Influencia de la edad del nidal y de la presencia de otras especies sobre las fechas de puesta de la Carraca (Coracias garrulus, L.) en estepas de Extremadura (SO península ibérica)

Abstract

lnfluence of nest-box age and occurrence of other species on laying time of the Roller (Coracias garrulus, L.) in steppes of the Extremadura region (SW lberian peninsula)
Laying time in Roller (Coracias garrulus) was studied in two areas of the lberian peninsula during 1988-1991 period. The mean laying date was 31 May + 8.9 days (n = 641). Egg-laying of Rollers was earlier than in northern Palearctic populations, probably due to an earlier spring in the more southern latitude. There were significant differences in laying time in relation to years. With respect to nest-box age, no significant differences were detected in laying time. However, Jackdaw and Roller occurrences were determinant on laying time in the studied population.