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Urbanization is a process of environmental change which reduces and fragments the original habitat and creates new pressures, conditions, and resources for the species. The urban areas act as an ecological filter, which may exclude species, while others can colonize and thrive in cities, generating a process of biotic homogenization. As top predators, the changes in prey community composition could affect the diet of raptors. However, this effect has been understudied. In this study we compiled information about the frequency of prey consumed by Cooper's Hawk, Common Black Hawk, Roadside Hawk and Gray Hawk using two sources of information: (1) data extracted from photographs available on citizen science platforms and (2) a search of scientific literature. Using these data, we compared the diet composition, the proportion of prey consumed and the trophic niche breadth by four species of raptor in urban and non-urban areas. Additionally, we evaluated whether the variability in frequency of predation records by raptors was associated to the type of prey or their breeding season. Our results indicate that the raptors studied consumed at least 91 prey species in Mexico. Most records of predation by Common Black Hawk, Roadside Hawk, and Gray Hawk occurred in non-urban areas. On the contrary, most records of predation by Cooper's hawks occurred within urban areas. There was no statistical difference in the richness of prey consumed by Cooper's Hawk and Gray Hawk between urban and non-urban areas. In contrast, fewer prey types were consumed by Common Black Hawk and Roadside Hawk in urban areas than in non-urban areas. The proportion of prey types consumed in urban and non-urban areas was significantly different for Cooper's Hawk, Roadside Hawk and Gray Hawk. Conversely, the proportion of prey types consumed by Common Black Hawk's was similar in urban and non-urban areas. The four raptors studied increased the proportion of birds consumed in urban areas by between 2% and 36%, regardless of their preference for a specific type of prey. The trophic niche breadth of raptors was broader in urban areas than in non-urban areas, except for Cooper's Hawk, which had a narrow trophic niche breadth in urban areas than in non-urban areas. The temporal variation in the frequency of predation records was influenced by differential factors such as the breeding season, the type of prey consumed, and the utilization patterns of citizen science platforms. Our results demonstrate that the four raptors studied increased the proportion of bird consumption in urban areas. This shift in raptors' diets could be linked to the increased prevalence of diseases transmitted by feeding on infected birds in urban areas. This emphasizes the importance of conducting research to assess the prevalence and transmission rates of diseases that could threaten the conservation of birds and raptors in urban areas.

Despite the interest of resource managers and conservationists in the status of Common Black-Hawk (Buteogallus anthracinus) populations in the southwestern United States, little is known about their nesting success and habitat requirements. Because such information is essential for effective population and habitat management, I examined the nesting success and nest-site selection of Common Black-Hawks in southwestern New Mexico during 2000 and 2001. Of the 37 nesting attempts in 21 territories, ≥ 1 young fledged from 25 nests (68%). Comparison of nest-sites and nonused sites suggested that breeding Common Black-Hawks selected nest-sites in areas with a sparser and shorter subcanopy tree layer and in trees with a smaller trunk diameter and a greater minimum crown diameter. These differences appear to be related to variation in forest ages within territories, with nonused sites having fewerm but older, canopy trees than nest-sites. Sites with younger, smaller subcanopy trees may provide forest structure for more effective foraging, whereas the characteristics of younger, smaller tree canopies may reduce the risk of nest predation or offer more protection from inclement weather. Due to the limited range of this species in the southwestern United States, efforts to encourage the establishment and maturation of riparian forests in Common Black-Hawk breeding areas could be important in sustaining available nesting habitat and, in turn, maintaining or expanding current population levels. /// Aunque existe interés de parte de profesionales en manejo de recursos y conservacionistas en el estatus de las problaciones de Buteogallus anthracinus en el sudoeste de los Estados Unidos, poco se conoce sobre su éxito de anidamiento y requerimientos de hábitat. Por la razón que esta información es esencial para el éxito del manejo poblacional y del hábitat para esta especie, examiné el éxito de anidamiento y la selección del lugar de anidamiento de Buteogallus anthracinus en el sudeste del estado de Nueva México durante el 2000 y el 2001. De los 37 intentos de anidamiento en 21 territorios, ≥1 de los polluelos volaron de 25 nidos (68%). Una comparación entre lugares donde se ubicaban los nidos y sitios no utilizados para anidar indica que individuos seleccionaron lugares para anidar en áreas con una menor cobertura y una menor altira del sub-dosel. Adicionalmentre, los nidos fueron ubicados en árboles con un menor diámetro del tronco y con un mayor diámetro mínimo de la corona. Estas diferencias parecen ser relacionadas a la variación en la edad del bosque dentro de los territorios, con sitios no utilizados caracterizados por un número menor de árboles del dosel pero las cuales tienen una edad mayor que los árboles del dosel en los sitios donde se ubicaron los nidos. Sitios con árboles en el sub-dosel de menor edad y de menor tamaño podrían proveer la estructura del bosque necesaria para un forrajeo mas efectivo, mientras que las características de las coronas de los árboles de menor edad en la cual se encuentra el nido podrían reducir el riesgo de la depredación del nido o proveer mas protección de mal tiempo. Dado el rango limitado de esta especie en el sudeste de los Estados Unidos, los esfuerzos para animar el establecimiento y la maduración de los bosques riparios en las áreas de anidamiento de esta especie podrían ser importantes para mantener el hábitat disponible para anidar y a la vez mantener o expandir los tamaños actuales de las poblaciones.