The raptor eye is specially adapted in both the gross architecture and ultrastructure for visual acuity, day/night vision and flight navigation. For this study a correlative approach utilizing light, fluorescence and scanning electron microscopy was used to investigate specific structures of the eye of Buteo jamaicensis (red-tailed hawk). The structure of the pecten oculi and retina were examin...

The Galapagos Hawk (Buteo galapagoensis) is the only diurnal resident raptor in the Galapagos Archipelago, where it exhibits a cooperatively polyandrous mating system. Before breeding, young hawks spend 3-4 years as nonterritorial floaters. Individuals in this age class are highly gregarious on the island of Santiago. Here we examine patterns in natal dispersal and ask whether they appear to de...

We tested for associations between body condition, territory ownership, and permanent parasite load of Galápagos Hawks (Buteo galapagoensis) on Isla Marchena, Galápagos. Two louse species were collected from most of the 26 hawks sampled: the amblyceran Colpocephalum turbinatum and the ischnoceran Degeeriella regalis. Nonterritorial hawks were in significantly poorer body condition than territor...

In both spring and autumn, millions of migratory birds of prey that breed mainly in North America, and overwinter mainly in South America, travel between these two continents via the Mesoamerican Land Corridor, numerically the most important raptor-migration flyway in the world. Although the flight has been well documented at migration bottlenecks in Veracruz, Mexico, and the canal region of Pa...