Pileated Woodpeckers and Northern Red-legged Frogs

The pileated woodpecker is our largest woodpecker, being nearly the size of an American crow. Pileated woodpeckers were listed by the State of Oregon as a sensitive species because they have been considered an indicator species for mature and oldgrowth forest, and because they are sensitive to clearcutting and other forms of timber harvest. However, recent research has shown that in western Oregon, this species will nest and feed in younger forest stands.

Studies have shown that nesting and feeding holes created by pileated woodpeckers are used by many other species that nest in cavities in trees. These other species are called secondary cavity nesters, because they do not create their own nest cavities, so they must use existing ones. Of these secondary cavity nesters, six are bird species known to occur in forested areas of the South Hills (western screech-owl, northern pygmyowl, northern saw-whet owl, Vaux’s Swift, Northern Flicker, and Brown Creeper).

The pileated woodpecker has been considered a “keystone habitat modifier,” because it plays a unique and important role in creating and maintaining habitat for other species.

Recent surveys show that numbers of Pileated Woodpeckers are increasing in western Oregon, and they are considered common to uncommon throughout western Oregon. In the Willamette Valley, suitable habitat for pileated woodpeckers probably did not commonly exist prior to Euro-American settlement and suppression of seasonal fires. Before the suppression of these fires, oak savanna habitat dominated the foothills of the Willamette Valley. As fire was suppressed, the Douglas fir/western hemlock habitat (used by the woodpecker) has overtaken the historic oak savanna and oak woodland habitat. Without this human-induced habitat change, there would not be adequate habitat to support the pileated woodpecker in the valley foothills. Based on information from knowledgeable bird-watchers in Eugene, the Pileated Woodpecker is commonly seen in both developed and undeveloped areas throughout the South Hills.

The Northern Red-legged Frog is a medium sized frog with pinkish red markings on its hind legs. This species is designated by the State of Oregon as a sensitive species, due to the decline in its numbers, especially in the Willamette Valley where it was formerly abundant. The reasons for its decline are unknown, but pesticide pollution and competition with the introduced bullfrog are suspected factors.

The Northern Red-legged Frog breeds in marshes ponds and streams, generally in January and February. During the rest of the year, they inhabit cool, moist forests, venturing away from the stream after the breeding season. They are known to travel up to 1,000 feet away from water during this time, especially under wet conditions. Redlegged frogs have been documented at one site in the South Hills and are suspected to occur at other sites as well. They are most common in habitat sites with shallow, south-facing slopes. The closely-related California Red-legged Frog, found in southwestern Oregon and California, is a federally-listed threatened species.

- Main Habitats & Wildlife Page -
- Upland Prairies & Rock Outcrops - Oak Woodlands & Oak Savannah -
- Willamette Valley Ponderosa Pine - Pileated Woodpecker & Norther Red-legged Frog -
- Habitat for Wildlife - Habitat for Rare Plants -