Downy Woodpecker – Nome’s spunky winter woodpecker
People are sometimes surprised to learn that there are woodpeckers around Nome and even more surprised to see one. The smallest of North American woodpeckers, a small number of downy woodpeckers are regular year-round residents in forested areas of the Seward Peninsula
Like black-capped chickadees featured last week, downy woodpeckers usually stay throughout the year in one area, but a few move out of their breeding territory to a different location and habitat for the winter. This behavior brings some woodpeckers from the forests to the east into willow thickets around Nome and other shrubby areas where they are not seen during the summer.
For most of our 26 years living at Banner Creek, a single or occasionally a pair of downy woodpeckers has joined the chickadees at our seed and suet feeders for the winter. They climb all over the cedar siding on our house, picking insect pupae from the cracks and occasionally drum on our walls.
This winter it is a male downy that comes each morning and evening at first and last light and occasionally in between, but not nearly as often as the chickadees. He flies in fast with characteristic undulating flight as he alternately beats his wings and glides with wings tucked along his sides. Often he goes out of his way to chase the chickadees even if they are nowhere near “his” suet feeder.
Like the chickadees, the woodpecker forages very actively. He moves quickly up vertical willow and cottonwood trunks and over the surface of branches and twigs, sometimes hanging upside down. He searches for insect eggs and pupae as he goes, pausing to tap and probe into bark, or occasionally to scan for predators, cocking his head one way, then another.
Woodpeckers make up an interesting family of birds that share some unique characteristics, evolved for their tree-climbing lives, including stiff tail feathers that woodpeckers use to brace themselves as they move up and down tree trunks.
Most songbirds have three toes pointing forward and one toe pointing to the back. Woodpeckers have a different toe arrangement called zygodactyl feet. Their first and forth toes point towards the back and the middle two toes point forward, giving them a strong opposable grip for climbing and hanging.
Strong head and neck muscles allow woodpeckers to drill and probe for food and excavate nest cavities and roosts. A thickened skull provides shock absorption, protecting the brain from the impact of drilling into wood. Typically, woodpecker bills are stout and chisel-shaped, but the downy woodpecker’s bill is less so than bills of other woodpecker species.
Downy woodpeckers have sharply pointed bills for working close to the surface of a tree. They pick open insect tunnels and probe and extract insect eggs, larvae and pupae from beneath the bark or from branches and leaves.
Long, barbed tongues with sticky saliva maximize capture of insects when probing crannies and excavations. When retracted, the tongue wraps around the back of the head between the skin and the skull, providing extra padding for the brain when they drum or tap.
Downy woodpeckers are monogamous, but pairs tend to separate in late fall through much of the winter unless food on the breeding territory is very plentiful.
By late winter pairs reunite or new pair bonds are formed during a period of increased drumming by both sexes. Drumming is thought to serve a number of purposes, including attracting a mate, keeping in touch with an established mate and strengthening the pair bond. It may also be used to establish or defend a territory.
Once pairs are united, they remain together through the breeding season. The pair shares the task of excavating a nest cavity, usually in a dead tree or limb. The slow and deliberate tapping used to excavate a nest cavity is in contrast to the rapid, softer, almost continuous tapping used when feeding.
Typically, four to five eggs are laid and both sexes share incubation. In about 12 days the young hatch, helpless, naked and blind. The nestlings grow quickly on a diet of protein-rich insects delivered by the bill-full by both parents. In 20 to 25 days after hatching, the young fledge from the nest and remain with the parents for up to another few weeks before dispersing.
There has been little research on the ecology of woodpeckers in Alaska, but studies in the continental U.S. have uncovered a number of interesting aspects of their lives. At times, downy woodpecker pairs reduce competition with each other by foraging in different parts of their habitat. Males may feed along smaller, outer branches while the female uses larger branches and tree trunks. Studies have shown that in cold, windy conditions, the downy woodpecker’s foraging speed slows down, presumably to conserve energy.
Downy woodpeckers have been shown to have greater cold tolerance in winter than summer, with higher metabolic rates in winter, but their fat reserves do not increase seasonally.
They apparently rely on finding adequate insect prey and cavity-roosting to obtain and conserve energy during cold weather without the complex physiological adaptations evolved by chickadees.
Roost cavities are excavated in the fall, usually in a dead tree and occupied by a single woodpecker. Occasionally downy woodpeckers will create a roost cavity in the wall of a building. I would be fascinated to know where around Nome these woodpeckers roost.
Downy woodpeckers have a preference for birch, aspen and cottonwood trees of deciduous forests which probably explains why the species is uncommon in the largely coniferous spruce forests of the Seward Peninsula. This is one species that may benefit from the ongoing advance of shrubs across the region.
It is good news that nationwide, this lively little woodpecker seems to be holding its own with no overall significant upward or downward trend in numbers.