UBNA Walking Guide

Welcome to Emily's UBNA Walking Guide!
Union Bay Natural Area is right on the University of Washington - Seattle campus, near the IMA. Here's the address: 3501 NE 41st ST Seattle, WA 98195. My observation site is at the most southeastern corner of UBNA.
The map below marks ten different stations to explore (station information is below). Enjoy!

Station #1: Invasive Species

English Ivy

Union Bay Natural Area has an exciting potpourri of Pacific Northwest flora and fauna to explore! Before we dive into the biodiversity, we’ll first differentiate the native and the invasive species in this station. Invasive species are often species introduced to an environment, but most importantly, they harm the habitat they reside in. Feel empowered after visiting this station to clear away (most of) these pests. Firstly is English Ivy (Hedra helix) (see picture at right), a common plant used for decoration. It is a climbing plant with five-lobed leaves and a rapid colonizer. English Ivy is especially dangerous when matured because it grows to high density, adds weight to a plant, reduces the plant diversity, and destroys native habitat. You’ll see that it has grown along the trunks of every Black Cottonwood at the site, no matter the age of the tree. The second example is Himalayan Blackberry (Rubus armeniacus), which is found in prickly thickets with red stems and white five petal flowers. While they produce delicious red to black berries in the summer, they can be a nuisance because they displace and shade out native species. It is almost impossible for any other plant to grow at the base of the Black Cottonwoods because of the heavy Himalayan Blackberry thickets. The Himalayan Blackberry can also damage native plants (see picture

Himalayan Blackberry

at left), such as the torn branch on the cherry tree. Despite its dominant nature, Himalayan Blackberry can be a paradox because it also provides habitats for birds and filters sediments from stream overflows. The third nuisance is the Yellow Iris (Iris pseudacorus). It is a prolific grower in wetlands, often almost submerged in the water and found growing with Cattails. The leaves are erect with a bright yellow flower that blooms around May. The Yellow Iris can reproduce through a massive root system and water dispersed seeds. This gives it a great growing advantage and causes the Yellow Iris to displace the native plants, which are unable to compete and grow at the same rate.


Station #2: Lichen and Fungi

Turkey Tails

Hammered Shield Lichen

There’s the cliché that one should “stop and smell the roses,” but at this station, the motto is “stop and taste the fungi.” Did you know that one way to identify fungi is by taste (not eating)? Of course, for the less daring, there are other characteristics to look for as well. One fungus that is found at my site is the Turkey Tails (Trametes versicolor) (see picture on right), which is tucked away in the Himalayan Blackberry thickets. The Turkey Tails are polypore fungi, which mean the underside of their fruiting bodies (the “mushroom” resembling portion you see) is composed of many pores or tubes. The fungus has rings of different colors (often rusty brown and some green, which is actually algae) and its shape also resembles the tail of a wild turkey, hence the name Turkey Tail. The Turkey Tails at my site are growing upon a dead log. Growing on a nearby dead log is some Hammered Shield Lichen (Parmelia sulcata) (see picture on right). It is a foliose lichen, so it looks leafy, and as the name suggests,

Mica Cup

the surface of this lichen looks like it has taken a beating from a hammer because each lobe has many ridges and depressions. This lichen grows in small patches across the log. Another fungus that has recently sprung (around the end of May) is Mica Cup. It is found among some leaf litter at the base of a Black Cottonwood because it is growing near the underground root of the Black Cottonwood. The Mica Cup (see picture on left) grows in clusters and if you look underneath the cap of the mushroom at the gills, you can tell the age of the mushroom. If it is still young, then the gills are a light brown color, but as the spores of the mushroom mature, the gills will turn black. So far, as of late May, the gills are still a brown color.

Station #3: Plants

Black Cottonwood Branch

You’ll find some of the most classic wetland species at my site, especially at this station. First, look up. The foliage that is either offering you some shade or providing you coverage from the rain is the Black Cottonwood (Populus trichocarpa).  Part of the willow family, the Black Cottonwood is usually found near streams and wet forests, so this shore of Lake Washington is a perfect spot for these large Black Cottonwood trees to thrive. You may know them better as the irritating allergen that produces the cotton-like seeds, which swept through Seattle during May. The Black Cottonwood can also be identified by its leaves that are

Bitter Cherry

heart shaped (in other words, ovate) (see picture on right). Tucked between the Black Cottonwoods is a smaller tree called Bitter Cherry (Prunus emarginata) (see picture on left). Also a common sight at riparian forests, it produces clusters of five petal white flowers in April. It was actually the first flowering plant at my site. The easiest way to identify this as a Bitter Cherry tree is to look at a branch and look for a small red gland at the base of the leaf. If you turn to look at the marsh area, you will see more canonical wetland species. There is another willow, the Pacific

Pacific Willow

Willow (Salix lucida). While willows often hybridize and are difficult to identify, the Pacific Willow is the only one I have seen with yellow colored twigs, which makes it unique. The Pacific Willow at my site is a young shrub that only began growing a month ago (April) (see picture on right). On the surface of the water you will see Yellow Pond Lilies (Nuphar lutea) floating. As of late May, they have not bloomed yet (the yellow flowers are a cup shape), but the lily pads are quite large, up to a foot wide. In the distance you will also find Cattails (Typha). As you will see in a future station, these Cattails are home to many birds.

Station #4: Invertebrates

Let’s return our view back to the base of the Black Cottonwoods because there is more to explore, especially in terms of invertebrates. If you dig a little into the leaf litter, you

Pill Bug

will find immediately some Pill Bugs (Armadillidium vulgare) (see picture on left). Most likely, you will find the Pill Bugs curled up in a defensive posture because you have disturbed them. When curled up, you can appreciate the intricate gray plates of the Pill Bug. Do note that the Pill Bug is actually a crustacean and not an insect! Another interesting invertebrate to look for are the Meadow Spittlebugs (Philaenus spumarius). The adult Meadow Spittlebugs are hard to see with

Meadow Spittlebug

the naked eye, but around mid-May, you will see them in the form of a milky white foam at the base of leaves and branches of grasses and sedges (see picture on right). This is the nymph form of the Meadow Spittlebug and it is hiding in the foam, protected from predators and the environment’s varying temperatures. In early May on a sunny day, if you wait patiently enough, you may find a

Mourning Cloak

Mourning Cloak (Nymphalis antiopa) resting on the gravel trail with its wings spread out (see picture on left). It is a charismatic butterfly with brown colored wings and a white border along the edge with blue spots. If you can get close enough, notice how subtly the antennas move up and down as the Mourning Cloak senses its surroundings.

Station #5: Birds

Female Mallard and Ducklings

You’ll hear the birds the minute you enter Union Bay Natural Area, but there’s a few birds that you can commonly spot! The first is the Mallard (Anas platyrhynchos). There is a Mallard couple that has built a nest in the middle of the marsh area. The nest is quite humble consisting of a depression in the moist ground and some grasses and leaves from nearby. Just recently (late May), I saw at least six ducklings swimming in a single file behind their mother (see picture on left). I have seen the same Mallard couple all quarter and at other times, you will see them dabbling. The Mallards have a broad beak and instead of diving into the water to catch prey, they tip forward into the water (so their behind sticks out of the water) and forage for food.  Another common sight is the Savannah Sparrow (Passerculus sandwichensis) (see

Savannah Sparrow

picture on right). This small songbird is easily identified by a yellow stripe over its eye. This is initially a little hard to look for without a pair of handy binoculars. At my site, they are often found on the trail or perching on apple trees just out of my site. Another bird has also recently (late May) taken residence at my site. A Black-capped Chickadee (Poecile atricapillus) (see picture below) has built a nest somewhere among the Himalayan Blackberry thicket. It has been pecking at branches and bringing them into the thicket. As the name suggests, the Black-capped Chickadee

Black-capped Chickadee

Great Blue Heron

can be identified by a black cap and it also has white cheeks. It's an adorable bird with a short neck and large head. On a lucky day if you’re at my site early in the morning, you may catch a glimpse of a Great Blue Heron (Ardea herodias) (see picture below). This majestic, blue-gray bird has long legs and neck, and looks shaggy in appearance. Even though Great Blue Herons usually nest in trees, I believe the Great Blue Herons in my site are ground nesting and they have built a nest somewhere far among the Cattails because they always stalk in and out from the same general location.

Station #6: Ecological Interaction between Species

There are two more wetland bird species that you will learn about in this station because of their close knit interaction. The first is the Red-Winged Blackbird (Agelaius phoeniceus). The males are easy

Red-Winged Blackbird

to identify as they have glossy black feathers with red epaulets bordered with a yellow color. If you look at the top of the tall snag in the midst of the Cattails, you can probably find a male Red-Winged Blackbird perched there surveying its territory (see picture on right). The second is the Marsh Wren (Cistothorus palustris). These small birds are a little harder to spot because they are always hiding amongst the Cattails and they are a brown color, much like the Cattails in the area. If you patiently look at the marshy shore, you may find a Marsh Wren feeding with its tail cocked. So, what’s the relationship between these two species? As you may have noticed, the two species reside in the same area, which can be problematic. In fact, Marsh Wrens are known to destroy the eggs and young of Red-Winged Blackbirds because they both create nests among vegetation in marsh areas(3). On a rare occasion, you will hear major rustling and specific aggressive calls occurring from the Cattails and while you cannot see exactly what’s occurring, one can speculate that it is a confrontation between a Red-Winged Blackbird and Marsh Wren. Luckily, these confrontations do not occur often because Red-Winged Blackbirds favor sparser vegetation, whereas Marsh Wrens favor denser Cattails. In addition, you will often see multiple female Red-Winged Blackbirds fly into the same general location among the Cattails because they have developed a cluster nesting strategy, which protects the young from the Marsh Wrens. Not all is calm on this front!

Station #7: Geology/Geomorphology

And now for a history lesson at this station! Union Bay Natural Area used to be a part of the Lake Washington (see picture below), completely underwater. Even before that, this area

Lake Washington

was carved out by the Puget Lobe of the Cordilleran Ice Sheet (1). Imagine this area under 3000 feet of snow! Underneath the snow were outwash plain deposits that exist because streams derived from the glacial front carried sediment and deposited the sediment at the toe of the glacier. As the glacier advanced, the outwash plain deposits would be buried underneath. As the Puget Lobe receded, a glacial lake called Lake Russell was formed and underneath, the outwash plain deposits lay buried, ready for growth. Clearly, glaciation has resulted in lasting impacts on Union Bay Natural Area. In 1916, the Lake Washington Ship Canal was constructed,

Outwash Plain Deposit

which lowered the water level of Lake Washington(2). As a result, the outwash plain deposits at the bottom of the lake became exposed at shallower areas, including Union Bay Natural Area. This fertile soil was subsequently colonized by many of the wetland species you learned about in station #3 (see picture on right) and formed a marshland. It was not a smooth transition from exposed soil to wetland habitat, but we will discuss this further in station #9 when we talk about land-use history.

Station #8: Animal Behavior

If you stare at the marsh area for a little bit, you may be unnerved to occasionally see air bubbles rising to the surface of the water. Not to worry, there isn’t a monster down there, but in fact some peaceful Eastern Painted Turtles (Chrysemys picta picta). These turtles are merely in the mud hunting for food. I once saw one with a shell that was a foot and a half long and mistook it for a patch of mud until it slowly moved. The turtles hunt along the bottom of

Eastern Painted Turtle

the marsh and jut their head in and out of vegetation to agitate prey. On a rainy day, you should pay close attention to the marsh in order to spot a turtle because they are good at camouflaging themselves in the mud. If it is a sunny day, you will have much better luck finding and watching the turtles. Their dark colored shell is very smooth and they can be easily identified by yellow lines on their head, neck, and legs. Sunny days are the best days to look for these turtles because they are cold-blooded

Turtles basking in the sun

reptiles. This means they regulate their body temperature based on the environment and for warmth, they must bask in the sun. For this reason, no matter the time of the day, I always seem to see the turtles basking in the sun. On the far log you will often see a group of turtles basking in the sun (see picture on right). They will stretch their neck and stick it up as high as possible. This allows them to increase the amount of surface area that is exposed to the sun. This position also allows you to easily identify the turtles because their yellows stripes will be clearly visible. When they have warmed up enough, you will see them walk towards the edge of the log, tuck in their appendages and head, and drop back into the water to hunt for food.

Station #9: Land-Use History

Random garbage from the former landfill days

Union Bay Natural Area (including my site) was not always a glorious location. After the outwash plain deposits were exposed because the water level had dropped, the city of Seattle and the University of Washington decided a new fate for this land. They began dumping residential waste into the area and converted it to the Montlake Landfill around 1926. In 1971, the landfill was closed and capped with two feet of clean soil. Some areas were landscaped and additional topsoil was added. In 1972, Union Bay Natural Area was converted into a wetland habitat for educational and recreational purposes and was transformed into the beautiful landscape you are standing upon today(2). While the history of the area has been covered and hidden underground, the signs of previous human abuse still remain. As you stand at this station and enjoy the views of Lake Washington, it is highly probable that you will find some trash floating along the shore (see picture on left). In addition, you may smell some methane gas from the decomposing landfill debris, but don’t worry, the quantity is quite small and does not pose a hazard. This site is a view to behold, but keep in mind, there is a deep, dark secret hiding underneath.

Station #10: Ecological Disturbance

Toppled Black Cottonwood

Around mid-May, thunder and a strong windstorm struck my site, and the result is the focus of this station. A large Black Cottonwood tree has toppled over (see picture on right). It was upturned, so its roots are now exposed. The tree must have been in a precarious position because someone has sawed off parts of the tree and left it nearby. The upper branches are blocking the flow of the water between Lake Washington and a little marsh nearby. The water in the marsh is now stagnant and home to many gnats. It will also be more difficult for birds (especially dabblers) to swim into the marsh area, so this is one less

Upturned roots of Black Cottonwood

food source at Union Bay Natural Area. Furthermore, this marsh was part of a male Red-Winged Blackbird’s territory. I haven’t seen the male Red-Winged Blackbird since the disturbance, so he may have had to find a new territory.Quite a few nests could have been destroyed during the fall of the tree, so the females would probably deem this territory (and male) unworthy.  Although this disturbance is a tragic sight, it is also a new chapter for some species. The first species I have found in the area is the Bull Thistle (Cirsium vulgare), a pink flower that is a common sight to disturbed locations. The fallen tree can also provide a new habitat for many birds. This occurred at an ideal time because May-June is the season in which birds are building new nests! Perhaps this is a blessing in disguise!

Sources:

1. Troost, K G, and D B. Booth. "Geology of Seattle and the Seattle Area, Washington."Reviews in Engineering Geology. 20 (2008): 1-36. Print.

2. Center for Urban Horticulture. Union Bay Natural Area. University of Washington, Seattle. Web. 4 June 2013.

3. Picman, Jaroslav. "Impact of Marsh Wrens on Reproductive Strategy of Red-Winged Blackbirds." Canadian Journal of Zoology. 58.3 (1980): 337-350. Print.