Home Range and Use of Habitat of Western Yellow-Billed Cuckoos On the Middle Rio Grande, New Mexico

Abstract The western yellow-billed cuckoo (Coccyzus americanus occidentalis) is a Distinct Population Segment that has been proposed for listing under the Endangered Species Act, yet very little is known about its spatial use on the breeding grounds. We implemented a study, using radio telemetry, of home range and use of habitat for breeding cuckoos along the Middle Rio Grande in central New Mexico in 2007 and 2008. Nine of 13 cuckoos were tracked for sufficient time to generate estimates of home range. Overall size of home ranges for the 2 years was 91 ha for a minimum-convex-polygon estimate and 62 ha for a 95%-kernel-home-range estimate. Home ranges varied considerably among individuals, highlighting variability in spatial use by cuckoos. Additionally, use of habitat differed between core areas and overall home ranges, but the differences were nonsignificant. Home ranges calculated for western yellow-billed cuckoos on the Middle Rio Grande are larger than those in other southwestern riparian areas. Bas...