Three of these birds have made a comeback, and we have hope for the fourth. All of them tell us something about the history of land use in the Willamette Valley.
Champoeg is one of the best places to see real western bluebirds— small, quiet, and intensely blue. Unfortunately, it also one of the few places left where you can see western bluebirds.
Before settlement began in the early 19th century, the Willamette Valley provided an ideal habitat, and bluebirds were extremely common. The birds nested in cavities— holes in old or dead trees—in the thick forests that grew along the rivers and streams. During the day, they flew out onto the prairies to find insects and berries.
Settlers plowed the prairies to create their farms. But the 19th-century pattern of small farms, interspersed with clearings and woodlands, was still good bluebird habitat. Even the old-fashioned wooden fenceposts often had cavities for nests. Bluebirds remained a common sight into the early 20th century.
Problems began when the valley shifted to largescale agriculture. Bluebird homes and food sources were cleared away to create the large fields we see today. House sparrows and European starlings—cavity- nesters introduced from England—pushed the remaining bluebirds out of the lowlands and into the hills. By the mid-1940s, only a few bluebirds could be found in places like Ladd Hill near Sherwood, or Parrett and Chehalem Mountains near Newberg.
In the 1970s, a bird-lover named Hubert Prescott began putting up nest boxes and monitoring bluebird populations. Volunteers joined in, and then organized the Prescott Bluebird Recovery Project, a non-profit organization. By erecting nest boxes in the right locations, controlling predators such as cats and raccoons, banding and monitoring the birds, and occasionally supplying a little extra food, they make it possible for bluebirds to return to Champoeg and other grassy areas in the Willamette Valley.
Unfortunately, the bluebird comeback depends on human intervention. In all likelihood, if the volunteers were to suddenly stop their efforts, the bluebird population would dwindle to its pre- 1970s level.
Western meadowlarks, Oregon’s state bird, were once common throughout the state. Today, while they remain common in central and eastern Oregon, they have virtually disappeared from the Willamette Valley. At Champoeg, a dozen pairs or more may pass through in winter, but are gone by the spring nesting season.
Unlike bluebirds, meadowlarks nest on the ground, in grassland. Although large-scale agriculture has greatly reduced meadowlark habitat, there should still be enough grassland to support at least small populations. Yet something discourages them, and they will not stay.
The problem may be caused by the exotic grasses, such as meadow foxtail, that have been introduced into the Willamette Valley. They grow taller and thicker than the native species they displaced, perhaps making it impossible for the birds to nest. In 2004, hoping to find a grass length that would satisfy the birds, the park tried a special mowing schedule that created several areas with different grass lengths. Unfortunately it didn’t work, and the mowing was halted.
Our next hope lies with the park’s dry prairie restoration project. By 2009, 40 acres of native grasses should be well established. If this fails to attract nesting meadowlarks, we will have to wait for ornithologists to come up with another idea.
It has been many years since bald eagles have nested at the park. But they do nest elsewhere along the Willamette River, and there’s no reason they couldn’t do so here as well. They can be seen occasionally at any time of year, but are most common in spring.
Ospreys (sometimes called “fishhawks”) are seasonal visitors, arriving in early April to nest and raise young, and then going south again in early September. For several years a pair has been nesting on our osprey pole by the wet prairie. Other pairs nest in the vicinity, making ospreys a common summer sight and sound.
Both eagles and ospreys, along with many others species, nearly disappeared a few decades ago. Although habitat loss was a problem, the main culprit was a pesticide called DDT. Heavily used after World War II until it was banned in 1972, DDT was once very effective against insects, and helped to push back mosquito-born diseases such as malaria.
Unfortunately, the chemical accumulated in predator birds, causing the shells of their eggs to be too thin for embryos to develop. Populations collapsed. In 1976, only 11 osprey nests could be found in the Willamette Valley. There were no eagle nests at all.
But with the removal of DDT from the market, and with human help, both these birds have made a remarkable comeback. In the year 2000, 202 osprey nests were counted in the valley, and there are many more than that today. As of 2003, up to 25 pairs of bald eagles were in the valley, with 458 total pairs in Oregon and along the lower Columbia River.