Saturday, August 14, 2021

Poison in the Pond

Thursday morning, this Barred Owl stretched its wing on a branch overlooking a silent seep of water in the freshly revitalized Rhododendron Glen. I was a bit surprised to see such extensive molting of the feathers on its head. It is the right time of year for molting, but I would have expected that only first-year birds would replace so many feathers all at once.

Although Barred Owls usually hunt at night they can become instantly alert during the day. I suspect the younger and less-skilled owls are more likely to still be hungry after sunrise. Given this owl's position above the moisture and its level of alertness, I assumed it was still hunting and hoping for food.

Barred Owls are carnivores. They will eat a surprising variety of creatures. During daylight, they will most often sit and doze close to the trunk of a coniferous tree. If an enticing sound reaches their ears they are likely to open at least one eye to evaluate the situation. If it looks promising, they may silently stretch before dropping from the overhanging branch. Silence and surprise are critical skills for a Barred Owl. They even have specialized feathers that help mask the sound of their approach.

They primarily hunt in forested areas. However, they prefer an open understory below a protective canopy. (Bald Eagles, Great Horned Owls, and Common Ravens will eat or compete with Barred Owls.) 

Even among the trees, Barred Owls require space to spread their wings. Their mature wingspans are normally greater than three feet. They are especially fond of hanging out near water since all of their favorite foods like to drink.

Barred Owls do not participate in annual migrations but our local owls are the offspring of immigrants. Originally, Barred Owls were primarily found east of the Mississippi, as generations passed they slowly moved west via Canadian forests and then south through the Cascades. Click Here to see a dynamic display of their annual sightings. I suspect the limited summer movement may be primarily due to younger birds looking for mates.

They are territorial. A pair of mated birds will have overlapping territories. The overlap is nearly 100% during the breeding season and potentially half that during the winter.
 
After being chased by crows, the mate of the owl above moved from this perch into the dense shadows of a Western Red Cedar. Curiously, the feathers on the head of this owl showed no signs of molting. The variation between the two made me wonder if the first owl might still be somewhat immature - perhaps in its second year?

In any case, when I looked closely at the trailing edge of the primary wing feathers of the first owl, I could see evidence of wear. This reinforced the idea that this owl was more than a few months old and most likely it did not hatch out this year. 

Also, I saw a pair of Barred Owls in this same area this Spring. Normally one of a mature pair would have been in a nest on eggs at that time of year. This memory also strengthens the idea that one of these owls might be old enough to find a mate but not yet ready for family life.

The owl occasionally attempted to doze. 

I love the feathered eyelids. Barred Owls are capable of surviving temperatures far below those they encounter around the Salish Sea.

Soon, a hummingbird spotted the owl and began diving back and forth above its head. When the hummer stopped to rest for a moment, further out on the same limb, I finally caught a photo.

Our hero immediately awoke and moved closer to the hummingbird.

I suspect the intensity of its focus may have been correlated to its level of hunger.

The owl watched the hummer from the beginning of each dive...

...all the way through to the end. In my experience, most mature owls usually ignore hummingbirds.

Ultimately, the owl coughed up a pellet, the remains of its last meal, and flew to a more secluded and protected branch - just below its mate.

Earlier in August, some friends and I spotted a Barred Owl about one hundred yards to the north. Given the lack of molting feathers on its head, I suspect it was the mate of our hero.

It also snoozed for a time. Then suddenly, it dove from its perch and into the Salal. 

There was a considerable amount of scurrying but the owl came up empty.

Both the Barred Owl and I could hear the rapid calls of a Douglas Squirrel overhead on the branch of a Western Red Cedar. The owl moved closer but apparently realized that without the element of surprise there was little point in chasing the speedy squirrel.

The Douglas Squirrel, unlike most other small creatures, did not run and hide. It did the opposite. It spent approximately 10 minutes verbally abusing the Barred Owl. I could not comprehend the "words", however, the gist of the message was pretty obvious. It was scolding the owl for being rude. It may have mentioned being slow and unskilled as well. Perhaps it finished by advising the owl to take its appetite elsewhere.

A few days before, I spotted a Barred Owl staring into the lower Woodland Garden pond. It was early in the morning and we were undisturbed. Abruptly, the owl descended towards the water - much faster than I could react. There was a very brief splash, hidden behind a bush, and then the owl rose up to a branch on the far side of the pond. Briefly, I saw the shadow of a wiggling shape - trying to escape its talons.

In the past I have seen an occasional non-native goldfish, a non-native bullfrog, and native Northwestern Salamanders in the Woodland Ponds. Many times I have seen the Barred Owls hovering just above the water's surface but never before had I seen them catch anything.

By the way, please do not put non-native lifeforms in our waters - the native creatures already have more than enough imported competition.

Speaking of things a Barred Owl will eat:

About a week before the pond encounter, one of the Gardeners pointed out a Barred Owl eating a good-sized rabbit in the southern part of the Arboretum. When eating larger creatures, Barred Owls always start at the top. 

Apparently, an American Crow is large enough to require the head-down approach as well. Click Here to read a post about a young owlet getting to eat crow.

Rats are probably their most common meal and approached the same way. Click Here to read about the more effective alternatives to rat poison.

If the creature is small a Barred Owl will simply swallow it whole. Later, they regurgitate the inedible parts and leave a pellet of fur and bone to fertilize their surroundings. Click Here to read about a young owlet's early hunting success.

Barred Owls will even feed worms to their young. I suspect in the case of worms they do not distinguish between the head and the tail. However, it was not a worm that the Barred Owl pulled from the Woodland Garden pond.

The Barred Owl tossed its head back and swallowed the mature native Northwestern Salamander in a single gulp. These native salamanders exude a poison that helps protect them from some predators. It does not appear to be effective with the Barred Owls.

I suspect this owl and its mate are a separate pair from the two at the Rhododendron Glen. I have seen no indication that either pair reproduced this year. It will be very interesting to see what happens next year. Will both pairs begin reproduction? Will they have territorial battles given their close proximity? Will there be enough food to feed both pairs and all their potential offspring? 


A Parting Challenge: 

This paragraph is about the first pair of Barred Owls in this post. I am thinking the best names for them are Wolly and Dawn. The logic behind these names will be explained below in the Going Native section. However, if you would like a challenge you might skip the explanation and try visiting the Rhododendron Glen in the southern part of the Arboretum. If you pay close attention you should be able to find the clues to my inspiration. Good Luck!

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

Larry

ps: Birds of the World is an excellent online resource.

Recommended Citation

 Mazur, K. M. and P. C. James (2020). Barred Owl (Strix varia), version 1.0. In Birds of the World (A. F. Poole and F. B. Gill, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.brdowl.01

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.)

Another idea that integrates perfectly with living in harmony with nature is the concept of Forest Gardening. Apparently, Native Americans collected and nurtured dense multi-layered gardens of native herbs, plants, shrubs, and trees that produced food and herbal medicines. Even after 150 years of no maintenance, the gardens are essentially intact and the diversity of life remains significantly higher than in the surrounding forests. Click Here to learn more.



To what species' do the following two trees belong? 
A)

B)
Are they native to Union Bay?











Scroll down for the answer.









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In the early part of the 20th century, both of these trees were only known to scientists from fossils. Later, both were discovered to still be alive and well. These trees are not invasive and having them in the Arboretum helps to create a genetic reserve in case a forest fire or a pest infestation should happen to destroy them in the lands where they originated. 



These trees are the inspiration for the names Wolly and Dawn. The owl in the first photo was sitting on a branch of a Dawn Redwood. 

It is curious to consider the owl sitting on the branch of a tree in Seattle. 100 years ago the owl species was only found in the eastern part of the United States and the Chinese tree species was only known as a fossil in North America.



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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. Google never responded to my requests for help with this issue. Now, in 2021,
 the service is being discontinued.


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, 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




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A final photo:
The Barred Owl, from our first photo, flying to perch near its mate. 
















 




 

1 comment:

  1. I love you posts- beautiful, fascinating photos illustrating your interesting detailed information and fun humor. Thank you!

    ReplyDelete