Electrocution of raptors on poles supporting overhead electric lines is a cause of concern in the United States. Techniques for modifying (i.e., retrofitting) potentially lethal poles to reduce electrocutions have been applied in rural areas to poles most likely to be used by raptors. However, raptors also live in urban areas, and criteria for selecting poles to retrofit in towns and cities may differ from those in rural areas. We assessed the effectiveness of using nest sites of Harris's Hawks (Parabuteo unicinctus) in Tucson, Arizona, U.S.A., as a means to focus proactive efforts to retrofit potentially lethal poles. Specifically, we investigated: (1) whether poles close to Harris's Hawk nests were more likely to cause electrocutions than more distant poles with the same configuration; and (2) whether retrofitting poles within 300 m of nests reduced electrocutions in treated areas. We assessed the number of electrocutions before and after retrofitting by searching for electrocuted hawks at a sample of poles. In 2003, we found 23 electrocuted Harris's Hawks within 300 m of nests. The proportion of poles that electrocuted a juvenile Harris's Hawk remained relatively constant from 0 to 300 m from nests. Poles 201–300 m from nests were more likely to electrocute subadult and adult hawks than were poles <200 m from nests. Prior to retrofitting poles, we detected 1.4 electrocutions per monitored nest. After about half of the potentially lethal poles within 300 m of nests were retrofitted, we detected 0.2 electrocutions per nest. For Harris's Hawks in Tucson, risk of electrocution was at least partially related to the proximity of nests to potentially lethal poles. This relationship also may hold for other medium- to large-bodied raptors nesting in urban environments. We recommend that all potentially lethal poles within 300 m of the nests of urban-nesting raptors be retrofitted through the addition of insulation, or through increased spacing between conductors.

The Spectacled Owl (Pulsatrix perspicillata) seems to be uncommon near the southern limit of the species' range. Here, we report new records for the Spectacled Owl, identify the subspecies, and examine the spatial distribution of records in the southern part of the species' range. We made 50 sightings of at least two adults and six juveniles over 3 yr in a gallery-forest habitat within Estancia Guaycolec, Formosa, Argentina (25°58′S, 58°10′W). We compared the external morphology of the adults found in Estancia Guaycolec with those of the P. p. boliviana, P. p. pulsatrix, and P. p. perspicillata subspecies, and found great similarity with the features of P. p. perspicillata. We also analyzed the vocalizations of an adult recorded at Estancia Guaycolec and found that its calls accelerated towards the end, as has been reported for P. p. perspicillata. Spatial analysis of records from the southern region of the Spectacled Owl's range showed an alignment of the records from the Chaco region alongside the Paraguay River. The gallery forests along the banks of the Paraguay River and its tributaries seem to provide P. p. perspicillata with a continuum of suitable habitats, extending its range southward. Conservation of this riparian corridor is likely crucial to maintain the current distribution of the species.

Barn Owls (Tyto alba) have been considered a useful tool for estimating extinct and extant distributions of small mammals by the analysis of their diets. To test Barn Owlś' sensitivity to environmental changes, we analyzed the trophic ecology of these owls in northern Argentine Patagonia, a region characterized by a marked west-east vegetative gradient. We based our study on new and published information on diets in 15 localities along this gradient, from the Andes to the Atlantic Ocean. We analyzed number of mammalian prey items, food niche breadth, and mean weight of prey. We used Barn Owls' food habits to detect changes in the local composition of prey species, by means of correspondence and cluster analysis. Our results confirmed Barn Owls as small-mammal specialists (up to 99% of their total prey). The number of mammalian prey species and the mean weight of prey decreased from west to east, and food niche breadth was not correlated with longitude. Statistical analyses yielded an ordination of localities that corresponded to changes in vegetation and in small-mammal assemblages. Our results in northern Patagonia showed that prey selection along a vegetative gradient was associated with the rodent assemblages in each vegetation type. This suggests that the use of Barn Owl pellets is appropriate for study of the distribution of small mammals.

The fossil eagle Aquila borrasi Arredondo from the Quaternary of Cuba is redescribed and transferred to the genus Buteogallus Lesson, in which it represents a gigantic version (ca. 33% larger) of the morphology present in the living Great Black-Hawk B. urubitinga (Gmelin). Buteogallus borrasi differs from the other large fossil accipitrids recorded in the West Indies, Amplibuteo woodwardi, Gigantohierax suarezi, and Titanohierax gloveralleni, in being smaller, less robust, and with proportionately slender hindlimb elements, especially the tarsometatarsus. Although now known with certainty only from Cuba, B. borrasi may have had a wider distribution in the West Indies and perhaps even mainland North America.

We measured the characteristics of trees and sites of 14 Northern Goshawk (Accipiter gentilis) and 14 Eurasian Sparrowhawk (Accipiter nisus) nests in the Ishikari Plain of Hokkaido, Japan, where their nesting habitats were fragmented into small woodlots. We also randomly located 25 plots (0.033 ha each) in unused woodlots to compare differences between nest and random sites. Goshawks nested in a variety of trees and diameters at breast height (dbh) of nest trees were significantly larger than the mean values for all trees in the nest sites, and were similar to the largest trees in these sites. The heights of nest trees were significantly larger than the mean values of all trees in the nest sites. Goshawks nested in a variety of forest types, in proportion to their availability. The dbh and tree heights of sparrowhawk nest trees were significantly larger than the mean values of all trees in the nest sites, and were significantly smaller than the largest trees in these sites. Sparrowhawks nested only in evergreen conifers, and their nests were more likely to occur in evergreen coniferous forests than in other forest types. Diameters of nest trees were larger for goshawks than sparrowhawks, but the tree density was higher for sparrowhawks. Goshawks and sparrowhawks nesting sites were further from human habitation than random sites, but averaged only 247 and 229 m from houses, respectively.

Winter diets of the western Burrowing Owl (Athene cunicularia hypugaea) are little known. We determined the diet of western Burrowing Owls wintering in southern Texas by analyzing the contents of 182 pellets collected over four winters (1999–2000, 2001–2002, 2002–2003, and 2003–2004) in three habitat types (agricultural, mainland grassland, and barrier island). Remains of a total of 7476 prey items were recovered, 98% of which were arthropods. Gryllidae (crickets) formed the largest component (50%) of the prey, followed by lepidopteran larvae (13%), beetles (8%), spiders (7%), and earwigs (6%). Although vertebrates, primarily small mammals and birds, represented only 2% of prey items by number, they represented most (71%) of the biomass. Northern pygmy mice (Baiomys taylori) and fulvous harvest mice (Reithrodontomys fulvescens) were the two most frequently consumed vertebrate species. In all habitats, arthropods, especially orthopterans, were the primary prey item by number, whereas vertebrates, primarily small mammals, were the most important by biomass. Greater consumption of arthropods by Burrowing Owls in agricultural areas may be a factor contributing to owl use of these highly altered environments.