HawkWatch Discovers Owl Migration in Manzanos

By John DeLong

A typical visit to a HawkWatch migration site involves watching hawks during the day and sleeping from sunset to sunrise. However, when the hawks--and the hawkwatchers--are roosting, many other birds, such as Flammulated Owls, are awake and moving about. This past fall in the Manzano Mountains of New Mexico, we stayed up late and discovered that not only are these owls present in the area, but they appear to be moving through the site en masse.

Some natural history

The Flammulated Owl, or "flammy" for short, is a small bird (half the size of a male Sharp-shinned Hawk) that lives in montane woodlands throughout much of western North America. Flammies start to disperse in August, but we don’t know much about what they do in the fall. Range maps in any readily available birding book indicate that flammies winter in southern Mexico. Because of this, their status as neotropical migrants is generally accepted, yet flammy migration is poorly understood at best. To our knowledge, no one has ever seen a flammy migrate or obtained a non-breeding season banding recovery. Conservation concern about this species is high, evidenced by the flammy’s inclusion on the Partners in Flight priority bird species watchlist.

HawkWatch’s new owl research

HawkWatch recently began researching flammy movements, and our results will help clarify the migratory status and behavior of this species. The Flammulated Owl Migration Project began with an exploratory banding effort conducted in fall 1999 at the Manzano HawkWatch site. Our goal was to determine if any owls were in the area and if we could capture them. To find out, we placed a tape recording of the flammy call at the forest edge near camp and put a mist-net up next to the tape player. We retreated for a half-hour, and upon our return we discovered that the technique worked – a tiny red-brown owl was hanging in the mist net! We tried banding on a few additional nights that year and captured 7 owls total.

Armed with the knowledge that it could be done, in September and October of 2000 we set up a more extensive netting array around the meadow near Capilla Peak. In 26 nights of netting, we captured 94 Flammulated Owls (a single-season record for North America!) and 19 Northern Saw-whet Owls. Each captured owl was banded, measured, and released. Most visitors got their first or best looks at the 50-60 g flammies, and those who came in October usually got to see Northern Saw-whet Owls, too. From the data we gather over the next few years, we hope to publish a number of peer-reviewed papers on migration behavior, flight dynamics, and criteria for determining age and sex of these birds. We also hope to band enough birds to eventually obtain band recoveries that can tell us where these birds actually winter.

Ambitious Plans for 2001

In the fall of 2001, we will operate the first full-time season of the Flammulated Owl Migration Project. Our two primary goals for 2001 are to better estimate the magnitude of the movement of owls through the area and to evaluate the impact of the lunar cycle on the flight. We hope to answer these questions using a combination of mist-netting and radar observations of passing birds. The project will be running most nights throughout September and October, and visitors are always welcome. I encourage anyone visiting the site to see the hawks to camp overnight for the chance to see the mist-netting process in action and to release one of these splendid raptors.

HWI would like to thank the following project sponsors/volunteers: US Forest Service Region 3, Cibola National Forest, Public Service Company of New Mexico, New Mexico Ornithological Society, Night Owl Optics, New Mexico Coffee Company, Dan Battaglia, Bruce Casler, Anne Condon, Sarah Hamilton, Jessie Jewell, Bob Schwaller, Mark Vekasy, and the Manzano day crew. If you are interested in supporting this project in 2001, please consider purchasing a project t-shirt (see p. 15), volunteering time, or making a donation of cash, propane lantern, cots, canvas wall tent, or wood stove. Please contact John DeLong at (505) 247-9632 or jdelong@peoplepc.com if you would like to help or visit. Thanks!!