I have been down in Tubac, Arizona this past week in the capacity of a Swarovski Optik vendor at the annual Tubac Hawk Watch event. Tubac is a very small town in southern Arizona, approximately 20 miles from the Mexican border, right off the I-19.
The hawk watch is held at the Ronald R. Morriss County Park, directly adjacent to the Santa Cruz River. The headwaters for the Santa Cruz River begin in the San Rafael Valley southeast of Patagonia, Arizona. The river initially flows south into Mexico before gradually turn west then north where it flows back into Arizona. The river provides a lush riparian corridor that stretches for miles and miles.
The Tubac hawk watch site is operated by HawkWatch International. This organization has been conducting raptor migration research in the American west for over 36 years, including an annual fall hawk watch event at the Grand Canyon. Tubac became an official hawk watch location in 2012, and draws spectators from all over the country.
The primary purpose of monitoring raptor migration is to track long-term population trends, which helps to identify conservation needs of diurnal raptor populations in North America. Birds of prey migrate during the day, hence the expression “diurnal,” meaning they are active during the day. This is in contrast to nocturnal birds of prey—such as owls—which are active at night.
Most birds of prey have broad wings for soaring, and rely on thermals (warm columns of rising air) to provide the lift they need to soar effortlessly for hours on end. Without thermals and updrafts, birds of prey would have to expend a tremendous amount of energy flapping their wings to maintain their altitude.
Each year, hundreds of thousands of individual birds of prey move north and south, spring and fall, between the United States and the tropics. As spring migration gets underway, countless birds of prey start making their way back to their summer breeding grounds. The hawk watch counts vultures, falcons, hawks, eagles, osprey and other bird of prey species.
This past week, I have personally observed the following birds of prey species at the Tubac hawk watch event: black and turkey vultures, golden eagle, osprey, peregrine falcon, American kestrel, sharp-shinned hawk, Cooper’s hawk, red-tailed hawk, zone-tailed hawk, black hawk and short-tailed hawk. Twelve different species!
A typical hawk watch day includes a lot of sitting and a lot of waiting. Early morning hours are slow, as it’s still too cold. About mid-morning, as thermals develop, birds of prey take flight. Initially, the birds passing over the count area are lower in altitude. However, as the day progresses and it gets warmer, the birds passing over fly at increasingly higher altitudes.
By mid-day, the number of birds passing over drops off significantly. Those birds that are still on the move become increasingly more difficult to see, as they are flying so high they are literally a mere speck in the sky.
Many people participating in the hawk watch bring—in addition to their binoculars—a spotting scope. More magnification is the key to identifying the birds when they are so high in the sky.
Afternoons tend to be fairly slow, but a small trickle of birds still pass over the count area for hours. Around 5:00 p.m., when the temperatures begin to drop off and thermals become weaker, migrating birds of prey tend to settle down for the balance of the day.
If you’ve never participated in a hawk watch event, I encourage you to consider attending one for a day or two. I personally have thoroughly enjoyed being a part of the Tubac event.
Until next week, Happy Birding!
Eric Moore is the owner of The Lookout, in Prescott, where you will find a Hallmark Gold Crown Store, wild bird products, and Vortex and Swarovski optics. Eric has been an avid birder for over 55 years. Eric can be contacted at eric@thelookoutaz.com.
