Orange-crowned Warbler

This little songbird is olive green with yellow undertail coverts and slight streaking on the breast that looks blurry. They have sharp pointy bills and a thin white or yellow stripe over the eye. There is an orange crown on the head that is seldom seen unless the feathers are raised when the bird is excited or agitated. This bird must have a peaceful spirit. I browsed photos online and didn’t come across any photos of the crown raised. Also, I imagine the orange is fairly subdued and not as bright as a ruby-crowned kinglet, for example.

If you want to see one at the arboretum, look along the river bank. I am seeing them foraging in the willows and osoberries. Their diet consists mainly of invertebrate prey, including ants, beetles, spiders, flies, and caterpillars.

On All About Birds Most it says, “Orange-crowned Warblers nest on the ground, possibly to avoid nest-robbing birds. One exception is the sordida or ‘dusky’ subspecies that breeds on California’s Channel Islands.” I thought this was interesting because I didn’t imagine a warbler that I see flitting through trees and shrubs as nesting on the ground. In Peterson Field Guide to North American Bird Nests it says, “Nest and placement are similar to those of other ground-nesting wood warblers; frequently on shaded woody slopes, hillsides, canyons, or steep banks.”

Peterson describes their voice as: “Song a colorless trill, becoming weaker toward end. Often changes pitch, rising or dropping slightly. Call a sharp stik.” Click here to listen on All About Birds. When you go to listen, you’ll notice that Orange-crowned Warblers are divided into four subspecies. “The one named celata is found in Alaska and across Canada, and it is the dullest and grayest. The Pacific Coast form, lutescens, is the brightest yellow. Found throughout the Rocky Mountains and Great Basin, orestera is intermediate in appearance. The form sordida is the darkest green and is found only on the Channel Islands and locally along the coast of southern California and northern Baja California (All About Birds).”

Resources
McFarland, Casey, et al. Peterson Field Guide to North American Bird Nests. Houghton Mifflin Harcourt, 2021.

Orange-Crowned Warbler Life History, All About Birds, Cornell Lab of Ornithology. https://www.allaboutbirds.org/guide/Orange-crowned_Warbler/lifehistory. Accessed 15 Apr. 2023.

Orange-Crowned Warbler Overview, All About Birds, Cornell Lab of Ornithology. https://www.allaboutbirds.org/guide/Orange-crowned_Warbler/overview. Accessed 15 Apr. 2023.

Peterson, Roger Tory, et al. Peterson Field Guide to Birds of Western North America. 4th ed, Houghton Mifflin Harcourt, 2010.

Chickadees Foraging

To me, chickadees are very aware, curious, and smart birds. Watching them will clue you into many interesting things in nature.

At the moment as the osoberry leaves are continuing to emerge, some of the leaves aren’t unfolding. Some of the leaves are growing and staying tightly wrapped together. Inside this envelope of leaves, there are tiny, white larvae. Somehow, the eggs of this insect have caused the shrub to create this casing of leaves which also has a noticeable fuzziness too.

Chickadees love opening these little packages and they hang and cling to them in all sorts of acrobatic ways. Sometimes the leaf wraps will pop off and the chickadees will carry them over to a branch. Either way, within 10 to 15 seconds, they are able to open them up and extract the larvae.

I have put mesh produce bags around some of the branches to see if I can capture some of these insects as they mature into adults. Since the larvae are all so small, my thinking is that they will develop to maturity fairly quickly. I am hoping that within the next week or so I will see an insect flying around inside the bag.

Squirrels

Tree squirrels are amazing acrobats. They fearlessly climb out onto the tips of branches to reach seeds or take fearless leaps between limbs. They chase each other up, down, and all around the trunk of trees with speed and agility. Their lives seem to involve a great amount of risk or chance.

Not to worry, squirrels have the body mechanics and dexterity to live a life in the trees. To hold on to the tree, they have sharp, curved claws that help them grip the bark. To climb and leap between branches, they have powerful muscles in their hind legs. They are noticeably bulging in the photo as it supports its body facing down the tree. This brings me to what inspired me to write this post. To be able to descend head first down a tree, a squirrel’s back ankles can rotate a full 180 degrees! In the photo, you can see them swiveled back as it hangs on the tree.

It is safe to say that they are at home up in the trees and have a great ability in navigating their world. They have immense knowledge of the forest in how the branches grow and weave together. They must create intricate mental maps of the canopy which is a complex maze of roads leading to food, safety, and shelter. Squirrels are such fascinating creatures to wonder about and observe.

Nature is an inexhaustible source of wonder. I look forward to seeing you out there.

Resources
Brookshire, Bethany. “Do the Twist, The Science behind Death-Defying Acrobatics of the Average Squirrel.” Sierra, no. Spring, 2023, pp. 54–55.

California Scrub-Jay

The California Scrub-Jay is a magnificent bird that is a year-round resident out at the arboretum.

The upper part of the bird is blue and gray which is contrasted by pale, whitish feathers on its underside. The blue extends off the back of the head and neck onto the sides of the breast creating a scarf or necklace that accentuates its white throat. It has a thin, white eyebrow stripe that sits above a dusky gray that surrounds the eye. The plumage is the same for both sexes.

It is a sizable bird at 11 inches in length which is slightly larger than the American Robin and smaller than the American Crow. As it perches on treetops surveying its surroundings, its long tail becomes apparent.

Its bill is straight and stout, with a hook at the tip that comes in handy for gripping the smooth shell of a nut. I recently watched it collect a cached hazelnut and fly off to eat it.

The California Scrub-Jay likes open habitats, oak woodlands, and chaparral areas. Out at the arboretum, I often see it around the parking lot, the upper part of the creek trail, and the edges of the south meadow.

This bird can be very vocal and is a familiar and recognizable sound to most people. Its voice seems to carry across the landscape as it moves through the treetops defending its territory, warning of predators, expressing the love of its life and home at the arboretum, etc. Peterson describes its voice as: “Rough, rasping kwesh…kwesh. Also a harsh shreck-shreck-shreck-shreck and a rasping zhreek, zhreek.” In contrast to these cacophonous sounds, during courtship or when the pair is close together they sing “a soft medley of sweet notes that can last up to 5 minutes (All About Birds).” Click here to go to All About Birds to listen.

Nature is an inexhaustible source of wonder. I look forward to seeing you out there. Happy Spring!

Resources
California Scrub-Jay Overview, All About Birds, Cornell Lab of Ornithology. https://www.allaboutbirds.org/guide/California_Scrub-Jay/overview. Accessed 29 Mar. 2023.

Curry, Robert L., et al. “California Scrub-Jay (Aphelocoma Californica), Version 1.0.” Birds of the World, 2020. birdsoftheworld.org, https://doi.org/10.2173/bow.cowscj1.01.

Peterson, Roger Tory, et al. Peterson Field Guide to Birds of Western North America. 4th ed, Houghton Mifflin Harcourt, 2010.

Swirling Wood

I found this gnarled old knot on the ground. I was fascinated by its liquid form in contrast to the solidity of its woody mass. The infinite amount of shapes in nature is truly unbelievable. It takes so much time to experience and explore nature that sometimes it feels that our lives are so unjustifiably short considering the endless wonders in the world, even in our own backyards.

Pacific Tree Frog

Pacific tree frogs will even seek these small, shallow pools of water in the parking lot to mate and lay their eggs. For such a small creature, they have powerful vocalizations that are amplified by passing air into the frog's vocal sacs. These sacs expand from the floor of the mouth to create a chamber that enhances/resounds their mating call.

I want to expand this breeding area by blocking off the end of the parking area. The frogs like this area because it is fed by a small flow of rainwater that slowly seeps into the ditch. One of the biggest challenges that humans face is setting aside habitats for nature for it to live and thrive. It is paramount for our own survival.

Wrentit

The wrentit is part of an Old World family known as Babblers (Family Timaliidae), and it is the only species of this family in North America. It is a plain, brownish-gray bird with a long, rounded tail that is often cocked. It has a short, slightly curved bill and a lightly streaked breast. Males and females, as well as adults and juveniles, look alike.

It prefers to stay hidden in the cover of shrubs and thickets, so it is more often heard than seen. Here is the description of their song by All About Birds: “Wrentits sing a distinctive song reminiscent of a ball bouncing that lasts for about 4 seconds. In males this starts out as 3 to 5 pits followed by an accelerating trill; the ball bounces away. Females also sing but they catch the ball and sing only 3 to 14 pits without the accelerating trill. Both sexes sing at all hours of the day, all year long, although they are more vocal within the first hour after sunrise and early in the breeding season.” Click here to listen on All About Birds.

Breeding season is here, and many birds are beginning to establish territory and trying to attract a partner, both of which Wrentits most likely have already accomplished.

First, “Wrentits may pair up as early as 30 to 40 days old, and they stay with that mate for the rest of their life (All About Birds).”

Second, once a pair establishes a territory, they defend it year-round and rarely leave. In fact, “Wrentits are homebodies and may be the most sedentary bird species in North America. They rarely travel more than 1,300 feet from where they were born (All About Birds).” The pair I see are usually roaming around the wetlands or on the adjacent hillside in the vicinity of the incense cedar exhibit.

Nature is an inexhaustible source of wonder. I look forward to seeing you out there.

Resources
Ehrlich, Paul R., et al. The Birder’s Handbook: A Field Guide to the Natural History of North American Birds: Including All Species That Regularly Breed North of Mexico. Simon & Schuster, 1988.

Peterson, Roger Tory, et al. Peterson Field Guide to Birds of Western North America. 4th ed, Houghton Mifflin Harcourt, 2010.

Sibley, David, et al. The Sibley Guide to Bird Life & Behavior. 1st ed, Alfred A. Knopf, 2001.

Wrentit Overview, All About Birds, Cornell Lab of Ornithology. https://www.allaboutbirds.org/guide/Wrentit/overview. Accessed 15 Mar. 2023.

Foliar Marcescence

In autumn, deciduous trees will shed their leaves. This process is known as leaf abscission. Curiously, out at the arboretum, there are a few oak trees that still have the copper-brown leaves from last autumn. Why aren’t the leaves falling off the tree?

The process of holding onto to the leaves through the winter is known as foliar marcescence. From what I have read, this phenomenon is seen in trees like oaks, American beech, hornbeams, and witchhazels.

How this happens is understood—the leaf hasn’t formed an abscission layer at the base of the leaf petiole allowing the leaf detach. Why this happens is a bit of a mystery. The leading theory is that the dead leaves are not palatable or nutritious so they protect the leaf buds from browsing mammals, like the black-tailed deer that live at the arboretum. In addition, rummaging around dry, noisy leaves could potentially alert nearby predators. Another theory is that delaying the leaf drop until spring provides a fresh layer of leaf mulch around the base of the tree.

Leaf marcescence is usually seen on small, younger trees or on the bottom limbs of mature trees. I found examples of both occurrences at the arboretum. Another interesting part of this story, which I have yet to read about, is that I saw leaves on the tree that were older than last year. There were layers of gray, decaying leaves on the limbs, and some had a substantial amount of lichen growing on them. Those have to be leaves from at least the year before last.

There are so many mysteries in the world, even in our own backyards.

Resources
Feb 13, 2019 | Print. “Winter Leaf Marcescence.” Home & Garden Information Center | Clemson University, South Carolina, https://hgic.clemson.edu/winter-leaf-marcescence/. Accessed 11 Mar. 2023.

“The Mystery of Marcescence.” Tennessee State Parks, https://tnstateparks.com/blog/the-mystery-of-marcescence. Accessed 11 Mar. 2023.

Downy Woodpecker Continued

The Downy Woodpecker is a delightful little bird that can be seen throughout the year at the arboretum. It is black and white with white spots on the wings, a white stripe down the center of the back, and a striped head. It also has spots on the outer tail feathers. The sexes are easily distinguished by the vivid red patch on the back of the male’s head, which is absent on the female.

As I stated in my previous post, in the fall and early winter, the males and females lead more independent lives. This is all about to change as winter draws to a close and they start pairing up for mating. The first sign of this is when both sexes begin drumming by striking their bills against resonant parts of trees—hollow trunks, dried branches, or planks created where a tree has broken during a storm. These rhythmical sounds ringing across the landscape function to establish territory and to attract mates, as many birds accomplish through vocalizing a song. I expect them to start drumming soon.

I followed a pair of downy woodpeckers around for a few weeks when they were drumming last year. I realized that there were many damaged trees due to storms because they were popular drumming posts. I also became more aware of the amount of snags peppered throughout the landscape because they were also popular drumming posts and places to forage. Does part of a healthy ecosystem include damaged trees from storms? I think the woodpeckers would say yes.

Resources
Downy Woodpecker Overview, All About Birds, Cornell Lab of Ornithology. https://www.allaboutbirds.org/guide/Downy_Woodpecker/overview. Accessed 2 Mar. 2023.

Ehrlich, Paul R., et al. The Birder’s Handbook: A Field Guide to the Natural History of North American Birds: Including All Species That Regularly Breed North of Mexico. Simon & Schuster, 1988.

Peterson, Roger Tory, et al. Peterson Field Guide to Birds of Western North America. 4th ed, Houghton Mifflin Harcourt, 2010.

Stokes, Donald W., et al. A Guide to Bird Behavior. 1st ed, vol. II, Little, Brown, 1983.

Downy Woodpecker Foraging

I love Downy Woodpeckers. I watched this one yesterday and wanted to write a little about them. I looked back in my blog posts and saw that I wrote about the Downy Woodpecker on Feb. 18, 2021. I have noticed that I often observe and take photos of the same birds at the same time each year.

I found this interesting observation on All About Birds by The Cornell Lab: “Male and female Downy Woodpeckers divide up where they look for food in winter. Males feed more on small branches and weed stems, and females feed on larger branches and trunks. Males keep females from foraging in the more productive spots. When researchers have removed males from a woodlot, females have responded by feeding along smaller branches.”

I love the last photo that shows the Downy twisting its neck to presumably be able to better extract an insect larvae.

European Starling Cleaning Cavity

Male starlings begin building the nest before mating takes place. They choose the nest site and use it to attract females. Yesterday I saw a European Starling cleaning out a nest cavity which has been used by Starlings for at least the past 5 years.

What originally drew my attention to this Starling was all of the interesting sounds it was creating. After making a couple of trips taking debris out of the nest cavity, it would perch on a branch next to the hole and vocalize an array of whistles, warbles, chatters, and bird mimicry. Individuals can learn the calls of up to 20 different species, such as, the Eastern Wood-Pewee, Killdeer, meadowlarks, Northern Bobwhite, Wood Thrush, Red-tailed Hawk, American Robin, Northern Flicker, and many others. This Starling was occasionally throwing in the sound of a Red-winged blackbird.

Starlings are beautiful birds. In winter, their plumage is brown, covered in white spots. In summer, they have a purplish-green iridescent (which I see a little appearing in the photo) with yellow beaks. All About Birds had this cool fact: “Starlings turn from spotted and white to glossy and dark each year without shedding their feathers. The new feathers they grow in fall have bold white tips – that’s what gives them their spots. By spring, these tips have worn away, and the rest of the feather is dark and iridescent brown. It’s an unusual changing act that scientists term ‘wear molt.’”

See you out there!

Common Merganser

Lately, two males and one female common mergansers have been swimming around on the river at Mt. Pisgah. They are sizable birds at 24-25 inches in length. The male has a long, whitish body with a breast tinged a rosy peach. It has a black back and green-black head. Its bill and feet are red. The female and immature have a gray body with a crested, rufous head that contrasts with a white chin and chest.

Common Mergansers spend the breeding season in northern forested habitats near large lakes and rivers. They are year-round along the Willamette river and are frequently seen at the arboretum. They usually nest within a mile of water in natural cavities or ones made by woodpeckers. So, forests along the river must be preserved in order to mature into trees large enough to allow for a suitable nesting cavity.

Common Mergansers have 1 brood, a clutch size of 6-17 eggs, and an incubation period of 28-35 days. After Common Mergansers are born, the leave nest cavity after a day or two. Even though they are flightless, they fearlessly leap out of the nest cavity (which can be up to 100 feet off the ground), land on the forest floor, and head for the water. From the beginning, they are able to catch all of their own food and start by diving for aquatic insects. Amazingly, they switch over to catching fish at about 12 days old. These bold and independent chicks are still small and vulnerable and will stick close to their mom for protection.

The Common Merganser’s diet consists mostly of fish, and their bills have sharp serrations for grasping this slippery prey. They also eat aquatic invertebrates (including insects, mollusks, crustaceans, and worms), frogs, small mammals, birds, and plants.

They are found throughout a large part of North America. Check out the range map on All About Birds by The Cornell Lab.

See you out there!

Dark-eyed Junco

The Dark-eyed Junco is a small hooded sparrow about 6-6.5 inches. It has a rounded head, usually a whitish belly, and a stout, pale bill. It has distinguishing white outer tail feathers that flash as it flies. Dark-eyed Juncos vary across the country. Peterson lists five main subspecies groups: “Oregon” Junco, “Pink-sided” Junco, “Gray-headed” Junco, “Slate-colored” Junco, and the “White-winged” Junco.

The “Oregon” Junco is generally the most widespread species in the West and the one I commonly see at the arboretum. The male has a dark hood, brown back, and buffy sides. The female and immature are duller and have a lower contrasting gray hood. These earth tones are excellent camouflage and improve your awareness of nature. If I am not paying attention, it is easy to walk up on Juncos foraging along the trail and flush them into the underbrush.

In winter, they form small flocks. At the arboretum, I regularly count a group of around 50 birds together. They stay in constant contact with each other as they forage and move through the landscape. Their communication sounds are fairly subdued, so keep a keen ear out. Peterson describes their vocalization call as “a light smack.” They also have “clicking or twittering notes.”

For me, Juncos are warm-hearted, peaceful little birds. They can be fairly tolerant of my presence if I am quiet, move slowly, or sit still. I always look forward to hearing their gentle, trilling song in the spring. At the moment, you don’t have to go far to find them. I regularly see them foraging on grass seeds in the parking lot or the meadows just beyond the White Oak Pavilion.

Nature is an inexhaustible source of wonder. I look forward to seeing you out there.

Resources
Dark-Eyed Junco Overview, All About Birds, Cornell Lab of Ornithology. https://www.allaboutbirds.org/guide/Dark-eyed_Junco/overview. Accessed 11 Feb. 2023.

Peterson, Roger Tory, et al. Peterson Field Guide to Birds of Western North America. 4th ed, Houghton Mifflin Harcourt, 2010.

Fringecup

I was slowly walking along out at the arboretum when I was struck by the beauty of these leaves growing along the path. Their elegant sea-green color with watercolored, purple veins were soothing and refreshing. Even though this plant is common and grows throughout the arboretum, its warmth and vibrancy had me feeling as if I was seeing this plant for the first time.

Fringe cup (Tellima grandiflora)

Trailing Blackberry - Winter

In the winter, the trailing blackberry leaves turn a subtle, rich burgundy. Their subdued color blends into the landscape. On a clear, cold day in February, the leaves captured the sun’s fiery rays. The underside glowed a flaming red. It reminded me to look at life from different sides or angles to discover its illuminating nature.

Mallards

A pair of mallards have been paddling around and exploring the wetlands this winter.

Male Mallards have a dark, glossy-green head, white neck ring, chestnut-brown chest, gray body, orange feet, and a yellowish bill. They also have a noticeable black tail curl at the rear part of their bodies. Females and juveniles are mottled brown with orange-and-brown bills. Both sexes have a white bar on both sides of a blue speculum patch in the wing. You can see it in the photo of the female searching for food below the surface.

Mallards dabble to feed. You will often see them in shallow water tipped forward with their hind quarters in the air as they reach for submerged plants and animals on or near the bottom. They will also forage on the top of the water and along the shore.

Interestingly, all of the quackings you hear coming from mallards are made by females. The males don't quack. Instead, they make quieter sounds that Peterson describes as “yeeb or a low kwek.”

Mallards are powerful flyers. Migrating flocks of mallards have been estimated traveling at 55 miles per hour (All About Birds).

Also, they can launch directly into the air from the water and don't need to run across the surface to reach takeoff speed. To achieve lift-off, their first wing beat pushes against the water's surface. This is handy in places like the wetlands out at the arboretum, which is dense with vegetation.

This mallard pair is fairly tolerant of my presence if I slowly and quietly walk out onto the bridge. They are so peaceful to watch as they swim around.

Nature is an inexhaustible source of wonder. I look forward to seeing you out there.

Resources
Ehrlich, Paul R., et al. The Birder’s Handbook: A Field Guide to the Natural History of North American Birds: Including All Species That Regularly Breed North of Mexico. Simon & Schuster, 1988.

Mallard Overview, All About Birds, Cornell Lab of Ornithology. https://www.allaboutbirds.org/guide/Mallard/overview. Accessed 26 Jan. 2023.

Peterson, Roger Tory, et al. Peterson Field Guide to Birds of Western North America. 4th ed, Houghton Mifflin Harcourt, 2010.

Sibley, David. What It’s like to Be a Bird: From Flying to Nesting, Eating to Singing -- What Birds Are Doing, and Why. Alfred A. Knopf, 2020.

California Root Borer Beetle Larva

The foundation of the visitor’s center is being redone at the arboretum. Holes are being dug to pour concrete to support new beams. On one of the corners, there was a stump of an oak tree. While digging out the stump, Connor came across this huge larva boring through the middle of one of the roots, and it looks like a California Root Borer Beetle.

The California prionus beetle is 1¾ - 2¼ inches long (45-60 mm) and reddish-brown with long, deeply notched antennae. The larvae can be 4¼ inches (108 mm) and approximately ¾ inch (18 mm) at the widest point of their body.

The larva can spend from three to five years underground eating roots before reaching maturity. Based on the size of this larva, it appears to be getting close to maturity. So we found a small terrarium that wasn’t being used and set it up with soil and chunks of oak tree roots. We covered it with leaves and put a screened lid on top.

Of course, my hope is that the larva will pupate and turn into an adult beetle. I’m not sure of the survival rate of this beetle after being plucked from its home inside an oak root two feet underground. I’ll certainly let you know what happens.

Anna's Hummingbird Courtship Dive

I have been seeing the male Anna’s hummingbird performing his courtship out at the arboretum and in my backyard.

The display begins as the male rises up into the sky above the perched female. Then he dives down, swoops past, and rises above her. When he completes the arc, he will hover, face her, and sing a squeaky song. At the bottom of the dive, he makes a high-pitched chirp which is made by air whipping through his tail feathers. Look closely, and you can see him whizzing by towards the middle of the video.

If the female is receptive to all of the male’s courting, she will lead him toward the nest site, where she will perch. The male will then hold his body horizontally and fly back in forth in short tight arcs above the female. I have not seen this second phase of the courtship, and I am imagining that will mate at this time.

Males and females don’t form pairs. The Birder’s Handbook has its mating system labeled Promiscuity. This is defined as males and females mating more or less indiscriminately. With Anna’s hummingbirds, only the females care for the young. The Anna’s hummingbird nests that I have seen being built were created by the female.

It is interesting that all of this is taking place in the middle of January. I am not sure if they will try to nest this early, and I haven’t seen any nests being constructed. Perhaps the male is setting up his territory and trying to attract females for the future. That said, Anna’s hummingbirds are some of the first nests that I find in spring. I’ll keep you informed if I come across more about when they start to nest in our area.

Oregon Grape Leaves

Oregon grape is an evergreen shrub. The other day I noticed that a reddish hue had tinged many of the leaves. As I stood there observing, I saw a light green margin bordering the shadow being cast on a lower leaf. I pulled back the upper leaf and was surprised to see that where the leaves overlapped, the lower leaf was bright green. It appeared as if the leaf had a sunburn. I wondered why the leaf had become sensitive to the gentle, lower-intensity rays of the winter sun. In addition, some of the leaves were splotched with red, and others had completely turned a bright red. My thoughts mostly dissipated as my wonder became filled with beauty—the shape of the leaves, their texture, and of the juxtaposition of the red and green complementary colors.