The remains of a mystery cavity-nester

There’s nothing as exhilarating as a discovery that poses a mystery.

In an oak woodland in Orange County, CA we recently discovered this deceased immature bird among nesting material in a fallen tree cavity.  Its long, heavy bill suggests a woodpecker, but as a rule woodpeckers use only wood chips not vegetation in their excavated cavities. One of the exceptions is the Northern Flicker.  We are unsure if that species nests in the location.

With assistance from woodpecker specialist, Stephen Shunk, author of the Peterson Reference Guide to North American Woodpeckers (pictured here), the mystery was forwarded to two of California’s renowned ornithologists, Phil Unitt Ph.D (of San Diego County Natural History Museum) and Kimball Garrett Ph.D (of Los Angeles County Natural History Museum). Unfortunately neither could be certain of the bird’s identity because of insufficient documentation of the carcass. Apparently the tip of the bill does not appear to be a strong match for the flicker, but it remains a possibility.   Cavity nesters such as other woodpeckers, nuthatches and the Ash-throated Flycatcher were ruled out.  An interesting question posed was this.  Was the baby bird a prey item brought into the cavity by an American Kestrel (also a cavity nester)?

The process taught us a few things about proper documentation, particularly the importance of photographing other bones and using an indicator of size.

To learn more about woodpeckers, we highly recommend Stephen Shunk’s beautifully illustrated book!  And we thank all three bird specialists for their assistance.