, before she feels the timing is right.

Among the birds we see in our yards, a Spotted Towhee can look a lot like an American Robin. The dark back and the burnt-orange coloring look similar. However, the Towhee is smaller, has a shorter bill and a white expanse on the underside. The white on a Robin is harder to notice since it is primarily under the tail.

American Robins are somewhat similar to Spotted Towhees when it comes to the gender variation in their coloring. The female in the foreground is distinctly less vibrant than the male in the background. In the previous photo, you can also see the somewhat subtle difference between a male's black head and the grey-brown coloring of this female's head.

We see a similar situation with Varied Thrush. I wonder if it is because brown backs and heads blend-in better when a bird is sitting on a nest.

Once again the strongly contrasting, black markings indicate this bird is a male.

Dark-eyed Juncos provide one more similar example in another bird species that is often on the ground in around our homes. The male's vibrant dark hood provides an obvious contrast...

...while the female's grayish-black hood tends to more gently fade into the colors on her back and sides.

There are many species of birds where the males are far more brilliant than the females. Locally, the difference between the male and female Wood Ducks comes to mind. However, in the examples you have seen today, it is the subtlety of the differences that require us to pay close attention if we want a observe and understand the family dynamics in play. 

For example in the next few months, when you see two birds belonging to one of these four species in flight, you will now be able to validate the assumption that you are seeing a female being chased by a male. Potentially, even more interesting, is when and if the tables are turned.

For these, and many other species, we know it is to the female's advantage to blend in, particularly when incubating eggs or brooding her young on a nest. However, there is a third case where camouflage is equally important. 

Juvenile birds tend to be less sophisticated and far less aware of danger. They need all the help they can get to avoid predators and to side-step conflict and confrontations with adult birds.

Watching juvenile birds as they follow their parents, beg for food and learn to survive on their own is incredibly entertaining. Sometimes, they may even remind us of our own youthful missteps. However, if you want to fully enjoy this natural entertainment, as it happens in your yard, being able to identify the following juvenile birds will help. (Technically, only three of these species are likely to have their young in the city.)

In any case, if you are up for the challenge try to correctly identify the species of the following four young birds. They each belong to one of the species mentioned above. 

A)

B)


C)


D)
The answers will follow the Going Native section below.

Have a great day on Union Bay...where nature lives in the city and Black Birders are welcome!

Larry



Going Native:

Each of us, who breathe the air and drink the local water, needs to watch and protect our local environment. Native plants and trees encourage the largest diversity of lifeforms because of their long intertwined history with our local environment and native creatures. I have been told that 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 to 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. (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. 

(By the way, my friend Tom Brown pointed out that the application named 'Wildflower Search' is extremely helpful. Click on the highlighted link to see for yourself.

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.)









What type of plant, with these little reddish buds, is this? Is it native to Union Bay? What will its flowers look like?












Scroll down for the answer.











***************











Salal: It may take another two or three months before the native Salal will fully display its elegant rows of tiny white blooms.







**************






Juvenile Answers:

A hint for your first answer.

A) Dark-eyed Junco - DEJU - Ground nesters, easily preyed on by house cats.

B) Spotted Towhee - SPTO - Often ground nesters, easily preyed on by house cats.

C) American Robin - AMRO - Tree nesters, a bit less easily preyed on by house cats however our urban American Crows love to raid their nests just before the young fledge.

D) Varied Thrush  - VATH  - Tree nesters, that nest out of range for most house cats and urban Crows. The VATH will be leaving us soon. They will head for the privacy of more elevated and forested areas to build their nests, lay their eggs and raise their young.





********************






The Email Challenge:


Over the years I have had many readers tell me that Google is no longer sending them email announcements regarding my posts. Even more frustrating when they go to 're-sign up', hoping that will enable them to once again start receiving the announcements, they get a message which says 'Sorry, you are already signed up.' Google has not responded to my requests for help with this issue. 
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. Something like:

                Larry, I want to see more of nature. Please add me to your personal email list. 

Thank you for your patience!

My email address is: LDHubbell@Comcast.Net









A few more photos:
Can you spot the Varied Thrush?

****************

(Look right in the middle of the photo)



A few more photos of American Robin family members:
Juvenile

Male

Female