Walking Tour

Virtual Walkthrough of My Ravenna Park Site Findings

     Located just outside of the University of Washington campus is Seattle's beautiful Ravenna Park. I've been observing the ecology and organism behavior at a number of points along the park's trail system beginning beneath the 20th ave NE bridge, so here is a virtual walkthrough of a just a few of the native plant, animal and invertebrate species as well as other natural occurrences that can be found here. 

    

     Follow along the numbered route while reading the corresponding descriptions to see what I found interesting throughout the park!

Point 1: Geomorphology 
Ravenna Erratic

This large boulder, probably upwards of 50 cubic feet, was deposited by the Vashon Lobe as part of the Cordillerian Ice Sheet, which covered the Puget Sound region at one time. Located by the small stream running through Ravenna Park, it has a plethora of mosses and lichen growing on it which are thriving I might add. This boulder has its own ecosystem living on it, which is mostly comprised of invertebrates such as mosquitos and their larvae growing nearby. This landmark of the park stands out as one of the only large rock formations in the area and is located right beneath the 20^th ave NE bridge. I’ve seen many a person from our ENVIR 280 course using it as one of their site locations for its uniqueness. This stone will be here for generations to come and I hope people can appreciate it for its specialty in that we don’t see many like it in our area due to Seattle’s industrialization and removal of such formations. I’m grateful for the city park system and its preservation of such beautiful formations in a city that is so characterized by a city landscape, especially near the University of Washington.

Point 2: Birds

I have come to realize Ravenna Park is absolutely full of bird life during the season of Spring. Species I have seen there over my weeks of observations here include the Song Sparrow, Black-Capped Chickadee, American Crow and Brown Creeper. If you stop to listen, you can here all the different calls mixing over the sound of the stream running through the park; it's pretty relaxing. It's especially nice knowing some of the songs so that I can identify the individual species flying around. The Black Capped Chickadee see in the picture below was difficult to photograph because it was skittish when I got near. However I persevered and captured one, almost getting what appeared to be its mate in the picture as well. Finding the Barred Owl feather below was a treat; it was interesting to observe the design of its wing feather and its serrated edges used for silent flight. I'm sure they have a field day on the local squirrels and other rodents when it gets dark in the park. Lastly, I observed a Brown Creeper building its nest in the outer layer of bark on a tree trunk. It seemed like a safe place to raise young considering it was a good ten feet up the tree where few predators could reach.

Point 3: Plants

Top: Most recent
Bottom: First Site Photograph

The Giant Horsetails have overrun my site! At the beginning of this course my location in Ravenna Park had multiple species of trees and shrubs, including thimbleberries, sapling Douglas Firs as well as Skunk Cabbage also known as Swamp Lantern which I heard about on my field trip in Seward Park. This area has become a refuge for so many organisms like millipedes, mosquitos, and different species of birds like the song sparrow. On top of these, I’ve seen grey squirrels feeding in this area on seeds and nuts. They are interesting to observe because they have so much energy. Back to the giant horsetails, I might add that they seem to be the most dominant species for their ability to not only colonize the area in terms of succession but also have sustained their dominance in the area. I’m curious to see how far they still have to grow because they show no sign of slowing down. I would also be interested in witnessing the other species they continue to push out of the location. In my site, there are also plants such as Western Red Cedar, Western Hemlock and Salmonberry. There seems to be no limit to the extent that the Giant Horsetail can grow. 

Point 4: Invertebrates

Along with multiple spiders, there were plenty of mosquitos flying around. I took a photo of one of them feasting on my arm just so I could see it more closely and study it. Looking very closely, I was able to notice far more intricate design patterns than I would expect from a mosquito. Its black and gray stripes were actually quite aesthetically pleasing considering the organism I was looking at was sucking my blood. All in the name of science, right? I didn’t see any larvae, but they are so small and I would guess that they have to be spawning in the marsh-like ground beneath the giant horsetails where they would have plenty of protection from predators or disturbances. Other invertebrates I found at my site included a millipede, several spiders, as well as some small black ants. There were also a number of black cedar beetles that would meander along the ground until they came to a suitable hiding place. When I would remove their cover, they would immediately begin to crawl at pace to the next safest spot. It is interesting to see all of these different types of bugs coexisting with very little evidence of competition or predation aside from the set of spider webs on the tree. I’d be interested to get to see some examples, as I know there has to be more going on than meets the human eye. There were also multiple honey bees buzzing around as they pollinated the various flower species like the thimbleberries that were all over the place.

Point 5: Lichen/Fungi

There was a brown shelf fungus growing on a Bigleaf Maple and it was thriving. There were multiple occurrences of this interaction on different levels of the tree. The fungus was extremely rigid and hard, seeming to not have any intention of releasing from its substrate. When prompted, this fungus produced no spores and beneath its cap there were no gills. Along with the shelf fungus, there were multiple other fungi and lichens at my Ravenna site. Others included examples of foliose, fruticose and crustose. Pictures are displayed below. The lichen at the site seemed to be doing well and had plenty of nutrients to feed on as they grew without limitation all over the place. The color scheme of these growths was a variety of greys greens and white. Spores ranged from black to different shades of grey so they didn’t differ very much. It was quite interesting to witness the differences in fungi and how well they could coexist in such a small geographical range. They seemed to be most prominent on nurse logs that had plenty of nutrients to offer their accomplices. With such a wide range of fungi it is difficult to identify them all, however I feel that with time I will grow more proficient at it.

Point 6: Ecological Interaction

I observed a spider web with a number of other invertebrates caught inside. Woven between the split portions of a tree trunk was said web, and there were multiple examples of this at different elevations along the Bigleaf Maple. If I had to guess, I would expect that this spider species thrived in old growth forests where it could create its powerful webs and trap invertebrates that were unsuspecting of the snare as they searched for food along the trunks of trees. What was interesting to observe, was the size of the spider I presume to have built the web compared to the expanse and thickness of its trap. It is possible that it wasn't the spider shown below because I only saw it near the web, never on it, but I'm not sure. On parts of the web, there were thick globs of a shiny mucus-like substance that improved the catch rate of prey. I've never seen this substance before on a spider web though so it left me wondering if this was a trait specific to this species of spider. Another thing I found interesting was the lack of diversity in spiders. The one shown in the picture was the only one I saw during my whole time of observation. Perhaps with more intent on finding them I would be successful, but usually spiders are not hard to find in an area with so much detritus and so unaffected by humans, relative to more urban areas that is.

Point 7: Ecological Disturbance

Sitting right within my original site area, there are multiple fallen trees whose roots are completely overturned. This disturbance occurred most likely from a lack of soil stability in that it is muddy and marsh-like, as well as high winds at times. It was very convenient because the tree trunk provided a bridge of sorts sitting above the muddy floor of my meadow site, so I was able to walk across and take photos from there, as well as observe organisms from a higher standpoint. What I found interesting was that there were no species colonizing the newly exposed soil where the tree roots once were. If I had to guess I would bet that the tree took with it many of the important nutrients for plant growth in the top soil still attached. Wrapped in the root system were stones, as well as a lot of residual soil. I looked for examples of a mycorrhizae system within the roots but to no avail. Perhaps this tree species is not one that the fungus is able to exist within. One thing the fallen tree's empty spot did allow for though was a thriving miniature ecosystem for invertebrates. In the nooks and crannies where the roots were once deep in the ground were tons of spiders, ants and millipedes. I would be curious to see which species eventually controls the area now that a new succession is occurring.


Point 8: Animal Behavior

Along the main trail of the park, I was able to catch a few glimpses of a Grey Squirrel jumping and climbing around in the tree canopy. Not long after I saw this one, another approached it, and as they stared each other down they both seemed ready to pounce at any minute. Soon they were chasing each other around the trunks of trees, whirling around so fast that I couldn't tell them apart. Because it is Spring, I assume they may have been taking part in a courting ritual, and at some point after chasing around they would mate or potentially already have. After watching them do this for a while, they began to calm down and I watched one of the squirrels climb up and down the trees and horde some kind of nut or seed in this stash in the picture below. From the front entrance it seemed to not go very deep, but I watched one enter, then a minute later exit from a different hole beneath the same tree. I didn't know squirrels that spent most of their time in the trees would hide food underground but it makes sense considering the limited places to store food up in the branches. All in all these were probably my favorite organism to observe in the park because of their sheer energy and ability to climb a vertical surface so quickly.

Point 9: Stream

Every time I came to visit and observe my weekly site, I would travel along a small stream running along the main trail of the park. The stream stems from the local Greenlake area and continues after the park throughout more of Seattle. Along the banks were various water intensive species like salmonberry,  sitka spruce and pacific willow. I looked for any fish that may have been hiding in the shadows or around the stream;s edges but found none. Another species that did seem to love the proximity to the water were the native ferns bracken, western sword, licorice and lady ferns. These were the most common species growing near the water and their leaves would sometimes dangle into the shallow water. Here and there throughout the park, I could see where the groundskeepers had adjusted the path to navigate through the way they wanted. There are small bridges for crossing throughout so that people can get close and enjoy the running water as they explore Ravenna. There were also many logs placed in the path of the stream to avoid washing out of certain areas and they seemed to be doing their job well. The parks department has done a great job at creating a space that is naturally appealing while still being functional for joggers and others to enjoy.

Point 10: Land Use History

Ravenna Park has a long history ranging back to the 1800's when Seattle had a booming logging industry. However, Ravenna was one of the lucky areas to escape the cutting, therefore enabling it to display a rich example of old growth forest mainly comprised of Douglas Firs, alders and cedars. The cut log stump displayed below shows one that had been cut down to make room for the public city park which was installed around the year 1900. Now the park doubles as a natural observatory for anyone interested in the field and wishes to do research on native plant and animal species, while also allowing for a steady stream of visitors who wish to use its sports and playground facilities. When I spoke to a park employee he said that they have a full staff working every day to maintain it and keep it enjoyable for visitors. Positions included ecological specialists to make sure the plants stay healthy as well as general groundskeepers who shape the paths and inorganic aspects of the park to fit smoothly with the organic portions. Hopefully the park is preserved for years to come and people can continue to enjoy a place where parents, children, plants and animals can coexist and the field of natural history can be available for all in Seattle who want to get a taste of the outdoors in a very much urbanized               location otherwise.

For more information on Ravenna Park history see: http://www.historylink.org/index.cfm?DisplayPage=output.cfm&file_id=9559