This agile, little bird swiftly tumbles through the underbrush as it merrily searches for food. It ducks under fallen trees, disappears into thickets of sword fern fronds, and heroically bounds out onto a stump as it reappears.
It’s no surprise that its song is an energetic, warbling arrangement of notes that mimics its acrobatic movements.
Pacific Wren
The last post showed the vibrant green growth of new leaves as spring unfolds. On the other hand, within this same landscape, some plants’ new leaves begin as red—poison oak, Oregon white oak, and Oregon grape.
Check out this article I found online from Henderson State University:
Green Leaves Often Start and End as Red Leaves
The green coloration in the leaves of most plants is due to the presence of chlorophyll, a pigment used to absorb energy from the sun. Wavelengths of light from the visible spectrum (sometimes seen on rainy days as a "rainbow") are absorbed by the chlorophyll, with the exception of the green wavelengths, which are reflected. Young and old leaves very often are red, however. It is curious as to why some leaves begin development with red coloration, become green after they are largely grown, then return to red as they die.
The delayed greening has been studied as an adaptive strategy for the plant. One line of thought is that the young leaves are not yet performing photosynthesis, so they are not capturing energy from the sun and making food, therefore they are without much nutritive value to the plant. There also is little nutritive value to an herbivore. The plant is investing energy to grow the new leaf, so avoidance of herbivory allows the investment a better chance to mature. If being red decreases the risk that the new growth will be eaten by herbivorous animals, then the plant has used a successful strategy. Those species that delay greening have reddish leaves due to a chemical known as anthocyanin. This chemical appears reddish under more acid conditions and more bluish under basic conditions. Because most tissues are acid, the red color typically shows.
The optical properties of the anthocyanins have been studied most recently. Most invertebrate herbivores, such as insects, can detect colors in the blue range but not in the red range of the spectrum. Also, most mammals, with the exception of primates, essentially are blind to color in the yellow to red range, so perceive those colors as shades of gray. Red leaves would be perceived by leaf predators as somewhat dark and maybe dead, and therefore not a choice food material. Perhaps the red of new leaves, then, allows the plant to hide them by making them cryptic or unattractive to the herbivores that would otherwise eat them as they grow.
When the growing season is over, leaves become red or yellow as the chlorophyll begins to disappear due to shorter days and cooler weather. Red in dying leaves is due to the same pigment--anthocyanin--that made the young leaves red, but yellow coloration is caused by carotene. These fall colors can be therapeutic to humans due to the relaxing effect of the colors. However, the colors already were present; they were just hidden by the green chlorophyll for most of the year. Thus, as leaves of some deciduous plants begin to shed, they may return to the red color they had at the beginning of their life.
Link to website article:
Green Leaves Often Start and End as Red Leaves
Poison Oak
Oregon White Oak
Oregon Grape
A myriad of patterns burst forth in spring as all of the vibrant, new leaves emerge. Each plant forms a beautiful mosaic of shapes, sizes, and green colors.
The world feels fresh. My mind feels more open.
The western gray squirrel is a marvelous creature. Its defining feature is an amazingly bushy tail that is nearly as long as its body. It has a beautiful coat of gray fur frosted with silver-white tips. Its underside and the crescents that bracket its eyes are white.
Look for this animal acrobatically moving through the trees or hopping around on the ground as it forages for food. A staple part of its diet at the arboretum is acorns. When the nuts are ripe, it will bury them in the ground or use a tree cavity to cache them. In June, I’ll see it whittle down the oak galls, presumably to eat the insect larvae inside. In early August, I’ll see it eating the inner bark of big leaf maples—under the tree will be small pieces of bark etched with teeth marks. I also see it eating Douglas-fir seeds and fungi.
For nesting, it uses tree cavities or builds a nest of sticks and leaves. It bears a single litter each year between late February and May.
It is a fairly shy animal and is rarely vocal. It is very aware of its surroundings, so I have to move slowly or be still to observe it. If it feels uncertain or afraid, it will scurry up into the tree canopy or bound away along the forest floor.
References
Mathews, Daniel. Cascade-Olympic Natural History. Raven Editions in conjunction with Portland Audubon Society, 1988.
Moskowitz, David. Wildlife of the Pacific Northwest: Tracking and Identifying Mammals, Birds, Reptiles, Amphibians, and Invertebrates. Timber Press, 2010.
The male Douglas fir cones have opened up this week. The pollen can be seen flying through the air and coating the newly forming female cones at the end of the branch.
In some neighborhoods, the pollen can be seen swirling in the streets and coating parked cars. I have seen many people struggling with stuffy noses and watery eyes. Hopefully, the rain coming tomorrow night will help settle the dust and gives some folks a little relief.
I have been trying to stay tuned in to the whereabouts of the pileated woodpecker pair that I posted about earlier this month. Ten days ago, I found the male making a substantial hole in a dead Douglas Fir. I wasn’t sure if he was searching for food or building a nesting cavity. I have returned there a couple of times to find him continuing to excavate the hole, so I feel that he is building a cavity for nesting. The last time I went by, he could get the top of his body inside the hole. Both the male and female excavate the cavity, but the male does more. The depth of the cavity can range from 10 to 24 inches, and it is 15 to 80 feet from the ground. It takes from 3 to 6 weeks to complete.
It is exciting to see a pair of them living and breeding at the arboretum.
The arboretum has perfect habitats for owls. There is an old barn with a silo for Barns Owls. There are old-growth cottonwoods along the river for Great Horned Owls. There are cavities in Oregon Ashes for Western Screech Owls and Northern Pygmy-Owls. There is a forested hillside with a mix of large Douglas firs, big-leaf maples, and incense cedars that attracted a Barred Owl this winter. Within all of the habitats, there are transition zones and open meadows that support an abundance of prey for owls—voles, mice, small birds, etc.
Owls will often spend consecutive days around the same perch from where they will roost during the day and hunt at night Most owls are nocturnal, but Northern Pygmy-Owls mostly hunt by day. Under these roosts, you can often find evidence of an owl’s presence: owl pellets.
Owls usually eat their prey whole or in large pieces. The fur, teeth, bones, or feathers of animals are indigestible. These parts are formed into an oval mass, passed back up the digestive system, and regurgitated some hours later, often while the owl is roosting. These pellets are a joy to find. On the outside, most owl pellets aren’t very remarkable. They are usually furry, matted orbs of hair. On the inside, they are a treasure of interesting bones, teeth, and skulls! Online there are illustrated charts that help identify all of the contents.
If you find it hard to locate an owl pellet, they are for sale. On the internet, I found a place in Baker City called Oregon Owl Pellets that sold large pellets for $3 apiece.
Nature is an inexhaustible source of wonder. Hope to see you out there.
I found these lichens growing on a fallen incense cedar tree. When I look up close at this miniature environment, I am fascinated by how much terrestrial life reminds me of the sea. This lichen's structure and vibrant colors look like a coral reef. It is easy to imagine small fish, eels, and other creatures darting in and out.
Lichens are such a mysterious life form. They are a symbiotic union between an alga and a lichen. They grow in a myriad of beautiful shapes, sizes, and colors. As you walk around the arboretum, look for them hanging from branches, wrapped around limbs, and encrusting tree trunks. You can also find them clinging to the surface of rocks. They live in a diverse range of habitats from the desert to the alpine tundra. There are approximately 3600 species in North America!
The sun was shining Thursday, and it nicely warmed the day. It felt like spring had arrived.
I watched a female robin building her nest. She was collecting mud, grass, lichen, and other plant material. It was fun watching her build it. Sometimes she would land above the nest, drop the material into it, and then hop down to arrange it in the nest. As I watched her, she seemed free-spirited and joyful. She took a break every so often to forage and check in with her mate. He was always nearby watching and ready to chase off any intruders.
While looking in the small pools in the parking lot for frog eggs, I found a caddis fly larva. It was waddling around the pool searching for algae and other organic debris to eat. It makes the most beautiful, mobile home in the larval stage.
Depending on the environment, the larva gathers plant material, leaves, twigs, sand, small rock fragments, or other detritus, to build its temporary home. It cements it together with salivary silk forming a cylindrical tube. It lives inside this camouflaged, protective casing as it develops. When it is fully grown, it closes the tube ends and pupates inside. After this stage, it will cut open the case, rise to the surface of the water, undergo a final molt, and begin flying. As an adult, it usually only lives for a few weeks. During this time it focuses on reproduction. Most species do not eat as an adult, but a few species will visit flowers for nectar.
I have a photo of the adult somewhere in my album. When I find it, I will post it.
There are small, shallow pools in the lower parking lot. The Pacific tree frogs love to lay their eggs in the sunny, warm puddles. It is the perfect nursery. Algae grow in the pools for the tadpoles to eat, and they have places to seek shelter under leaves and other vegetation.
If you are lucky, you might see one of the tree frogs in or around the water. It is a small frog measuring from ¾ to 2 inches. It varies in color from green to light tan and has a distinctive black or dark brown stripe through the eye. It also has notable, large toe pads.
Frogs are very susceptible to pollution. So it is interesting to see them successfully using these pools in the parking lot. The runoff of grease, oil, etc., must be minimal at this end of the lot.
I’d like to give a friendly public service announcement. Please remember to keep dogs out of these pools and the seeps along the quarry road. Along with frogs, they are filled with many fragile creatures.
Standing at the top of the zigzag trail, I could hear hammering resounding through the forest. I walked down the path to find a pair of Pileated Woodpeckers on a dead tree. They were excavating small holes in the wood using their chisel-like bills as they searched for food.
They will make holes in trees to get to the tunnels of carpenter ants or wood-boring beetles and termites. The holes are often in a rectangle shape and can be quite deep—a good sign that a Pileated Woodpecker is in the area. You will see these characteristic holes on the older Douglas Fir trees near the juncture of the zigzag and hillside trails.
When a Pileated Woodpecker discovers an insect path inside the tree, it has an incredible tool to procure its food. Its tongue is part of a fascinating system of small bones and muscles that wrap around the back and top of the skull to its forehead. In What It’s Like to Be a Bird, David Sibley writes, “The long tongue has a barbed and sticky tip, and tiny muscles that allow the bird to bend the tip of the tongue in any direction, so it can follow twisting tunnels, trap prey against walls, and pry insects and larvae out of their hiding places deep inside a tree.” That is truly amazing!
In addition to the sound of pounding on trees, you can also hear the vocalizations of the Pileated Woodpecker reverberating across the landscape. Click here to listen to their calls on Cornell’s website All About Birds.
Once its sound has clued you into its whereabouts, you will be in for a real marvel. Assuming that the Ivory-billed Woodpecker is extinct, the Pileated is the largest woodpecker in North America. Both the male and female have flaming, red crests. The red on the male includes the forecrown, and he has a red mustache mark. Good luck in finding this spectacular bird!
Nature is an inexhaustible source of wonder. Hope to see you out there.
Out in the wetlands, northwestern salamanders have been laying their eggs. The eggs are encased in a gelatinous mass that is roughly the size of a small grapefruit. They are attached underwater to small branches, grass, or other aquatic plants.
The eggs hatch in 2 to 9 weeks. During that time, algae will start to grow inside mass which provides them with oxygen. When the larvae hatch from eggs they swim using a tail fin and breathe with filamentous, external gills. When the larvae mature, they usually transform into salamanders that live on land. That said, Northwestern salamanders can develop into neotenic adults. This means that they stay in the water throughout their lives and retain their gills and finned tails. This phenomenon is seen more in higher altitudes.
The terrestrial adults spend much of their lives in moist places underground. They stay in and under rotten logs and often utilize the tunnels of burrowing mammals such as moles. This is probably why I don’t see them. I have only seen one out in the wetlands, and it was being eaten by a red-spotted garter snake.
There are bullfrogs out in the wetlands, and I was worried they might eat the salamanders. I was relieved to read that the larvae and terrestrial adults are mildly poisonous, so they can generally survive alongside predatory species, such as bullfrogs. Hopefully, the eggs will be safe. Perhaps they hatch out before bullfrogs are very active.
Indian Plums are dioecious plants, which means the male and female flowers are on different plants.
I went out over the weekend to photograph the flowers to show you. The top two photos below are male. You can see the stamens loaded with yellow pollen. The bottom two photos below are female. They have 5 pistils in the center. Interestingly, it looks like small stamens surrounding the pistils that appear to be not viable.
Another interesting characteristic about these flowers is their fragrance. The scent is described as something between watermelon rind and cat urine. There is something more to be said about that peculiarity, but I’m not sure what at the moment. It requires more research. If you have a chance to smell them, let me know what you think.
The Birder’s Handbook: A Field Guide to the Natural History of North American Birds is a great resource. It has information on the biology of bird species “known to nest regularly on the continent, north of the Mexican border (with the exception of some exotic species that have escaped from captivity) and all the now-extinct birds known to have nested here since the arrival of Europeans.” The book is also full of essays covering different biological topics. Here is an excerpt from the essay “Bathing and Dusting:”
“…Feathers are marvelous and intricate devices, but keeping them functional requires constant care.
A bird is considered to be bathing whenever it uses any of several stereotyped movements to wet its feathers. One pattern, wading, is commonly observed in birds with strong feet and broad, short, flexible wings. In a typical sequence a bird stands in the water, fluffs the feathers to expose the bare skin between their bases, and rapidly flicks the wings in and out of the water. The breast is submerged and rolled vigorously back and forth, and then, as the front end emerges, the head is thrown back, forming a cup with the partially elevated wings and tail, and dousing the feathers of the back. Those feathers are elevated so that the water reaches the skin, and then lowered, forcing the water between them. The sequence may be repeated, with the bird submerging farther in each cycle, until it is a mass of soaked, disarranged feathers.
…Songbirds shake themselves to throw off water by vibrating wings and tail and ruffling feathers. All birds normally follow bathing with preening.”
The water in the creek is lightly flowing at the moment due to the lack of rain over the past couple of weeks. There are plenty of stretches where the water is shallow. The depth is perfect for songbirds to wade out into the creek and take a bath. I love watching them splash around in the water.
Remember to click on the photos to enlarge and scroll through them.
The hermit thrush blends well into the winter landscape. Its head and back are medium-brown and are accented by a warm, rufous tail. Its breast is patterned with brown spots that appear slightly smudged.
To further help in identifying this bird, look for behavioral clues. It will occasionally cock its tail, slowly lower it, and slightly flick its wings. When foraging, sometimes it will pick up leaf litter with its bill or shake the grass with its feet. Its diet consists mainly of insects such as beetles, caterpillars, bees, ants, wasps, and flies.
Recently, I walked up the creek trail, and I saw one perched in a tree patiently observing its surroundings. Eventually, it flew to the ground and started foraging along the edge of the path. It picked through the leaves, uncovered a few juicy worms, and gobbled them up.
At the arboretum, I only see the hermit thrush in the winter. It is a short-distance migrant that breeds throughout North America (click here for a range map). So if you miss seeing it at Mt. Pisgah this winter, there is a good chance that you can see one nearby on an adventure this summer.
I wish you luck in finding this beautiful bird. I also hope that you have the opportunity sometime to hear its peaceful, sylvan song. Click here to listen.
To identify birds successfully, many aspects are helpful to be in your awareness. In the front of Peterson’s Field Guide to Birds of Western North America 4th Edition, there is a section of excellent questions to consider with illustrations. For example, “What is its shape?” Peterson has two illustrations side by side and asks, “Is it plump like a starling (left) or slender like a cuckoo (right)?”
To cap off the end of the book, Peterson included three panels of illustrations of the silhouettes of birds—shore, flight, and roadside. This is an important reference when determining what bird you’re watching because the lighting isn’t always ideal. Can you guess the ones in the photos?
When it came to identifying birds in the field, Roger Tory Peterson was an expert and created an invaluable guide to help us learn and enjoy our time birding. Thank you for all of your hard work and dedication!
Nothing Gold Can Stay
by Robert Frost
Nature’s first green is gold,
Her hardest hue to hold.
Her early leaf’s a flower;
But only so an hour.
Then leaf subsides to leaf.
So Eden sank to grief,
So dawn goes down to day.
Nothing gold can stay.
————————————————
The Indian plum is a small, airy shrub that is one of the first plants to bloom as winter comes to a close. On the ends of its curving branches, new leaves are sprouting. The sunlight shining through them is creating luminescent, green flames. The shrubs are becoming brilliant candelabrums to light the pathway to spring.
The forecast for this Tuesday is a nighttime temperature of 16 degrees! Hopefully, our first green will stay.
When David Douglas visited Oregon in 1826, he noted that the low hills of western Oregon were covered by Oregon White oaks and grass. This oak savanna land was formed through fires set by native people and lightning. The mature oaks were able to resist these mostly low-intensity fires that cleared the ground vegetation.
As a result of fire suppression, coniferous forests have closed up these open landscapes. Because the Oregon white oak is intolerant of shade, the oak savanna habitat has declined. That said, small remnants of this landscape can still be seen out at the arboretum and throughout the Willamette Valley.
In the forest above the White Oak Pavilion, there is an example of this phenomenon. An old, dead oak tree can be seen in the shadows of towering Douglas fir and incense cedar trees that have taken over the hillside.
Underneath a thick carpet of moss was a trunk. Its lid was etched with a mosaic of primordial soup. I looked over the gaseous, wooden shroud carefully. As I sat wondering what was inside this mysterious vessel, a wind blew through and swept all thought from the corridors of my mind. At that moment, I found myself able to step inside. Upon entering, I could see the radiating concentric rings of time. I saw innumerable ripples interlacing into one another. Creating one fabric into which all life was woven.
