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

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Saturday, May 27, 2017

Cottonwood Seeds

This week's post focuses on three species of waterfowl which give birth to precocial young. Immediately after hatching, these young birds open their eyes, leap to their feet, fluff up their feathers and begin looking for food.

An Anna's hummingbird illustrates the opposite. Altricial young are featherless and cannot see, walk or find food. Without a parent their chances of surviving would be zero. 

From one species to the next, the variance from altricial to precocial can be seen as falling on a scale with multiple increments. You can read more about the different initial abilities of avian species in this post from Stanford.

Your challenge this week is to try and determine the correct species for each of the following three types of precocial waterfowl. These two fluffy little creatures belong to our first species.

This pair of young birds represent our second species...

...while these sober little souls are members of species number three. 

All three species were photographed near Foster Island this week. Regardless of their differences, they all appeared to be eating the same type of food - cottonwood seeds. 

As those of you with allergies can attest, cottonwood seeds are abundant this time of year. Nature's timing is impeccable. These seeds float down from the trees at precisely the same time as our local waters fill up with hungry young birds in need of their first meal.

The consumption of these seeds shows that the value of cottonwood trees extends beyond providing nest sites and beaver food.

Our first species is clearly different from the other two. However, I find that there is not much resemblance between these young birds and their parents. One exception is that their tiny bills look similar to the adult's.

At this time of year, cottonwood seeds are so plentiful that these young birds, from our third species, filled up quickly and had time to sit in the sun. I thought the bird in the middle looked like it was trying to fly. I suspect it was really just searching for the maximum amount of warmth.

One of the young ended up in the water and had to climb back on board.

It crawled towards its mother without letting its siblings slow it down at all.

Just before reaching its attending parent, the little bird provided us with this profile view. I love how the little wing is fully extended, even the shadow is small. Not surprisingly, most of the water ran off this bird like...'water off a duck's back'.

Compare these profiles, of our second species, with the prior three photos of species three. Do you see any differences? I think I have spotted three variations between these two similar looking types of young birds.

In all three species their bills are different, although they do resemble their parents. A second differences is the eyestripe, which in the second species extends from the eye to the beak. In species three it does not. Finally, in the third species their backs have less light markings.

Note: Immediately after the update below I will be displaying the young waterfowl with their parents. You should make your final species selections before scrolling down any further.

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While you are considering your options for species one, two and three I would like to mention that this morning I added an update to last week's post. It turns our that reliably determining the gender of a long-eared owl is much more challenging than I originally thought. You can review my latest information by Clicking Here and then scrolling down to the bold title which says, Update - 5/27/17.

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Species One - Canada Goose

Species Two - Mallard

Species Three - Wood Duck

The adventurous little bird that climbed out of the water finally found a safe and dry location - under its mother.

Have a great day on Union Bay...where young birds first feed on cottonwood seeds!

Larry



Going Native:

Without a well-funded Environmental Protection Agency, it falls to each of us to be ever more vigilant in protecting our local environments. Native plants and trees encourage the largest diversity of lifeforms because of their long intertwined history with local, native creatures. I have been told that even the microbes in the soil are native to each local landscape. My hope is that we can inspire ourselves, our neighbors and local businesses to plant native flora and to support native wildlife at every opportunity. My intention is to include at least one photo each week and visually challenge us to know the difference between native and non-native lifeforms. 






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Scroll down for answer

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This plant is considered a weed of concern in King County. In wetland areas it out competes native vegetation, it invades lawns and in rural areas it can kill livestock if eaten in large quantities. Thank you to Kelly Brenner for teaching me about this plant.









Friday, May 19, 2017

The Lioness

Congratulations to Kelly Brenner, avid naturalist and author of the Metropolitan Field Guide. Once again, Kelly has located a species of owl rarely seen in the Arboretum. This week, with the assistance of some noisy jays, Kelly found this long-eared owl. The first and only one I have ever seen in the Arboretum!

Can you guess why the name, Leo, popped into my mind?

Last fall, Kelly found this great horned owl in the Arboretum. These two owl species may look superficially similar but they are actually quite different. The long-eared owls weigh less than a pound while great horned owls can weigh a number of pounds. My Sibley-Guide says, great horned owls weigh-in at just over three pounds, while All About Birds indicates they may weigh as much as five pounds.

In both species, the feathers on their heads are not ears or horns. If what I have read is correct long-eared owls have earholes located asymmetrically, on opposite sides of their heads. The off-kilter positioning enables then to pinpoint sounds with a high degree of accuracy. The great horned owls apparently have ear holes which are located relatively close to the same position on either side of their heads. You can read more and see photos related to owl ear research at, The International Owl Center.

Being a much smaller creature, Leo would make a nice snack for a great horned owl...

...and possibly a complete meal for one of our local barred owls. Barred owls weigh approximately fifty percent more than Leo.

This may explain why Leo looked and listened carefully at the source of every little sound.

It may also explain why Leo chose to roost deep within the branches of a western red cedar. This location insured that any significant predator would have to make a quite a racket if it tried to approach Leo.

Even with small children playing in the vicinity Leo still found time to relax.

Sometimes, both eyes were closed.

Sometimes, they were wide open...

...and sometimes, Leo got by with the sight from a single eye.

Occasionally, Leo fluffed up his feathers even though the weather was fairly warm. I am uncertain if this was done to retain heat inside the cooling shade of the cedar or if it was an attempt to look as impressive as possible.

The relative length of Leo's wings was a surprise to me. Did you notice the wingtips crossing below his (or her) tail. 

Dennis Paulson has mentioned that birds with relatively longer wings tend to migrate further than birds with shorter wings. The measurements in Sibley indicate that barred owls, which are not migratory, have wings twice as long as their overall body length. In turns out that great horned owls, which are also not migratory, have wings whose length also equals twice the measurement of their bodies. 

Long-eared owls, on the other hand, have wings which calculate out at 2.4 times their body length. Not surprisingly, the range maps for long-eared owls show that each year some of them breed north of the Canadian border and some winter as far south as Mexico.

There are number of different types of migratory behavior so it could be that the long-eared owls, which breed in Canada, may winter in Washington and those which breed in Washington may winter further south, and so on. It is also possible that the ones which breed in Canada may winter in Mexico. Their precise migratory process is still unknown. 

Even Birds of North America mentions that their migration is poorly understood. It also indicates that beyond being migratory long-eared owls are also nomadic, e.g. they go or stay depending on the food they find. It seems to me that if we want to co-exist with wild creatures we must, at a minimum, understand where they live and why. (Budding scientists, please take note!)

While reviewing long-eared owl information I learned that they are sexually dimorphic. This means that there are visible differences in the exterior of the male and female birds. This effort inspired me to take another look at this close up.

If a long-eared owl has dark vertical, facial markings which line up with the center of their eyes then the bird is female. If the dark marks line up with the inside of the eyes then Sibley indicates the bird is male. It appears to be time to rename Leo to Leona.

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Update - 5/27/17:

This week my friend, Dan Reiff, pointed out that I may have misunderstood the gender-specific, long-eared owl illustration in my guide book. I primarily use 'The Sibley Field Guide to Birds of Western North America' by David Allen Sibley. The fact that Mr. Sibley states, 'dark vertical stripe through eye' under the 'Adult Female' symbol and the fact that his male owl illustration locates the stripe slightly differently is apparently just a coincidence.

After researching a half a dozen different sources I can find only one other reference to gender-based differences in long-eared owls. In Peter Pyle's, 'Identification Guide to North American Birds' he states, '...females may average darker overall, with richer buff and more heavily streaked plumage than males, but differences are difficult to access without comparison.... Reliable sexing should be attempted only with experience and, even then, intermediates (up to 50%) are not reliably sexed...'

In defense of Mr. Sibley, his illustrations of both long-eared owls and short-eared owls show the females as being somewhat darker and richer in color. This appears to be consistent with, Mr. Pyle's comments. Mr. Pyle also provides a comment about the gender of short-eared owls which is nearly identical to his statement about the gender of long-eared owls. 

The bottom line is sexual dimorphism in long-eared owls is difficult at best and it is certainly not as simple as it appeared to me when originally studying my Sibley's guide. I suspect we will never know for sure whether our long-eared visitor was best named Leo or Leona. If you have a Sibley guide you might take a look and see what you think. My apologies for the confusion.

A special Thank You to Dan for his expertise and attention to detail. 

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The fact that Leona spent a complete day sitting in a cedar tree in the Arboretum does not indicate that she is lazy. Owls are nocturnal. They generally sleep during the day and hunt at night.

Sending the day sitting in the cedar does seem to indicate that Leona is not currently nesting and most likely not feeding or protecting young. I have not seen any sign of Leona in the days since her visit. I suspect she was just passing through. I am hoping that Leona enjoys good health and a long life as she continues her journey, migratory or nomadic.

By the way, the name Leo came from the first letter of each word in the term 'long-eared owl'. It also turns out that the name Leona means Lioness, hence the title of this week's post. 

Have a great day of Union Bay...where lions migrates through the city!

Larry


Going Native:

Without a well-funded Environmental Protection Agency, it falls to each of us to be ever more vigilant in protecting our local environments. Native plants and trees encourage the largest diversity of lifeforms because of their long intertwined history with local, native creatures. I have been told that even the microbes in the soil are native to each local landscape. My hope is that we can inspire ourselves, our neighbors and local businesses to plant native flora and to support native wildlife at every opportunity. My intention is to include at least one photo each week and visually challenge us to know the difference between native and non-native lifeforms. 

A)


B)






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Scroll down for answers

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Both of these plants are native to Union Bay and the PNW. Both plants are currently blooming in the Arboretum, although the elderberry is just about done.



Recommended Citation

Marks, Jeffrey S., Dave L. Evans and Denver W. Holt. (1994). Long-eared Owl (Asio otus), The Birds of North America (P. G. Rodewald, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America: https://birdsna.org/Species-Account/bna/species/loeowl

Friday, May 12, 2017

Bullseye

Earlier this year I was pleased to observe a red-breasted nuthatch sitting upright in the sunlight on this beautiful branch. The Pacific Madrona is one of my favorite trees. I love the warmth of its smooth chestnut-colored bark. I love its waxy, ever-green leaves which continue to work through the worst winter weather. I even appreciate the dead, gnarly branches which document the tree's heroic struggle for light and life.

In the photo above the nuthatch's pose looks normal. It is similar to any number of small perching birds, but actually it is the exception, not the rule. In my experience, nuthatches are for more likely to be seen hanging upside down with their tiny little tails pointed at the sky.

For a nuthatch, looking at the ground while hanging upside down is perfectly normal.

Using one foot to hold a cone while extracting a seed is child's play.

A topsy-turvy landing on a tree trunk while caching a seed in a crevice is just as normal as eating.

A nuthatch digging a nest hole in tree might appear conventional. However unlike woodpeckers, nuthatches do not have strong stiff tails to support them while they work. They are not endowed with long chisel-like beaks and they do not have large muscular bodies to help them hammer into a snag. Nuthatches do not dwell on their lack of physical endowments. Instead, they quietly remove tiny minuscule wood chips - one piece at a time. They do require deadwood which is at least part way to a state of decay.

Even for a nuthatch, this particular nest site is unconvetional. This dead madrona branch is actually horizontal. I have tried taking photos from almost every possible angle and I have yet to find a photo which truly communicates the unique angle of this nest site. Keep in mind that while taking the following photo I was looking straight up into the nest.

This photo from last year was taken just after the nest was completed. I believe the nuthatch had already finished the hardest of the un-conventional upside down work before I noticed the nest. You might want to pay particular attention to the reddish-brown bark and the clean fresh cuts.

This year the nuthatches have done a bit of external remodeling. The branch has been dead for years, so there is no way it is oozing sap. The parents pried each drop of sap from a living tree and relocated it to this location. Some say the nuthatches add the sap to make a trap to catch insects. I suspect it may also slow down potential predators.

One thing is for sure, the sap does not slow down the nuthatches. Especially when the young are small, the parents appear to fly right through the hole and into the nest. 

They remind me of darts hitting a bullseye at a local bar. I think this one is bringing in a daddy longlegs.

As the young get older and take up more space, the adults tend to slow down and land on the lip of the nest.

This time the adult appears to be bringing back some type of larval egg.

This time the bird may be carrying a termite or an ant.

Especially when the other adult is already in the nest, landing on the lip seems like a reasonable precaution.

Being harpooned by an exiting bird would most certainly hurt.

The head of this insect looks somewhat like a damselfly, but I am not sure about the relative size. I suspect it may be a smaller insect.

Earlier in the week I watched this male Cooper's hawk observe the nest. The nuthatches stopped for a moment and considered the threat. Then both adults entered the nest. The hawk came over and sat on the top side of the branch, but seemed a bit befuddled by the gravity-defying entry hole. When three joggers flashed past under the nest, the little hawk left in a hurry. After a minute or two the nuthatches resumed their lightning fast feeding pattern.

In this case, the nuthatch appears to have secured a long insect with many rounded little segments.

This time the parent is doing a dart-like approach with a small white worm.

Earlier in the week, while the parents were still entering the nest to feed the young, their exits apparently pulled out nesting material. The grass became entangled with the sap and created a long streamer which hung down from the nest for at least a couple of hours. Inside the nest you can see one of the adults with two little green worms.

This is one of my favorite exit photos.

By Wednesday, the young were large enough to hang out at the entry way with their mouths gaping open - anticipating more fast food. Not surprisingly, the yellow outline of this bird's mouth is called 'the gape'. No doubt the bright color helps the parents hit 'the bullseye' even in the dark confines of the nest.

A young bird peering down out of the nest.

This is not a food delivery. Actually, this is the exact opposite. The young bird has turned around and delivered a fecal pouch which the dutiful parents carry away to keep the nesting area clean.

I suspect the parents will still be bringing food to the nest for a few more days.

Soon the young will be spreading their wings and leaving the nest.

Hopefully, the hawk will not be watching at that exact moment.

I wonder if the parents will be able to warn the young if the hawk is in the area.

One thing is for sure...

The parents are certainly keeping a watchful eye in every possible direction.

In honor of my mother and mothers everywhere I am challenging my readers to find at least two photos in this post in which the female nuthatch can be identified. I will point out the best two examples below.

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In Honor of Mother's Day

Here is one of my first 2017 eaglet photos, taken on May 8th. The two little heads sticking out of the nest are proof that Eva and Albert have successfully reproduced once again!

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In the two photos immediately after the fecal pouch you can easily see that the top of the female nuthatch's head is not black, like the male's head. For comparison, the male is holding the fecal pouch.

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

Larry


Going Native:

Without a well-funded Environmental Protection Agency, it falls to each of us to be ever more vigilant in protecting our local environments. Native plants and trees encourage the largest diversity of lifeforms because of their long intertwined history with local, native creatures. I have been told that even the microbes in the soil are native to each local landscape. My hope is that we can inspire ourselves, our neighbors and local businesses to plant native flora and to support native wildlife at every opportunity. My intention is to include at least one photo each week and visually challenge us to know the difference between native and non-native lifeforms. 

Which types of trees do you see in these photos and are they native to Union Bay?

A)

B)

C)






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Scroll down for answers

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All three of this week's trees are native to Union Bay and the Pacific Northwest. Somewhere I read the Pacific Madrona is actually called Pacific Madrone when you are outside the Pacific Northwest. Either way you say it, it is the same beautiful tree.