again in a nearby alternative nest; or they might wait until the geese have left the nest with their goslings, or they abandon breeding for that year. Urban habitats Following a south and westwards range expansion of black sparrowhawks in South Africa, they also colonised the urban and suburban areas of Cape Town where they have thrived in the 21st century, with none of the expected negative impacts on their health that might have been expected from the disturbances associated with a novel climate (from a subtropical, summer rainfall regimen to a Mediterranean, winter rainfall region), or other possible sources of stress in their newly urbanised environments. This is probably due to the abundance of prey, mainly various species of Columbidae (the wide variety of pigeons and doves) in these urban areas, and, therefore, their lack of nutritional stress. The level of urbanisation does not have a negative impact on their breeding success, either. Black sparrowhawks in more urbanised habitats are however more successful early in the season, while black sparrowhawks in less urbanised habitats perform better later in the breeding season. Behaviour Vocalizations They are mostly silent except during the breeding season. Males make short, sharp "keeyp" contact calls when arriving with prey, to which the females respond with lower pitched "kek" sounds. Before the male arrives with food, however, the female will solicit food with loud, high pitched drawn out "kweeeeee-uw" sounds. Both sexes produce alarm calls, and characteristic mating cries. The chicks, but especially the juveniles, are very noisy, making high pitched "weeeeeeeeh" sounds, especially when soliciting food. Diet Black sparrowhawks prey primarily on mid-sized birds. Most prey is spotted from a foliage-concealed perch, which is then killed in flight during a short flying dash. Less often, they stoop or chase prey seen during low or high flight over open country or near the canopy of trees and, in some cases, may even pursue prey on foot. Although kills are often made in under a minute after the initial attack, occasionally this species may engage in a prolonged pursuit lasting several minutes. They have been known to scan for ant swarms in order to predate birds that are attracted to these. Most birds preyed on by this species are in the size range of . Doves are the primary prey of males, whereas females take a greater quantity of larger prey such as pigeons and francolins. They