Fertilidad de la Avutarda (Otis tarda L.) en Villafáfila (Zamora) en 1984

Resumen

Fertility of the Great Bustard (Otis tarda L.) in Villafafila (Zamora, Spain) in 1984
The fertility of a resident population of 450 Great Bustards in Villafáfila (Zamora) is studied. Two simultaneous methods of work are used: localization of nests and visualization of hens with chicks. The predation percentage on nests is of 50%. Clutch-size is 2.46 eggs / nest. The mortality of chicks up to two months old is 42.15% and the total fertility (chicks / hen) is of 0.67. The majority of losses during the breeding season is due to agricultura1 machinery, and measures to avoid losses are necessary.