Black Knot Fungus

When the deciduous trees lose their leaves for the winter, the life that was slightly obscured and perhaps overlooked can become more easily seen as the landscape becomes more open.

On the left-hand side of the main trail, as it winds between the wetlands and the river, black knot fungus can be seen infecting many of the small trees of the understory.

The bumpy, black growths that grow along stems and trunks are called galls. The growth of these galls is stimulated by the release of chemicals from the fungus that makes the tree grow abnormal plant cells. After the first year, the galls appear velvety, olive green. After the second year, they reach maturity and turn knobby, rough, and black. The spores will overwinter and release the following spring.

Black knot fungus can be tolerated by many trees without negatively affecting the health of the tree. On the other hand, these fungal galls often cause damage by cracking open branches or the trunk of the tree. This makes it susceptible to wood rot fungi or other maladies.

Black knot is a fairly common disease of trees in the genus Prunus, which includes many fruits such as plums, cherries, peaches, nectarines, and apricots. There is a nonnative cherry tree that has spread throughout the arboretum. I guess that many of the infected trees I see out in the wetlands area are these cherry trees.

Hooded Merganser

I have seen a few hooded mergansers paddling around the edges of the river out at the arboretum lately.

Both males and females have a distinct, fan-shaped crest that they can raise and lower. Its hooded silhouette is a good identification clue from a distance.

The male has a white patch on the crest, a white breast with two black bars, a white wing patch, and rusty brown flanks.

The female has a gray-brown body and a brown crest. She blends in well with the surrounding earth tones of the vegetation on the river’s edge.

Their diet consists of small fish, aquatic insects, crustaceans, amphibians, vegetation, and mollusks. They have a slender, serrated bill that makes it optimal for grasping their prey.

Hooded mergansers nest in cavities of live or dead trees that are usually close to water. Therefore, it is important to have older, mature trees with sizable trunks which have either developed a natural cavity or have one excavated by a woodpecker.

Forest Gnome's Christmas Tree

As I drive around town, I see lots full of beautifully trimmed Christmas trees. There are cars with a tree tied to the top and trucks with a tree in the back. There are trees decorated with lights and shiny ornaments in the front window of homes and the front yard. It is a magical time as we come together and celebrate, and it lifts my spirits to see everyone’s decorations.

Out at the arboretum with the image of these trees fresh in my mind, I saw a clump of moss or liverwort growing on a small branch and immediately thought it looked like the shape of a Christmas tree ready for decorating.

Muskrat

Recently, I have been fortunate to observe a muskrat out in the lily pond area. It has been merrily swimming around collecting aquatic plants and eating them under the safety of a thick shelter of willow branches overhanging the water.

The “musk” part of its name comes from two musk glands found beneath the skin at the ventral base of the tail. These musk glands are used during the breeding season to mark scent posts to establish territory and to signal the male’s maturity. The “rat” part of its name is misleading. It has a naked, scaly, narrow, slightly flattened tail that is similar to a rat, but it is not a rat. That said, they are both classified as rodents.

Muskrats love water and their habitat is marshes, ponds, lakes, streams, and other wetlands.

Its body is designed for water. They have a dense coat of waterproof fur that is overlaid with coarse guard hairs. Its hind feet have specialized hairs that grow on the sides of its long toes to help propel it through the water. It has a third, clear eyelid called a nictitating membrane that protects its eyes underwater. Amazingly, it can stay underwater for up to 17 minutes! Also, to be able to gnaw on plants in the water without drowning, its incisors are outside its lips.

For housing, muskrats may either decide to dig a burrow in the bank or build a small lodge made out of plant materials, small sticks, and mud.

Nature is an inexhaustible source of wonder. Hope to see you out there.

Burt, William H. and Richard P. Grossenheider. A Field Guide to the Mammals: North America north of Mexico. 3rd ed. New York, Houghton Mifflin Company, 1976.

Rezendes, Paul. Tracking and the Art of Seeing: How to Read Animal Tracks & Sign. 2nd ed. New York, HarperCollins, 1999.

Woodland Seascapes

It’s a rainy day. Looking for a little shelter, I sit down underneath a Douglas-fir tree. Its bark is a cascade of craggy steps and cliffs. It is reminiscent of a molten past that is now cooled and solidified.

Droplets are softly falling as the rain slowly filters through the dense tree canopy. The base of the tree flares out slightly and catches the moisture. As the water flows down this gentle slope, an abundance of life is growing. Magical creatures are forming a miniature seascape that is a mosaic of shapes, colors, and textures.

Captivated by these beautiful lifeforms, I realize that it is impossible to comprehend the complexity of life woven into and around the life of a Douglas-fir tree. Its lifecycle can span more than a millennium. It can live to be from 500 to 1000 years old, and it can then take another 400 years for it to decompose. May we someday once again set aside space for these fellow beings to fulfill their lives and create majestic, hallowed forests.

Oregon Ash

Oregon Ash trees are a beautiful mess. Lounging in its shade in the summer, all seems to be in order with its full, lush canopy. As the leaves fall off and its branches are revealed, I am left wondering, “What the heck has happened to this tree?”

As this tree matures, its shape usually becomes perfectly disordered. The forces of nature love to sculpt Oregon ash trees into a magnificent structure of tangled branches, a meandering trunk, dead limbs, and numerous cavities. Thus, you don’t really see this tree being used in a planned landscape in the city or around someone’s home.

This past bird breeding season I tracked the location of many nests. Along the river path that begins at the White Oak Pavilion, the trail is lined with Oregon ash trees. Nearly every one of them has a natural cavity somewhere along its trunk, and most of them had a cavity-nesting bird using it—European starlings, northern flickers, white-breasted nuthatches, and Bewick’s wrens. In the branches of the tree, there were robins, mourning doves, cedar waxwings, and Bullock’s orioles.

Even though it doesn’t have the majestic shape of the Oregon white oak, the incense cedar, or the Douglas fir, the Oregon ash is an unsung hero.

Miniature Lampposts

While watching a chipmunk scurrying around through the leaves along the lily pond trail, something caught my eye. The sun had just come out from behind a cloud and scattered across the ground. At that moment, it illuminated these tiny globes. In some places, they appeared sprinkled across the ground. In other places, they were lined up along the edge of a leaf or blade of grass. My guess is that it is a type of fungus. Interestingly, it was growing on dead, decaying leaves, and it was growing on live, green plants too.

What is this creature? How does it fit into the web of life?

Hazelnut Leaves

Dotted across the arboretum, golden hazelnut leaves are still illuminating the fall season.

As I went in for a closer look, I immediately noticed squiggly, brown lines drawn on the leaves. A small insect has been whimsically tunneling its way through the leaves. The result is a beautiful tangle of scar tissue that stands out against the yellowing leaves.

There are vast numbers of lifeforms in nature that have the task of breaking down and recycling nutrients back into the web of life. Thank you to all the small creatures of the world for your role in helping to sustain life and making the world a beautiful, diverse place.

Black Phoebe Returns

The black phoebe has a black breast that softly fades into a white belly. The rear of the crown ends in a slight peak, and it has a slender, pointy bill.

To further help identify the black phoebe, you will see it continuously bobbing its tail up and down. Also, the one out at the arboretum regularly vocalizes. Peterson describes their voice as, “Thin, strident fi-bee, fi-bee, rising then dropping; also a sharp slurred chip.”

Their diet is almost entirely insects, and interestingly, they will occasionally catch small fish at the surface of the water. Phoebes are usually found near water like the bank of the Willamette River or the lily pond out at the arboretum where they will find a rich source of insects.

It forages from a small perch where it will quickly swoop out, snap an insect out of the air and quickly return to its spot. Its perch is usually no more than about seven feet off the ground or over the water. That said, I routinely see it sitting on top of the barn or the adjacent silo catching insects.

As you can imagine, parts of many insects are indigestible. Phoebes eat most of their insects whole and leave the chewing up to the gizzard. Naturally, there are sturdy pieces that aren’t easy to break down. These pieces build up in the gizzard where they are formed into pellets to be regurgitated. Phoebes can cough up small pellets just like owls!

Over the last 3 or 4 years, I have seen a black phoebe spending the fall and winter months at the arboretum. I wonder if it is the same individual. The map in Peterson Field Guide to Birds of Western North America shows that the Willamette Valley is the northern part of their range. A note on the map states that their range is expanding northward.

Mammoth Maple Leaves

It is hard not to marvel at the size of the bigleaf maple leaves. I often see children collecting these leaves around the arboretum. In one hand they are fanning and waving the leaf through the air while clutching a bunch of leaves in the other hand. For me, the leaves are humongous. To a child, they must be marvelously, monumentally mammoth!

So for the record and if anyone asked, I brought one home and measured it. As a side note, I broke the stem off the leaf of the first couple I collected. I also found it irresistible to wave them around through the air as I walked along the trail.

The width of the leaf was 16". The height of the leaf measured from the top to where it connects to the stalk was 11”. The leaf stalk was 12.5”.

Oregon Grape Leaf Scars

As I walked around the arboretum, I noticed that many of the Oregon grape leaves were covered with blemishes. The green leaves were like landscapes, and from my aerial view, the tan blotches appeared as burned areas. The shapes were random with red, inflamed edges. The leaves looked scorched as if a caustic liquid was splattered across their surface.

I turned a leaf over to look at the underside. Illuminated by the sunlight shining through, the paper-thin spots were changed into small, stained glass windows. This sparked an interesting shift in my perception, what I originally saw as an imperfection became a mark of beauty.

The earth is a vastly diverse and mysterious place. There are unimaginable numbers of microscopic life forms constantly creating, destroying, and transforming our world.

The Artistic Eye

I was walking down the lily pond trail, and I was struck by the patterns on a dead branch. The arrangement of shapes reminded me of the paintings of abstract expressionist Clyfford Still (1904-1980).

Art has helped me to see the world in new and interesting ways. It has aided in being able to let go of wanting to name and categorize everything. I can more fully enjoy the infinite shapes, colors, textures, and patterns in nature.

Click here to see an example of one of Still’s paintings at The Met Museum in New York.

Click here to see another example of his work on Wikiart.

Bigleaf Maple Leaves

As I head up the Zigzag Trail, I find myself shuffling through a colorful mosaic of bigleaf maple leaves. The sunlight filtering through the forest illuminates greens and golds in the canopy and myriad hues of earth tones in the decaying leaves on the ground. In addition to it being visually arresting, the sweet aroma emanating from this blanket of decomposing leaves is fairly intoxicating.

Beholding this, I decided to rest on a nearby bench to absorb the magical season of fall. As I sat there looking at all the leaves on the ground, I noticed many of the leaves had green spots that looked like a droplet of watercolor pigment had fallen on their wet, papery surface. Inside these blotches were black, raised dots which are the spore-bearing tissue of a tar spot fungus. The fungi will overwinter on the fallen leaves. With the splashing rain and wind of spring, the spores are carried back up into the tree where the life cycle begins again on new, sprouting leaves.

Interestingly, as the fungus forms on the leaves during the spring and summer, it is brown and yellow around the black dots as if it is sucking the life out of the leaf. In the fall, it seems to reverse course by creating an island of green around itself, perhaps to keep the leaf alive a little longer as it completes its life cycle.

Nature is an inexhaustible source of wonder. Hope to see you out there.

Golden-crowned Kinglet

The golden-crowned kinglet returns to the arboretum every year to spend the fall and winter months. I notice them traveling around in mixed flocks with chickadees, nuthatches, bushtits, ruby-crowned kinglets, and brown creepers.

The males have a yellow-orange crown patch and the females only have a yellow stripe. During the breeding season, the male will flare his orange patch when chasing off male intruders in his territory.

In my experience, the male’s orange patch appears fairly subtle. Occasionally I see one slightly flare it as he seems to be chasing another male. Since it isn’t breeding season, maybe he is just practicing for when the real moment arrives. This “territorial” urge seems to pass fairly quickly, and they soon return to merrily flitting through the canopy, foraging together and whistling their sweet little calls.

This bird quickly zips and zings around in all directions through the landscape. Thus, it isn’t the easiest bird to follow, observe or attempt to capture in a photo. I am grateful to have it here as a seasonal resident, and I’ll keep watching and learning.

Oregon Junco Camouflage

With all the newly fallen leaves, the earth-tone colorations of the Oregon junco blend in well with the surroundings. Even as they hop, skip, and jump around in the leaves foraging for food, it is easy to flush them off the ground if you aren’t moving slowly and paying attention. They are also well camouflaged as they explore the branches in the tree canopy.

They stay in constant contact with each other as they move through the landscape. Their communication sounds are subdued, so you must keep a fairly sharp ear out. Peterson describes their vocalization call as “a light smack.” They also have “clicking or twittering notes.”

Robin Eating Madrone Berries

Yesterday I could hear robins making clucking noises in the upper part of the parking lot, and I went to investigate. They were chasing each other around the tree tops and calling to each other. I’m not sure what all the excitement was about, but I did see robins occasionally visiting the madrone tree to eat a berry. I was expecting them to start gobbling them up like they did with the dogwood berries, but they didn’t. They seemed to be testing them out to see if they were ripe enough for their taste. After about 15 minutes the robins moved on, but I have a feeling they will be back.

I am only hearing and seeing robins up in the trees around the arboretum. I haven’t noticed them foraging on the ground for a few weeks. With all of the recent rains, I am sure there are lots of yummy worms to be found underneath the newly fallen leaves. Most animals vary their diet. As the seasons change, food sources become more or less available or unobtainable. I’m sure the robins know what is best to eat to have a well-rounded, nutritious diet.

Barred Owl

The other evening I watched a barred owl zigzagging down the creek trail corridor hunting for food. It would sit on a perch about 10-20 feet off the ground and scan the area with its eyes and ears. When it zeroed in on its potential prey, it silently drifted out over the meadow and pounced.

Barred owls prey on a variety of animals. On the National Audubon Society website they list their diet as: “Mostly small mammals. Eats many mice and other small rodents, also squirrels (including flying squirrels), rabbits, opossums, shrews, other small mammals. Also eats various birds, frogs, salamanders, snakes, lizards, some insects. May take aquatic creatures such as crayfish, crabs, fish.”

The barred owl is an elegant, magical creature with a distinctive hooting rhythm that is interpreted as, “Who cooks for you? Who cooks for you-all?” Click here to listen on the All About Birds website by The Cornell Lab.

Their original range was the mature forests of the eastern North America. During the past century they expanded westward across Canada and down into the Northwest and California of the U.S.

The expansion of its range has brought it into contact with the spotted owl of the West, because they share a habitat of older growth forests. As a result barred owls have been displacing or occasionally hybridizing with spotted owls. This interaction, along with loss of habitat, increased the decline of the spotted owl’s population. I won’t expand on this story here, but I recommend researching more about it.

Nature is an inexhaustible source of wonder. Hope to see you out there.

The Creek is Flowing

Welcome back little creek.

The creek has been flowing up the canyon since last week, and it has finally reached the small spillway as you cross the bridge into the White Oak Pavilion.

It is nice to listen to its song as I enter the arboretum and see all of the newly fallen leaves floating in it.

Rain Catcher

Spiders are amazing.

Pacific Ninebark Pithy Stems

Along the lily pond trail, the caretakers of the arboretum have trimmed back branches that grow into the pathway. I noticed that pretty much all the cut branches of the Pacific ninebark have small round holes in the center of the branch. I found a broken branch that showed a pithy center that I am sure is easy and delightful to bore out. As I looked further, I noticed that there were also holes in the cut branches of the snowberry bush and the Indian-plum.

I was reminded about something that I learned from the Xerces society. It is important to leave old flower stalks in your garden landscape. Many insects and spiders will seek refuge in the stalk’s hollow stem. They will also lay their eggs in the stems for protection through winter and hatch out in spring.

I also noticed that along some of the branches there were holes that I imagine were created by woodpeckers extracting whatever tasty morsels were inside.