Uso do habitat por urubus (Família Cathartidae Lafresnaye, 1839) em áreas urbanas e naturais em Manaus, Amazonas

Abstract

Urban expansion has favored the establishment and population growth of some vulture species (Family Cathartidae) in highly anthropic environments. The positive relationship between vultures and anthropogenic landscapes has generated conflicts with humans, including livestock predation, nest- and roost-associated nuisance, and a significant increase of the risk of collision with aircrafts. In this study we showed: (1) how some urban structures influence the occurrence of Black Vultures (Coragyps atratus) and Turkey Vultures (Cathartes aura); (2) ecological factors influencing communal roost site selection by Black Vultures; and (3) the use of artificial thermal sources by vultures in Manaus, Amazonas, Brazil. The results clearly demonstrated two different patterns of habitat use by the two species. Black Vultures were associated with urban structures which provided large amounts of food, such as open garbage containers and polluted streams. Turkey Vultures were strongly associated with forest remnants and avoided sites with large numbers of Black Vultures (e.g., street markets). Communal roost site selection by Black Vultures also was directly influenced by proximity to areas with higher food availability. Another interesting finding, related to behavioral ecology, was that the vultures are using air thermals from vent pipes of thermal power plants as an aid for soaring, assisting the movements between roosts and foraging sites, as well as extend their daily activities. Based on our results it is possible to suggest management measures aimed at reducing the problems caused by vultures. For Black Vultures, management should focus on urban structures which provide large amounts of food (e.g., the replacement of open with closed garbage containers and the ecological recovery of polluted streams). For Turkey Vultures, interventions could concentrate on areas where these birds are causing problems (e.g., airport environments), and should include the elimination of animal carcasses. Further management measures, such as blocking access to roosts and perches, nest removal, or harassment could also be used for both vulture species.