Downy Woodpecker

A Downy woodpecker getting ready to drum an old snag.

NPS/Neal Lewis

 

Downy Woodpecker

Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Piciformes
Family: Picidae
Genus: Picoides
Species: Picoides pubescens

 

Introduction

More often seen in winter at suet feeders than in the woods, “Downys” are year-round residents of ShenandoahNational Park and in most of their range. Downy Woodpeckers hold the distinction of being the most common and smallest American woodpecker. In ShenandoahNational Park, Downy Woodpeckers are among the relatively few bird species regularly seen during the winter.

Physical Description

Downy Woodpeckers are between 6 and 7 inches (14-17 cm) in length and their wingspan is between 10 and 12 inches (25-30 cm). Adult birds weigh between 0.74 and 1 ounces (21-28 g). The downy has a white breast with black and white back. Males sport a red nape. The most similar species is the hairy woodpecker, which has nearly identical plumage. However, the Hairy Woodpecker is larger (7.5 inches) and has a longer bill.

Life Span/Reproduction

As with many small birds, Downy Woodpeckers have a relatively short lifespan. A five year old downy is an old bird, as the median lifespan of Downys is between one and two years. Despite this, a Downy Woodpecker that was captured and banded at the San FranciscoBay bird observatory was recaptured 11 years and one month later. When originally captured, its plumage indicated that it was at least a year old, meaning that this bird was twelve or more years of age. This capture and recapture do not represent the greatest time span on record; according to the Bird Banding Laboratory of the U.S. Fish and Wildlife Service, which keeps records of banding and recapture, a Downy Woodpecker was caught 11 years and 11 months after its first capture. Downys, like other small birds, have a median life span that is much shorter than the maximum due to high mortality in the first year of life.

If a Downy Woodpecker survives the winter, it will prepare for nesting the spring following its birth. Downy Woodpeckers nest in cavities of trees without any significant lining within. Broods generally contain 3-6 eggs, though likely, only one or two of the young will survive to the next year. After 12 days of incubation, the helpless young hatch. Unlike humans, which take years to raise, the young leave the nest only three weeks after birth. Between hatching and fledging, the parents must bring their rapidly growing young plenty of food, a job which taxes the parents severely. In most areas, parents only raise one brood per year, though there is evidence that they may raise two in the southern portions of their range, where food is available for a longer time during the spring and summer.

Range/Habitat

Downy Woodpeckers are found throughout the United States with the exception of Hawaii and parts of Texas, New Mexico, Arizona, Nevada, California, and Alaska. They are found year-round throughout this range, though, like many year-round resident birds, they may change the areas that they frequent, thus seeming to appear and disappear with the change of seasons.

Downy Woodpeckers prefer open deciduous forests, although they frequent a variety of habitats including parks and back yards. While some bird species have been negatively impacted by the fragmentation of forests or other habitat due to suburban sprawl and rural development, Downy Woodpeckers seem to be unaffected and even thrive in such areas.

Behavior

The Downy call is a sharp “pik” and song a harsh rattle. Drumming, one of the unique characteristics of woodpeckers, is both functional and a way to defend territory. While drumming is needed to create a nesting cavity or find insects under heavy bark, male woodpeckers also drum to establish a territory and maintain dominance afterwards. Woodpeckers have a shock-absorbing system in their heads that prevents their brains from slamming into their skull. Additionally, their skulls are heavier than most birds’ to withstand the repeated impact.

Ecosystem Role/Threats

Downy Woodpeckers are preyed upon by the American Kestrel, the Sharp-shinned Hawk, and the Cooper’s Hawk. Downys can be captured while in flight. Black rat snakes often prey on Downy eggs and nestlings, as do flying, red, and eastern grey squirrels. The narrow entrance to the Downy Woodpecker’s nest protects both the adults and the young from practically all predators except snakes.

Downy Woodpeckers do well in early second-growth forests, where there are more open stands of trees than in older forests. While not specifically studied at Shenandoah, there are many openings in the forest communities caused by ice storms, blow-downs from hurricanes and other severe storms, as well as tree mortality from insects and disease all of which could provide ideal habitat for Downy Woodpeckers. Overall, Downy Woodpecker populations are stable in North America, and in Canada with some increased numbers in the last 20 to 30 years.

The Downy consumes enormous numbers of insects. More than 75 percent of the bird’s diet consists of insects, a large portion of which include wood-boring beetles and other insects that affect the economy. For example, one study has shown that Downy Woodpeckers reduced the overwintering population of codling moths, a major threat to apple orchards and other fruit-growing operations, by 52 percent. This said, timber harvest and fruit production are not concerns within ShenandoahNational Park. However, other studies have shown that Downys help suppress bark beetle infestations. During the 1950s and 1960s, the Downy Woodpecker in eastern North America fed extensively on the elm bark beetle, which was responsible for dispersing Dutch elm disease. Infestations of non-native insects and disease are a significant concern at the park.

Loss of forested areas adjacent to the park seems to be the most significant issue for Downy Woodpeckers although they seem to be quite adaptable and are able to survive in non-forested areas.

Diet

While suet is a common food source for many suburban Downys, in the wild they feed on insects and grubs which they find under bark, on plant stems, and in galls of trees. A much smaller part of their diet is composed of fruit and seeds. Downy woodpeckers are one of the few woodpecker species that will come to a feeder, most often for suet.

 

Resources

"Downy Woodpecker,” All About Birds, Cornell Lab of Ornithology
Patuxent Bird Identification Infocenter, Patuxent Wildlife Research Center
Longevity Records of North American Birds, USGS Patuxent Wildlife Research Center