Neighborhood Naturalist Fall 2016

neighborhood naturalist CORVALLIS, OREGON — FALL 2016

Red-breasted Sapsucker article and illustrations by Don Boucher, photography by Lisa Millbank

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Red-breasted Sapsucker was tapping on one of the street trees in downtown Corvallis. While it was on the other side of the trunk, Lisa and I carefully approached, and then waited patiently for it to appear. When it circled around to our side of the trunk, it didn’t seem at all concerned with our presence. It was oblivious to cars driving by and people passing on the sidewalk, so we took the liberty of approaching within ten feet of it.

While most woodpeckers bore into wood in search of hidden insects, this sapsucker was there to drink sap.

Though other woodpeckers do drink sap on occasion, a Red-breasted Sapsucker makes a living from it. Tree sap isn’t a nutrient-rich source of food, so a sapsucker must drink large quantities of it.

There are two kinds of vascular tissue in trees that transport sap; the kind that draws sap up from the roots to the leaves is called xylem; and the type that distributes nutrients to all parts of the tree is called phloem.

We watched the sapsucker chisel a little bit of bark from the tree. We were close enough to see the live green tissue in the hole it had excavated. Clearly, it had visited this tree A Red-breasted Sapsucker extracts sap with strategy and many times before, because there were rows of similar holes precision. Typically, it drills into the phloem, where the sap of varying ages; some where the sap was oozing out, and contains sugars and nutrients synthesized by the leaves. others where the bark had healed.

Xylem is mostly water with traces of dissolved minerals for most of the year. But in early spring, when xylem sap I’ve gotten this close to a Red-breasted Sapsucker and is rich in sugars moving up from the roots, sapsuckers will other woodpeckers before, so this wasn’t an extraordinary drill to the exact depth of the xylem. Commercial maple experience. Sometimes woodpeckers can be so focused on syrup producers also tap xylem sap in early spring. their work that they pay little attention to a person standing calmly nearby. In this case, getting such a close look at a In addition to tapping the bark at a precise depth, a sapsucker gave us a glimpse into its unique lifestyle. sapsucker has a technique that goes beyond simply stabbing Neighborhood Naturalist, Fall 2016 v14 #3 • page 1

Interestingly, Red-breasted Sapsuckers use a broad range of tree species, including both conifer and broadleaf trees, but no outstanding species preferences have been documented. They use conifers most often in winter because the sap is more readily available. But, they are able target individual trees that produce more nutrition. Trees that are under stress have more nutritious sap than healthy trees. In unhealthy trees, the sap flow may be restricted by physical damage, fungal infections or scarring from insect infestations. A sapsucker will find areas under the bark where the resulting sap pressure is high. A sick tree will also increase nutrients in its sap, such as amino acids, to repair damaged tissue. So for a sapsucker, it’s more about the tree than the habitat. Though they pay little attention to environmental factors, like soil moisture, soil quality or This dishevelled Red-breasted Sapsucker won the rights to our proximity to nest sites, there’s a tendency to use trees near backyard plum tree after a vicious fight with another sapsucker. One streams or in orchards. bird yanked the other off the tree trunk, and they wrestled violently in the wet grass. The feathers on the head and breast are dark gray with red tips, so when the bird is wet, the tips clump together and the red is largely hidden.

a hole into the bark. When prospecting for the best sap, it drills one hole after another, in orderly, horizontal bands.

When it finds a productive spot in the bark, it switches tactics. With much skill and accuracy, it neatly chisels a somewhat rectangular shape into the bark and peels off a little piece. The sap pools up in this hole, called a sapwell, much more effectively than if it were merely a puncture wound. Within one to three days, a sapwell stops flowing as the tree heals itself. Phloem sap pressure builds up above the healing sapwell because the scar tissue dams the downward flow. The sapsucker cuts the next sapwell strategically above the healing sapwell to maximize sap flow. When this process is repeated, the sapsucker creates columns of sapwells, with the most recent sapwells higher on the tree.

There are nuances to a sapsucker’s handiwork that aren’t understood. Biologist Laurie Eberhardt, who studied Yellow-bellied Sapsuckers extensively, tried to replicate their work without success. She experimented on various tree species, using different tools like knives, chisels and more, but could neither get as much sap to flow, nor for as long, as the sapsuckers’ sapwells she studied. Some biologists speculate that there may be chemicals in a sapsucker’s saliva that help the sap flow, but no evidence for this has been found so far. For now, humans can’t quite match the sapsucker’s skills at making sapwells.

Red-breasted Sapsuckers invest a lot of time and energy into finding and managing their sapwell trees. When we encountered that sapsucker in downtown Corvallis, it was working steadily and minding its own business. A sapsucker’s nonchalant attitude changes if a squirrel or another kind of bird visits its sapwell tree; it will vigorously

Red-breasted Sapsucker

Northern Flicker

The Red-breasted Sapsucker’s tongue has a brush-like tip for collecting sap. The base of the tongue is anchored at the back of the skull. The length of the tongue is similar to most birds, unlike the extraordinary tongue length of most other woodpeckers, such as the Northern Flicker.

In most woodpeckers, like the Northern Flicker, the tip of the tongue has small barbs. They have remarkably long tongues, which enable them to reach insects deep inside crevices. The forked base of the tongue wraps around the entire skull, extending all the way into one of the nostrils.

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chase away the intruder. If another sapsucker shows up Red-breasted Sapsucker breeding, migration, and (except for its mate or recent offspring), the conflict can be dispersal aren’t well-studied. We know that they prefer more intense. Such interactions will start with aggressive to breed in moist conifer forests up to 8,000 feet. They posturing and vocalizations, which can escalate to physical make nesting cavities in large-diameter snags, or living combat. The fight may involve wrestling each other to the ground and striking out with their bills and feet.

While Red-breasted Sapsuckers are efficient at getting the most from tree sap, they still need to eat other foods.

When they make sapwells, they sometimes eat pieces of living bark tissue such as soft, young cambium and bast fibers. The food value of this inner bark is best in early spring. They can get their animal protein by preying on insects that feed from their sapwells, and on other insects and spiders that get trapped by the sticky, drying sap.

They’re also pretty good at catching flying insects. Redbreasted Sapsuckers like fruit too; I’ve encountered them eating Western Poison-Oak fruits and apples.

Drumming Woodpeckers drum on hollow wood, metal or other resonating objects to make noise, which results in attracting mates and/ or defending territory. For many species, the pattern is a simple staccato, like these sonograms of a Downy and Pileated Woodpecker.

Downy Woodpecker drumming

Here, a Red-breasted Sapsucker drinks from a sapwell. Notice how the tree below has a large area with wet and darkened bark; a pattern that can be seen from further away than the sapwells. Keep this in mind when you search for sapsuckers.

Pileated Woodpecker drumming

The Red-breasted Sapsucker’s drumming pattern is unmistakable and unique. In the sonogram below, you can clearly see the double-strike, “syncopated” rhythm.

Their most common vocalization is a single, descending, nasal earrrr! call. They make other squeals and chatters, especially during mating or fighting.

Red-breasted Sapsucker drumming

See and hear Red-breasted Sapsuckers in a video at www.neighborhood-naturalist.com

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trees with decaying cores, often near streams. The cavity needs to be big enough to hold as many as six young.

Large trees provide more insulation than smaller trees, helpful when nests have to endure cold mountain nights. In addition, large-diameter trees allow sapsuckers to excavate deep cavities high up the trunk, which can prevent some predators from reaching into the nest. Their populations are stable, but logging that reduces the number of larger trees and snags in forested areas will negatively impact their

The Benefits of Sapsuckers Sapsucker wells are valuable to other wildlife. When a Redbreasted Sapsucker isn’t around to defend its sapwells, others may partake in the sugary sap, most notably Rufous Hummingbirds. Males migrate in March, when flower nectar is scarce, but sapsucker trees can be a dependable source of energy. At other times of the year, both Rufous and Anna’s Hummingbirds might include a sapsucker tree in their daily nectar rounds or even nest near these sites. Other birds have been observed using sapsucker wells, such as Ruby-crowned Kinglets, White-crowned Sparrows, Orange-crowned Warblers and Wilson’s Warblers. Other wildlife such as squirrels, jumping mice and insects drink sap from sapsucker wells. Mourning Cloak butterflies are active on sunny winter days, and depend on sap when few flowers are in bloom.

Rufous Hummingbird

Mourning Cloak

A parent feeds a nestling in a tree cavity

nesting success. But even in the most pristine habitats, they aren’t numerous.

Red-breasted Sapsucker nests may be easier to find in late spring or early summer when the nestlings are near fledging. They make incessant, wheezy calls, whether or not the adults are nearby. When youngsters leave the nesting area, it isn’t known how far they disperse.

In the Willamette Valley, good numbers of sapsuckers appear at lower elevations in winter, often away from their breeding areas. Even if you don’t live near the woods, you may get a sapsucker visiting your backyard in winter. In our area, it’s not clear if wintering birds are just moving downslope from nearby mountains, or if they’re migrating from hundreds of miles to the north.

Fall and winter are good times to find them in cities and residential areas. They’re fairly quiet birds this time of year.

You can listen for their occasional nasal calls, but the best way to track down a sapsucker is to find an active sapwell tree. Look for rows of holes with oozing sap. Stake out a sapsucker’s tree, and you’ll likely get a close look. ó

Sapsucker Damage Northern Saw-whet Owl

Douglas’ Squirrel

Former sapsucker nesting cavities benefit creatures who can’t make their own nesting cavities. Chickadees, nuthatches, wrens, small owls, Western Bluebirds and some squirrels depend on holes like old sapsucker cavities.

Red-breasted Sapsuckers are implicated in the damage of orchard and other beloved trees. While sapsucker damage can stress a tree, they have a tendency to select trees that are already damaged or diseased. It’s hard to determine if sapsucker activity actually killed a tree, or if the death was inevitable from other factors. But a sapsucker’s work certainly doesn’t help the condition of a stressed tree. If you really want to stop sapsucker activity, one reliable method is to wrap the affected trunk in burlap. Sapsucker damage in a forest is negligible, since they only affect a small number of trees.

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Sapsucker Species Comparison There are three species of sapsucker that are common in Oregon.

Williamson’s Sapsucker

Hybrids are rare and there are only records of Red-naped x Redbreasted hybrids in Oregon. The Yellow-bellied Sapsucker, shown here for comparison, is found east of the Rockies.

Red-breasted Sapsucker The only species of sapsucker in the Willamette Valley and western Oregon.

Males and females look alike, but young birds lack the cranberry-red head and breast.

Very distinctive in appearance, and males and females look quite different. This species has the fewest reported sightings in western Oregon. male

female

Red-naped Sapsucker

adult

juvenile

■ breeding ■ all year ■ non-breeding

Similar in appearance to the Yellow-bellied Sapsucker. The most notable distinction is the red patch on the back of the head.

Males and females are similar. The Red-naped is the most likely vagrant to be seen in western Oregon.

Yellow-bellied Sapsucker

A rare vagrant in Oregon; a single male returned to E.E. Wilson Wildlife Area for several recent winters. Males and females are similar. It’s not the only sapsucker with a yellow belly. In fact, the adults of all sapsucker species have yellowish bellies.

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Red-Osier Dogwood article and photography

by Lisa Millbank

I

stood on the Marys River bridge in Corvallis on a sunny fall day, watching a quivering, trembling thicket of red and purple leaves. On each cluster of small white berries was an American Robin, flapping wildly to balance on the slender red twigs. Dozens of birds squabbled and thrashed around, gobbling berries and competing for the best picking spot in this riverbank thicket.

Few fruits can tempt birds the way Red-Osier Dogwood berries do, but the plant also has a long history of human use that continues today. It grows in rich, moist soils, near streams or in broken woodlands, across most of northern North America. Cornus sericea goes by many other names: Creek Dogwood, Red Willow, American Dogwood, and the local subspecies is sometimes called Western Dogwood.

Despite its common name, you wouldn’t necessarily guess that this tall shrub is closely related to the showy Pacific Dogwood tree and the charming Bunchberry, a familiar trailside wildflower in the Cascades. While its relatives have large white bracts that resemble petals, RedOsier Dogwood has tiny flowers borne in flat clusters. The

blossoms attract bumblebees, flies, butterflies and other pollinators. Once pollinated, the berries develop, ripening from green to white or bluish-white. Soon, a hint of color appears on the leaves, typically deepening to purple, scarlet or maroon in autumn. Once the leaves have fallen, bright red twigs glow against winter’s subdued palette.

For wildlife, though, the fruit is the main attraction.

Though they’re commonly called berries, botanically, they’re drupes like peaches or cherries. Inside the fleshy little fruit is a single hard-shelled pit, with two kernels inside.

Fruit-eating birds, such as American Robins, Western Bluebirds and Cedar Waxwings, relish the little white berries and swallow them whole. Most dogwood pits pass through their digestive tracts intact. Red-Osier Dogwood depends on these birds to deposit its seeds away from the parent plant, just as many other berry-producing plants do. Dogwood berries are so beloved by wildlife that the bushes are typically stripped of every last berry. Only then do the fruit-eating critters turn to less palatable fare, such as Common Snowberry and rose hips.

Some animals may prefer to eat the kernels inside the berry, which offers no benefit to the plant. I’ve watched Golden-crowned Sparrows mashing the berries around in their bills until the skin and pulp fall off. They seem to crack the pit open to extract the kernels, though it’s hard to see just what they’re doing. Townsend’s Chipmunks also harvest the berries, and I suspect that they eat the fruit and then gnaw through the pit to the kernels inside.

Red-Osier Dogwood attracts fruit-eating birds and other wildlife, such as this American Robin and Townsend’s Chipmunk.

The leaves and twigs are browsed by American Beavers, Blacktail Deer, Elk and rabbits, and many birds find good nesting habitat in the dense streamside thickets.

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2-3 mm

Each berry contains one small pit, with two kernels inside.

Dogwoods have opposite leaves, with two leaves growing from each node on the stem.

Not only is Red-Osier Dogwood valuable to wildlife, it’s been used by native peoples across North America. We can only assume that the local Kalapuya found many uses for it, though much ethnobotanical information about them has been lost. Anthropologists do know that not all tribes ate the tart and bitter berries, but those who did often blended them with Serviceberry, Chokecherry or other fruits, possibly to improve the flavor. They could store cakes of pounded, dried dogwood berries for long periods of time.

Osier is a French term for a type of willow used for basketry. And like its namesake, the supple red branches of Red-Osier Dogwood are often featured in Native American basket weaving. Baskets from the Columbia River region often feature red stripes of dogwood to contrast with dark willow stems.

Some tribes have used the bark to make dyes of various reddish to black hues, and the straight shoots were used for arrow shafts. The dense, hard wood could be carved into small tools and utensils. Reportedly, some tribes also used tannins from the inner bark for preserving animal hides.

Throughout the range of Red-Osier Dogwood, people

In autumn, Red-Osier Dogwoods turn red to purple.

used it for various medicinal or ceremonial purposes. Some California tribes whitened their teeth with peeled twigs, and others used the bark to make an eyewash, a treatment for skin problems and a remedy for dandruff. Teas made from the bark were used as a general tonic and for coughs, headaches, kidney problems or digestive issues. But the same plant also served as an emetic for Navajo ceremonies, so it should be used with caution internally.

Across the plant’s broad range, many Native American tribes shaved off the inner bark and prepared it for ceremonial smoking, and some people continue this tradition today. They usually blended Red-Osier Dogwood with other herbs. Both historical and modern users have described psychoactive effects when smoking Red-Osier Dogwood, but others refute such claims.

In modern times, the year-round appeal and hardiness of Red-Osier Dogwood has made it a popular landscaping shrub. An Asian species, Tatarian Dogwood (Cornus alba), is almost identical. Plant breeders have developed cultivars of both species, some having golden stems, variegated leaves, or a dwarf growth habit, and the two species may be confused in the nursery trade. Although ornamental cultivars of either dogwood are suitable for wildlife-friendly

These ornamental cultivars of Red-Osier Dogwood, or the closely related Tatarian Dogwood, show variegated foliage or golden twigs and leaves. Some cultivars have also been bred to display a variety of bright colors in autumn.

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Berries are green when immature.

Ripe berries are white or bluish-white.

An illustration of a single flower

landscaping, native plant advocates recommend using wild-type plants from our bioregion. Specialty native plant nurseries usually provide local Red-Osier Dogwood stock that is best suited to the Willamette Valley’s climate.

the plants are still dormant. While you can buy plants, you can also try propagating them yourself. Clip long shoots from wild plants and simply drive them deeply into moist soil. Most should take root in the spring and begin to grow.

Within a few years, your cuttings will attract pollinators If you’d like to add Red-Osier Dogwood to your yard, the and birds, and provide beauty in every season. ó best time to do it is in late fall through early spring, while

Other Native Dogwoods

Pacific Dogwood (Cornus nuttallii) Pacific Dogwood is conspicuous in mid-spring, when its broad white floral bracts glow like stars against dark conifers. This tree turns deep red in autumn, and bears fruit that attracts wildlife.

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Bunchberry (Cornus unalaschkensis) This cheerful little woodland plant is common in moist forests in the Cascades. The white-bracted flower cluster and bright red berries grow atop a whorl of deeply-veined leaves.

2855 NE Lancaster St. Corvallis, OR 97330 541-753-7689 donaboucher@gmail.com www.neighborhood-naturalist.com ©2016 Don Boucher and Lisa Millbank

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