Neighborhood Naturalist, Spring 2019 by Neighborhood Naturalist

neighborhood naturalist CORVALLIS, OREGON — SPRING 2019

eet-weet! A Spotted Sandpiper scurries over the smooth river cobbles, pausing to bob its tail up and down. Peet-weet! it cries again, its voice ringing over the sound of flowing water. Another sandpiper rushes in, wings raised in a threat display, and a chase begins. When neither bird yields, they engage in fierce combat, each trying to peck the head and eyes of the other bird or flip it onto its back.

concedes, fighting can ultimately settle the dispute. And that same principle is at work when Spotted Sandpipers battle it out, except there’s a twist: those battling birds are female.

Of course, female birds of other species are fully capable of fighting if necessary. But for the Spotted Sandpiper, the typical sex roles are almost entirely reversed, with the female being larger, more aggressive, and performing courtship Springtime means breeding season for local birds, when displays to males. Males incubate eggs and perform most competition for mates and good territories drives males to of the parental duties, including brooding young chicks. risk everything in physical fights. Singing and displaying The hormone prolactin helps drive parenting behavior in helps reduce the need for violence, but when neither party birds, and male Spotted Sandpipers have more prolactin

Spotted Sandpiper article, photography and illustration by Lisa Millbank

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than females do. Likewise, the relatively low androgen level of females increases greatly in the spring, which correlates with their aggressive territorial behavior. The vast majority of our local birds breed as monogamous pairs. Spotted Sandpipers take the sex role reversal even farther, being polyandrous. Polyandry is a rare mating system in which a female breeds with more than one male in a season. She will control a large territory, and she’ll attempt to court and, eventually, mate with all of the males within it. Any other female intruding on the territory is evicted immediately. A male also competes against other males, so each has his own sub-territory within the female’s territory. Not all females can acquire multiple males, and they’ll remain in monogamous relationships.

Breeding All Year Winter Migration

As soon as a pair forms, they begin to scratch little depressions into the ground, usually shaded by vegetation. Most of these nest scrapes are never used as nests, but the process of making them helps with pair-bonding. The female usually initiates the scrape that will actually be used as a nest, and the male finishes it. The birds pull bits of the surrounding vegetation into the scrape, and then shape the cup by pushing and rolling the breast and belly into the material. The female then lays one egg each morning, Most sandpiper species breed in the tundra or taiga regions of North America, but the Spotted Sandpiper also breeds across most of the usually for about four days. United States. Although most migrate to warmer climates, a few may be found wintering in the Willamette Valley.

While the male begins the three-week incubation, the female may start courting one of the other males in her territory so that she can lay another clutch. If she has only one male, she’ll help him with incubation and the care of the chicks. Laying many clutches in a season requires a tremendous investment of energy, and that’s one factor limiting polyandry in birds. A Spotted Sandpiper egg is about 20% of the female’s body mass, and the clutch is usually about four eggs. Females lay up to five clutches in a season. Since Spotted Sandpipers live along rivers and lakeshores, there’s usually no shortage of invertebrates and small fish. The abundance of food may help fuel the egg production that is essential for the Spotted Sandpiper’s unique mating arrangement. Just a couple of other birds of our region exhibit polyandry, with female Red and Red-necked Phalaropes having a sequentially polyandrous mating system that’s similar in most aspects to the Spotted Sandpiper. A female Acorn Woodpecker may mate with multiple males in her colony, but then she, all of the males, and other females in the colony take part in raising the young as a group. Spotted sandpipers prefer areas of mud, river cobbles and shallow water for hunting. Nesting areas typically include scattered shrubs.

Spotted Sandpiper chicks have fuzzy down coats, but they’ll need to be brooded in cool weather until contour feathers replace the down. Within two hours of hatching,

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Aquatic invertebrates make up a large part of a Spotted Sandpiper’s diet. This sandpiper has caught a stonefly nymph.

the tiny chicks can walk along the shoreline, picking at small invertebrates. When a parent gives an alarm call, the chicks scurry into the closest vegetation and hide there, listening for an “all-clear” call that lets them know it’s safe to emerge. By the time they’re three weeks old, they can fly pretty well, and are nearing independence from their parents. As summer winds down, the adults lose their bold spots and molt into a fresh set of feathers. At this point, adults and young birds look nearly alike. The southbound migration begins as early as July, with a peak in mid-August. Like most shorebirds, Spotted Sandpipers are strong flyers, and some fly all the way to Peru or Brazil. A few Spotted Sandpipers spend the winter in the Willamette Valley. Whether wearing the fancy spots of their breeding plumage or their more subdued winter plumage, Spotted Sandpipers are easy to identify by their peculiar tail-bobbing motion. “Teeter-tail” (or the more colorful “teeter-ass”) is an old colloquial name for the Spotted Sandpiper, also applied to the American Dipper. Tiny chicks instinctively bob their back ends up and down just a half-hour after

When in flight, the Spotted Sandpiper displays white stripes on both the upper- and undersides of the wings. This individual lacks spots because it is in nonbreeding plumage.

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they hatch. This behavior is clearly important to them, but the reason why is unknown. Plenty of ideas have been put forward. Does the motion camouflage them against moving water? Is it a visual display to show their ownership of a territory? Does the sudden motion flush prey out of hiding places? None of these explanations is very satisfactory. In addition to the tail-bobbing, the Spotted Sandpiper’s flight pattern is unique and easy to recognize. They skim just over the water’s surface with shallow, stiff wingbeats, showing white stripes on their wings. Spotted Sandpipers can swim and dive if necessary, but they prefer to stroll through shallow water, over rocks, or across mudflats. Most Spotted Sandpiper habitat is fairly open, making it difficult to hide from predators. In these circumstances, diving may be their only option. I’ll never forget what I witnessed from my raft while on a lazy float trip down the Willamette River. I was watching a Spotted Sandpiper as it foraged along the rocky shoreline. The sandpiper gave a sharp cry and abruptly plunged into the water, and before I realized what was happening, an immature Peregrine Falcon was plummeting toward the spot where the sandpiper had just been. The falcon realized that the opportunity was lost and veered away. The little sandpiper swam some distance underwater before emerging, probably pretty shaken up from its near-death experience! Perhaps it wouldn’t have been able to escape the talons of a more experienced adult Peregrine. Most of our local Spotted Sandpipers depend on gravel bars and mudflats along rivers. Human activities that impact such sites directly include riding off-road vehicles on gravel bars, or even boaters unwittingly camping too close to nests. However, habitat modification, such as armoring riverbanks with riprap, or building dams that impede the movement of gravel and sediment downstream, probably have a much greater impact. Though they face some obstacles, Spotted Sandpipers are still common in our region. The decades-long fight to improve water quality in the Willamette River system has allowed Spotted Sandpipers and their prey to rebound.

This simple nest, with an incomplete clutch, was found in the subalpine lake basin around Mt. Jefferson. It was scratched into the debris among the heather.

A downy young chick explores the riverbank. The chick can find all of its own food, but still needs to be brooded by a parent when the weather is cold.

Next time you visit the river, or during a summertime paddle outing, watch those gravel bars and cobblestone riverbanks—home of the vocal, tail-bobbing Spotted Sandpiper and its most unusual lifestyle.ó

Watch a video and listen to the sounds of Spotted Sandpipers www.neighborhood-naturalist.com

An older chick molts out of its down into adult-like winter plumage. As summer draws to a close, adults lose their spots, and both young birds and adults closely resemble one another.

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Red Columbine article and illustrations by Don Boucher photography by Lisa Millbank

Many field guides call it Red Columbine (Aquilegia formosa). Sometimes it’s called Western Columbine or Crimson Columbine. These aren’t unique or creative names, because there are other red-colored columbines. Those who live east of the Rockies are familiar with A. canadensis, also going by the name Red Columbine. A. One of the reasons I love to find Red Columbines is formosa isn’t even the only red-colored columbine in the that their red color almost glows among the common west; in the Southwest, there are five others, and one of yellows, purples, whites and pinks found in meadows. Red those is called Western Red Columbine (A. elegantula). Columbine is even more gratifying when viewed closely. We don’t have to worry about this in our area because The ornate blossoms nod from spindly stems. Deep crimson spurs stand above the broad red sepals, followed by nectar A. formosa is our only native columbine, and there are no well openings edged with yellow, and hanging below are introduced species in the wild. It’s also found throughout Oregon, in every corner, from the coast and the valleys frills of yellow anthers. to subalpine meadows, but not in deserts. It lives in a While the lovely flowers are a delight for naturalists to broad range of habitats, usually in close association with see in the wild or in the garden, Red Columbine plays a forests, whether conifer, broadleaf, or mixed. They like key role in botanical research. ome wildflower field guides are arranged by color, and the largest sections are always white and yellow. Next are the blue and red sections. But most of the “red” flowers are pink to magenta, with only a few bright red standouts.

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forest meadows, especially along the edges, in open canopy forests. Some grow in wet prairies and other moist, sunny situations—one of the biggest plants we’ve ever seen grows in a ditch along Hwy. 20 north of Corvallis. There’s only one other native columbine in our state, Yellow Mountain Columbine (A. flavescens), which lives in the mountains of northeast Oregon.

Sepals

Hummingbirds are common pollinators of Red Columbine, but bumblebees and butterflies may also visit. Among columbine species, the length of the spurs, which hold the nectar, correlates with the length of their pollinators’ mouthparts. Similarly, the color of the blossom appeals to its preferred pollinators’ vision. Columbines with short spurs are visited more often by bumblebees, and these are blue or purple, colors to which bees’ eyes are most sensitive. Medium-length spurs, like Red Columbine, get more attention from hummingbirds, because red is particularly attractive to them. Hawk moths, also known as

Spur

Modiﬁed Petal

Blade Stamens

Stigmas

What appear to be petals are actually sepals that emerge from behind the modified petals. Since the flower hangs down, “behind” means toward the base of the flower. The petals include the yellow blades in front of the sepals, and the nectar-filled spurs that extend behind the sepals.

The mid-stem leaves (above) and the basal leaves (below).

The fruit is a cluster of five tube-like capsules filled with seeds. In maturity, they dry out, and the tops open to release the black, shiny seeds. Neighborhood Naturalist, Spring 2019 v17#1 • page 6

sphinx moths, have very long proboscises, and are primary visitors to long-spurred columbines, like Sierra Columbine (A. pubescens, found in California). Nocturnal hawk moths have the remarkable ability to see color at night, and they prefer pale-colored flowers. Indeed, many long-spurred columbines have pale colors in their blossoms. Diurnal hawk moths will visit flowers of most any color or shade. Some bumblebees cheat the system by chewing open the long spurs to access nectar. Columbines colonized North America from Asia, by way of the Beringia land bridge during the last ice age, between 40,000 to 10,000 years ago; fairly recently in evolutionary terms. Although North American columbines vary in color and spur length, they are closely related, and hybrids are possible where ranges overlap. Columbines are in the buttercup family, Ranunculaceae, even though they don’t seem to resemble the plain, simple appearance of buttercups. Some members of the family have simple flowers, like buttercups and anemones, while some come in ornate or bizarre forms, such as larkspurs, monkshoods, meadow-rues, and baneberries. Botanists use flower structure, among other features like genes, to help determine the taxonomy of any given plant. To a botanist, a buttercup, an anemone, a larkspur and a columbine are all alike in their fundamental floral structure. I won’t go into the botanical details, or show flower diagrams here, but here’s a rough analogy: imagine flower shapes as if they were typefaces. A columbine flower is like a calligraphic typeface among the buttercup family, with fancy tails and curls. A buttercup is like Helvetica, compact and simple, but broadly effective. Structurally, columbine and buttercup flowers have the same alphabet and are written in the same language, but are used for different occasions. In the case of columbines, those occasions are visits from specific kinds of pollinators.

An immature Anna’s Hummingbird visits a Red Columbine

Red Columbines decorate our native plant garden with brilliant red bursts from mid- to late spring, and if watered and dead-headed, they may bloom again during the summer. We used to grow the non-native cultivar of the purple Common Columbine (A. vulgaris), but we gave them away. We didn’t want them to hybridize with our Red Columbine so we could ensure that the seeds they produce are purely native. Look for Red Columbines during spring hikes in local forests, or try growing them at home. Not only are they delightfully extravagant, they’re also useful to botany and a wonderful example of adaptation and speciation. ó

Columbines serve as models of speciation and adaptive radiation. Species that are otherwise genetically closely related vary widely in appearance, and have colonized all kinds of habitats in a short amount of time. Some species have small ranges, living in unique climates and becoming finely tuned to their local pollinators. Red Columbine’s genome was fully sequenced and made available to scientists. The genome is used as a benchmark among other key plants. When botanists need to compare the genes of a plant to other plant groups, Red Columbine is often used as a representative of the Ranunculales order (which includes a few other families, in addition to Ranunculaceae).

Red Columbine is found throughout much of western North America

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Flower Types of the Ranunculaceae Family Western Meadow-rue (Thalictrum occidentale) is an oddball in this group. It’s wind-pollinated, and male and female flowers occur on separate plants. Male flowers, shown here, have sepals and anthers but no petals. The female flowers are similar, with only sepals and a cluster of pistils in the center.

Our local wildﬂowers display the diversity of ﬂoral shapes found in this plant family. Ranunculaceae gets its name from the buttercup genus, and buttercups are common and simple representatives. Columbines and larkspurs have more complicated blossoms with ornate structures.

Western Buttercup Ranunculus occidentalis

Red Columbine Aquilegia formosa

Tall Larkspur Delphinium trolliifolium

Red Baneberry (Actaea rubra) has a raceme of small blossoms. The ﬂowers have reduced petals that blend in with the anthers.

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Oregon Anemone (Anemone oregana) is simple, much like a buttercup.

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