DeStefano, S., and C. M. Webster. 2012. Distribution and habitat of greater roadrunners in urban and suburban Arizona. Studies in Avian Biology 45:155– 166.
Abstract. Greater Roadrunners (Geococcyx californianus) are widespread throughout arid regions of the southwestern United States. As a large predatory bird, roadrunners require large home ranges and their relatively low densities and secretive nature make surveys and observations a challenge. However, roadrunners are among the most well-known and charismatic avian species in the Southwest and draw much attention from residents and visitors. Distribution of roadrunners and habitat features of importance to roadrunners in urban and suburban environments have not been described, and it is not known how development may affect roadrunner populations. Although roadrunners are occasionally seen in southwestern cities, urbanization may eliminate local populations. We used public sighting information to document roadrunner locations in metropolitan Tucson, Arizona. We explored and, when possible, evaluated the types of biases (e.g., species misidentification, erroneous information, non-response and self-selection biases) inherent in public information surveys. We also employed researcher-based, randomly distributed surveys to examine roadrunner distribution and habitat use, to estimate the amount of survey effort required to detect a low-density elusive species like roadrunners, and to establish a sample of sightings based on random sampling. We received 1,449 reports of roadrunner sightings from the public and saw 52 roadrunners on 281 researcher-based surveys. The general pattern of distribution of roadrunner sightings in Tucson was similar from both public and researcher surveys, forming a broad band around the edge of Tucson with few or no sightings in the city center. Tucson residents reported seeing roadrunners most often in areas with housing densities of 2.5-7.5 residences per ha (RHA) and non-native vegetation, and less often than expected in areas with washes, natural open space, native vegetation, graded vacant land, and housing densities of 7.5-15 RHA. In contrast, during our random surveys we found roadrunners closer to washes and areas with housing densities of 7.5¬¬-15 RHA, indicating that roadrunners used these land cover-types more frequently than was reported from the public. In general, however, roadrunners used a variety of urban and suburban environments and could be seen almost anywhere in the city except for areas with the highest housing densities (>15 RHA). Public survey information provided a great deal of usable data quickly and inexpensively but reflected where people saw and reported roadrunners. Interpretations of relative abundance or habitat preference need to be made cautiously.