Arizona Field Ornithologist

Santa Cruz Flats Raptor Survey

Prairie Falcon - Photo by Muriel Neddermeyer


Many hawk species winter in southern Arizona, some in relatively large numbers, augmenting resident populations. Santa Cruz Flats in Pinal County is particularly noteworthy for drawing these winter visitors. Located along the basin of the Santa Cruz River, which flows northwest across the county towards the Gila River, the area encompasses approximately 350 square miles and has an average elevation of 1,700 feet. It is primarily agricultural, and fields of cotton, alfalfa, corn, and sorghum, laced with irrigation ditches, share the area with two large sod farms, several pecan groves, a dairy farm, cattle pastures, and a large cattle feed lot. Abundant rodents, thousands of wintering sparrows, and a big population of doves offer a ready food supply for raptors. Palms, cottonwoods, pines, and clumps of tamarisk and Mexican palo verde provide roosting sites for owls.


Crested Caracaras, first reported from this area in 1965, appear to be increasing. Although the numbers observed in the winter are higher than other seasons, they are seen year-round as some pairs nest in the area. A population of Black Vultures also resides at this location, although at this point its nesting sites and total numbers are not well known. Turkey Vultures, while common in summer and very numerous during migration, are rare in the winter. 


Birders often visit this area in the winter to look for raptors as well as nonraptors such as Mountain Plovers, Mountain Bluebirds, and Sagebrush Sparrows, but no systematic count of raptors had ever been made before and no part of the area is in a Christmas Bird Count circle. Annually assessing the number of raptors wintering in this area is useful for judging population trends and migratory patterns. It is with this in mind that on 21 January 2006 nine birders, organized into three teams, conducted the first tally of raptors in the area. Since then the count has become an annual activity usually held on the third Saturday of January.


For each of the first three years of the count three teams surveyed the area. In response to increased interest 34 square miles were added to the northern section of the count area in 2009, and four teams conducted the survey in slightly altered sections. Predawn owling was begun in the third year of the count. In 2016, without changing the overall survey boundaries, the area was redivided into five sections. The area covered by the survey is bounded on the south by the Pinal County-Pima County line and on the west by Trekell Road to Battaglia Road and then jogs west to Chuichu Road. The northern boundary runs along Shedd Road from Chuichu Road to Wheeler Road then jogs south to run along Baumgartner Road from Wheeler Road through a line extending from Baumgartner to I-10. The eastern boundary is Wheeler Road from Shedd Road to Baumgartner and then a diagonal line along I-10 (from where it would intersect with Baumgartner if the latter were extended east) to the Pima County line.


Naturally, such a count is approximate; some areas away from roads are not reached, and it’s possible that a few birds are counted twice. But as the data for the wintering raptor population accumulates, we are hoping long-range trends will be clearer. A summary of the first 10 years of the count can be found in Arizona Birds.


For more information, please contact the survey coordinator, Doug Jenness, d_jenness AT




If you are interested in participating in the Santa Cruz Flats Raptor Survey, Contact

Area Coordinator
Doug Jenness

Count Results


Crested Caracara - Photo Muriel Neddermeyer


Updated Saturday, April 18, 2009