Breeding behaviour and breeding success of feral pigeons in the Bloemfontein urban area
Keywords: Columba livia, tuinduiwe, broeigedrag, broeisukses, neste, eiers, neskuikens, stadsgebied, sentrale Vrystaat
AbstractBreeding activities of feral pigeons (Columba livia) in the Bloemfontein urban area occur�throughout the year with a decrease during the late summer months when seasonal rainfall�in the region reaches a peak. Nest construction is relatively primitive and is characterised by a�loose composition of nesting material on accumulated dry bird droppings. Two eggs represent�the most common clutch size and eggs are usually laid within two days of each other. Both�parents are involved in the incubation process lasting more than two weeks, during which the�eggs undergo a progressive decrease in mass. Recently hatched nestlings are covered in yellow�down and are largely helpless. True feathers only start to emerge after the first week, and from�the third week individuals can move about unsteadily. Apart from the first number of days�after hatching, nestlings of rare single egg clutches constantly maintain a body mass lower�than those from an average clutch. The overall success of 247 breeding pairs for this study was�34%. Egg loss is higher than the mortality rate of nestlings, and is mainly affected by climatic�factors such as rainfall. Predation appears to be the most important factor influencing nestling�mortality. Aggressive interactions between speckled pigeons and rock doves, however, as well�as possible intraspecific aggression also play a significant role.