title: Contrasting molecular and morphological evidence for the identification of an anomalousButeo: a cautionary tale for hybrid diagnosis.
abstract: An adultButeowas found dead as a road-kill south of Sacramento, California, and was thought to represent the first state record of the eastern Red-shouldered Hawk (B. lineatus lineatus;). It is now a specimen in the Museum of Wildlife and Fisheries Biology (WFB 4816) at the University of California, Davis. We examined this specimen and found that many of its plumage characters differed from all other adult Red-shouldered Hawks examined, including nominate adults. Plumage markings and measurements were intermediate between Red-tailed Hawk (Buteo jamaicensis,sspcalurus) and Red-shouldered Hawk (sspelegans), leading us to hypothesize that the bird was a hybrid. However, mtDNA sequences and nuDNA microsatellites proved definitively that the bird was a Red-shouldered Hawk, most likely of eastern origin. This case illustrates that apparent hybrids or apparent vagrants could be individuals with anomalous phenotypes caused by rare genetic variation or novel epigenetic effects.
authors.affiliation: Harlingen, TX, United States.
authors.forename: William S
authors.initials: WS
authors.lastname: Clark
authors.affiliation: Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, NY, United States.
authors.forename: Spencer C
authors.initials: SC
authors.lastname: Galen
authors.affiliation: Department of Animal Science, University of California, Davis, CA, United States.
authors.forename: Joshua M
authors.initials: JM
authors.lastname: Hull
authors.affiliation: Department of Animal Science, University of California, Davis, CA, United States.
authors.forename: Megan A
authors.initials: MA
authors.lastname: Mayo
authors.affiliation: Museum of Southwestern Biology and Department of Biology, University of New Mexico, Albuquerque, NM, United States.
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Witt
keywords: DNA; Hybrid; Morphology; Phenology; Specimen; Unusual plumage