Tuesday, January 5, 2016

Native Species Profile - Downy Woodpecker

Visit a woodland in Mid-Michigan during the right time of year and it is not uncommon to see six different species of woodpeckers that call the area home: the Pileated Woodpecker, Red-Bellied Woodpecker , Hairy Woodpecker, Northern Flicker, Yellow-bellied Sapsucker, and the most common of all, the Downy Woodpecker.  The Downy Woodpecker (Picoides pubescens) is the smallest woodpecker species in North America.  It typically measures 5.5 to 7 inches long and has a wingspan of 10 to 12 inches.  This small size allows it to live in a wide range of habitats across North America, being absent only in the desert Southwest and the arctic tundra.

The Downy Woodpecker is easy to identify.  They have a two-toned color scheme, with white on the underparts (chest and belly) and mostly black above.  The wings are black with white checkering.  Most of the tail feathers are black, with white feathers (with black checkering) on the outer edges of the tail.  There is a white stripe down the center of its back.  A Downy Woodpeckers head has a broad black stripe running over the top of its head, another broad black stripe that looks like a mask, and a narrower black stripe running downward from the corners of the beak.  With the exception of this stripe, the feathers at the base of the beak are white.  Males can be distinguished from females by a red patch on the back of their head - this is known as an occipital patch.  Downy Woodpeckers have a short stubby black beak.  The larger Hairy Woodpecker (P. villosus) has similar markings but is larger (8.5-10 inches long, 15-17.5 inch wingspan) and a longer beak.

Male Downy Woodpecker - note checkered wings, white back, striped face, and red occipital patch

Like most other woodpeckers, Downy Woodpeckers use their short beak as chisel to probe into dead or decaying wood for their favorite food source - insects and their larvae.  A large proportion of their diet consists of ants, beetles, and other woodboring insects.  They also consume spider and other invertebrates.  In addition, Downy Woodpeckers eat berries, seeds, and acorns.  They will rarely drink tree sap or nectar to supplement their diet.  Most of their foraging is done in trees, but they will feed on the ground.

Downy Woodpeckers are well adapted for their foraging style.  In addition to their chisel-like beak, they have a thick skull to cushion their skull when they use their beak to hammer at trees, and a long barbed tongue used to pull insects from tunnels in the wood.  Unlike perching birds (such as sparrows), the toes on woodpeckers are arranged with two pointing forward and two pointing backward.  This adaptation, known as zygodactylism, allows the woodpecker to climb easily up the trunks of trees and even hang upside down on branches that are beyond vertical.  Their stiff tail feathers are pushed against the tree's surface, acting as a counterbalance.

A Downy Woodpecker searches for insects and other invertebrates on a sumac tree

Downy Woodpeckers are a cavity nesting bird.  Because of their strong beak, they are able to excavate their own nesting cavities in decaying trees.  They typically use these homes for one nesting season before abandoning them.  These abandoned cavities provide nesting sites for other small birds such as bluebirds and swallows that are unable to excavate their own cavities.  Rarely, Downy Woodpeckers will nest in man-made nest boxes.  It attempting to attract woodpeckers to nest boxes, the box should be packed with woodshaving so that the woodpeckers can "excavate" the box tot heir satisfaction.

A female Downy Woodpecker works on a nesting cavity - note the lack of red on the back of the head

Basic Information

Downy Woodpecker
Picoides pubescens

Size:  5 ½-7” long,
          10-12” wingspan
Habitat:  woodlands (mainly deciduous), fencerows, wetlands, suburban areas
Eats:  insects, spiders, insect and spider eggs, other invertebrates, berries, seeds, acorns, rarely tree sap and nectar
Nest:  in tree cavity, rarely in a nesting box

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