When we moved back to Arizona in the fall of 1984, after a three year hiatus, I was not keeping a state list and didn't have much interest in starting one. Our only birding focus until then had been seeking new birds to add to our life list. Pat Beall, my birding mentor, chided me about being "just a lister" and not a bird student. She pointed out, correctly, that a state list would enhance my understanding of geographical and seasonal distributions of regional birds, thereby increasing my enjoyment of birding in general.
By late winter she had made me a chronological list of the migrants amongst Arizona's special species, species found only here or more easily here than in any other state. Atop the list was Gray Hawk, which Pat knew would be the first arrival. Not only was I not excited but I was a bit skeptical. We had already seen Gray Hawks in the lower Rio Grande Valley of Texas the previous winter, and the dates she had given me, third weekend in March, seemed much too early to this uneducated Arizona birder.
The third weekend in March blew in cold and damp. Wrightson and Hopkins were covered with snow and the gravel road along the west side of the Nature Conservancy's Patagonia-Sonoita Creek Preserve was slushy and slick. Parked on a shoulder of the road just past the south ford, we shivered through lunch while I muttered imprecations about Pat and the Gray Hawks, the latter obviously still down in balmy Mexico.
As I rolled down my window to relieve the interior fog-up, we heard a high, piercing whistle. A Gray Hawk flew directly over us and landed on a thick horizontal cottonwood bough, silhouetted against the gray, misty sky. A moment later a second Gray Hawk, screaming, also flew directly over us and landed ... on top of the first one. I reached for pencil and paper and on the spot started two lists which I still keep religiously an Arizona state list and a "seen copulating" list. Thanks, Pat.
Gray Hawk, Buteo nitidus, is widespread and common in the tropics. North of the border, though it has been recorded in the extreme southwestern corner of New Mexico and in Big Bend National Park, it is reliably found only in the southern mountains of our state, from mid-March through early October, and in extreme south Texas where a few pairs are sedentary. Arizona's population has been guesstimated at fifty pairs.
For nesting, Arizona's Gray Hawks require large, mature cottonwoods, or sometimes sycamores, in proximity to mesquite or dense brush. They are thus confined primarily to permanent streams, such as the San Pedro and the Santa Cruz rivers, or to large, permanent ponds. The nests are typically near the tops of the tallest trees in a grove and virtually invisible because of fresh greenery added each spring. Adult birds, however, are very noisy around the nest, and a birder stumbling into the vicinity will be apprised by the high-pitched, drawn out screams. Two, but sometimes three eggs, is a typical clutch.
Until well into the last century (remember that's the 1900s now!), there was debate about Gray Hawk taxonomy. Originally thought to be accipiters, which they closely resemble in flight jizz and hunting style, Gray Hawk still bears the name Mexican Goshawk in parts of the tropics. One of our smallest buteos, with wings relatively short and tail relatively long for this family of soarers, they fly with rapid, shallow wingbeats and easily slip through dense cover in prey pursuit. Much of their diet consists of tree lizards snatched from boughs with their talons(!), but they will also take small birds, small mammals, and insects.
Along Sonoita Creek, though they are usually heard in the preserve, Gray Hawks are most easily seen by driving the highway between Patagonia and Nogales. They are often heard at The Rest Area, but more easily seen at the clubhouse pond in Kino Springs a few miles south. Other well documented locations include Arivaca Cienega just east of Arivaca, riparian areas of Buenos Aires National Wildlife Refuge west of Arivaca, including the newly opened Brown Canyon, the trails emanating from the San Pedro House east of Sierra Vista, and the lower San Pedro around Dudleyville.
If you decide to go for Gray Hawks this year, I'd suggest going right now or waiting until late summer. In early spring before the cottonwoods green up entirely it is easier to see pairs involved in nest remodeling, and you also have a chance to observe courtship flights. Gray Hawks are accomplished aerialists and in breeding season pairs may be seen circling together nearly out of sight before plunging together into stunning dives. In late summer numbers are augmented by beautiful brown and cream immatures, a subject for a future photo quiz.
And I would suggest this year, the sooner the better. With only fifty pairs in the state you should go before the San Pedro and the Santa Cruz succumb along with their giant old cottonwoods to the four horsemen of Arizona's riparian apocalypse: livestock grazing, water table depletion, woodcutting, and urban encroachment, and the zany lack of concern by our state and local officials.
We've been back to Santa Ana and Bentsen in Texas several times since 1984, but have yet to see another Gray Hawk there. Here they are still reliable, still somewhat protected, still marking their calendars, our calendars third weekend in March, guaranteed.