In 1916, with the creation of the Montlake Cut, Lake Washington dropped roughly 9 feet. Foster Island suddenly grew from two to ten acres. The soil of the newly revealed lake bottom attracted a variety of flora and fauna, some native, some not. Around this time osprey were still nesting on Foster Island.
Today, thickets of Himalayan blackberries, ivy, bindweed and holly bushes tend to dominate the understory. The ivy climb and kill the native big leaf maple, cottonwood and red alder trees. The blackberries tend to 'drowned' the native sword ferns, Indian plum, Oregon grape and horsetail.
In the Arboretum portion of the island, red oaks introduced from the eastern United States, drop a steady supply of acorns.
Not surprisingly, the non-native acorn-eating eastern gray squirrels have become the primary mammal of Foster Island. A few years ago I ran into a man who said that when he was young, native squirrels did exist on the island. Today, all I see are the eastern grays.
The water surrounding Foster Island has similar issues. The native painted turtle, on the left, competes with the non-native red-eared slider, on the right. (Thanks to Dennis Cheasebro and Dennis Paulson for pointing out the differences. See last week's comments for more details.)
I am always glad to see native great blue herons, pied-billed grebes and others feed on the oriental weather fish. However, the birds do not seem to be able to keep up with the supply. Originally, weather fish were used to keep aquariums clean. Somehow they were dumped into Lake Washington and now they stir up the water and make it difficult for native salmon, like the Chinook, to reproduce.
The dense mat of fragrant water lilies are also non-native. They were reportedly introduced during the Alaska Pacific Yukon Exposition in 1909. Sadly, the lilies block the sunlight and reduce the oxygen needed by native aquatic creatures.
Lucky for us, during the last year the tide has begun to turn. Native plants are taking root in the south central portion of the island. The plantings were funded by the environmental remediation related to the northern portion of the new 520 bridge.
The fall foliage of a native vine maple, planted as part of the remediation.
The native cape jewelweed is another one of the 520 plantings. These beautiful little flowers attract a lot of attention, in part because this time of year the flowers of most other native plants are long gone.
Update: as of September 25, 2017
I have been considering Jewelweed a native plant (Impatiens capensis Balsaminaceae) because it was listed as such in the book 'Wildflowers of the Pacific Northwest'. I just double-checked the original and the revised editions of 'Plants of the Pacific Northwest Coast'. Both copies state that Jewelweed (Impatiens Noli-tangere) is an asian ornamental which has become established in the PNW. Live and learn. Larry
Updates: as of September 28, 2017
The United States Department of Agriculture shows Jewelweed, Impatiens capensis Meerb., as native to Washington state.
Finally, the best information I have came in an email from our local and renown author, Arthur Lee Jacobson. Mr. Jacobson sent me an excerpt from his book, Wild Plants of Greater Seattle. Arthur states,
'Orange Jewelweed....(Impatiens capensis = I. biflora, I. fulva)....hails from eastern North America....The epithat capensis alludes to the Cape of Good Hope, since it had been mistakenly believed to be native there when it was introduced to Europe and named in 1775.'
I have gone back to each source and noted (and included) their scientific names. I believe my confusion about the status of this plant stems mainly from the multiple different varieties. This is clearly a case where paying attention only to the common name is insufficient. I certainly appreciate Mr. Jacobson's guidance!
This is my best guess at the bee's perspective, but in reality the bee can see spectrums of light which are beyond our capabilities.
Sometimes the flowers attract multiple visitors who have to take turns.
I must admit that these are non-native honey bees, however in a world where pollinators are struggling to survive, I am always happy to see heavily loaded little bees. I have also seen hummingbirds visiting the jewelweed. So far the little birds have been too quick for me.
My biggest surprise was spotting this native pacific tree frog resting among the new 520 plantings. This is the first one I have photographed on Foster Island.
A moment or two later, I noticed a second frog watching from a slightly higher perch.
Tree frogs come in a variety of colors and can even slowly change color when need be.
I watched this tiny ant climb all over the frog.
I thought for sure the ant was a goner when it crawled in front of the frog. Instead, the little one-inch-long frog never stirred and the ant safely crawled onto the next leaf and continued on its way. The only explanation that seems to make sense to me is that tree frogs feed primarily at night and evidently this little frog was full.
I am happy to report that I have heard a pacific tree frog calling, from among the new native plants, twice more in the last week.
Later in the week, I was disappointed to learn that the next portion of the 520 bridge construction will require another working bridge to be built. This time it will be on the south side of the old 520 freeway. Once again this will require clearing trees and vegetation all the way across the island. At a minimum, I certainly hope that this new construction will require additional and expanded native plantings on Foster Island.
I also noticed this oddly bee-like fly among the 520 plantings. Even though it has black and yellow stripes like a bee it only has two wings (instead of four) so I believe it is a fly. I love the bronze thorax.
I would think the large brown eyes should make it easy to identify. None the less, its name has eluded me so far.
My parting shot for this week shows a glimpse of a native warbling vireo. It apparently stopped on Foster Island for a snack during its migration to a warmer winter climate.
After closer inspection my friend and Master Birder Marcus Roening pointed out that the bird in my last photo is too yellow for a warbling vireo. Plus, the upper beak lacks the very slight down turn at the tip that a warbling vireo would have. Which means this bird is actually an orange-crowned warbler. Sorry for my confusion.
I certainly hope that we are able to watch and support a steadily increasing invasion of native plants and creatures on Foster Island!
Have a great day on Union Bay...where nature lives in the city!
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. Can you identify these Foster Island plants?
Scroll down for the answers
A) English Ivy
B1) Holly (Center)
B2) Bindweed (Lower Left)
C) Oregon Grape
The A and B's are non-native plants. C is a native shrub.