Beak overgrowth in a Hairy Woodpecker and a Red-breasted Nuthatch

Recently photos showing a marked overgrowth of the beak in a Hairy Woodpecker and in a Red-breasted Nuthatch were submitted to CWHC-Québec.

The two birds were photographed at two different feeders in the Laurentians region (north of Montreal). Even if this type of presentation, which is quite unusual in Quebec, is non-specific, it shared some similarities with birds affected by a syndrome well described in northwestern North America in different species of birds, including chickadees, crows, woodpeckers and nuthatches. This syndrome, known under the name of “Avian keratin disorder”, is believed to be caused by a virus (Poecivirus) which increases the rate of growth of keratin of the birds’ beak. Although the vast majority of confirmed cases are from Alaska, a recent publication reports a case in a Blackpoll Warbler from Maine. This suggests that this virus is probably more widely distributed in North America than we think. Obviously, the confirmation that these beak anomalies are indeed associated with this viral infection would necessitate that the affected birds being analyzed. Until then, it will be interesting to properly document the occurrence of this clinical presentation in order to better characterize this phenomenon.

You can report birds found dead, sick or with abnormalities to the Canadian Wildlife Health Cooperative. Find the nearest regional centre at: http://www.cwhc-rcsf.ca/

Stephane Lair

CWHC – Quebec