Yellow-bellied sapsucker

French disease name: Pic maculé
Pathogen name: Sphyrapicus varius L.
Class: Piciformes

Distribution

Eastern Canada

Damage, symptoms and biology

Yellow-bellied sapsuckers attack only living trees. In forested areas they have been observed feeding on a wide variety of deciduous and coniferous species. In prairie and urban areas where trees are planted for ornamental and shelterbelt purposes, they seem to prefer birches, blue spruce, Scots pine, and Siberian elm.

The adult birds cause damage by pecking horizontal rows of regularly spaced, small, oval-to-squarish holes through the bark to the sapwood. Unlike other woodpeckers, sapsuckers do not drill these holes in search of grubs or worms on which to feed. Instead, the birds use their short, brush-like tongues to drink the sap that oozes into the holes. They also eat the outer wood layers. As one row of holes becomes dry, another row is drilled, and so on. Rows of holes may extend for some distance up the trunk and heavier branches a damaged tree. Injury is usually most pronounced in the spring and early summer when sap pressure is greatest.

Damage varies considerably, depending on the persistence of attack. Lightly attacked trees usually make a complete recovery. On the other hand, branches girdled with several rows of holes are often permanently damaged, and smaller trees or tops of trees may be killed by severe attack in several successive years. Harmful insects and disease organisms may enter the tree by way of these holes, resulting in secondary damage. The characteristic holes made by sapsuckers and the subsequent staining or discoloration of the wood can be recognized many years after the attack.

The yellow-bellied sapsucker is a small (20-23 cm) migratory member of the woodpecker family that is present throughout the summer. Although colors vary between individual birds, sapsuckers are readily identified by a long white stripe down their closed wings that is visible when they are perched on a tree. The mature male has a red crown and throat, both bordered with black, and the mature female has a smaller red crown and a white throat. Both have white bands above and below the eye extending onto the neck, a black patch on the breast, and a yellowish white abdomen. Young birds in juvenile plumage appear brown and have no black breast patch, but like the adults they have the long white wing markings.

Sapsuckers usually nest in holes well above the ground in the heartwood of dead or partly dead trees located within easy flying distance of their selected feeding ground. Three to seven white eggs are laid per nest. Each pair of birds establishes a territory onto which other sapsuckers do not trespass, and if the territory is productive a pair may return year after year to the same location. About 50% of the sapsucker's diet is composed of sap and sapwood; the other 50% consists of wild berries and fruits, and the flying insects attracted to the sap exuding from the holes drilled in the trees.

Other information

The yellow-bellied sapsucker, like most other birds, is protected under The Migratory Birds Convention Act. It may not be killed or captured or its eggs destroyed. Serious damage can be prevented to some extent by placing noisemakers and frightening devices (flutters) in affected trees. Another effective treatment consists of wrapping the damaged areas of individual trees with strips of burlap or other protective material and leaving the wrapping in place from April until late summer when the birds are most active.