Merlin. Photo: Muriel Neddermeyer.
Many raptor species winter in southern Arizona, adding to resident populations. The agricultural lands of the Santa Cruz Flats in Pinal County are noteworthy for attracting 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. Abundant rodents, thousands of wintering sparrows, and a big population of doves offer a ready food supply for raptors.
Since 2006, volunteers have joined in counting raptors on the third Saturday in January. This survey assesses the number of wintering raptors and establishes a useful baseline for monitoring winter raptor population trends and for evaluating future plans that could impact the habitat and raptors at this location. A summary of the first 15 years of the count can be found in Arizona Birds.