INFLUENCE OF FOOD ABUNDANCE AND QUALITY ON RABBIT FLUCTUATIONS - CONSERVATION AND MANAGEMENT IMPLICATIONS IN DONANA-NATIONAL-PARK (SW SPAIN)

European rabbits (Oryctolagus cuniculus) are the major prey in Spain f or several endangered carnivores and raptors. In recent years, many di fferent efforts have been directed at increasing rabbit populations, a nd thus enhancing the survival of these endangered predators. The aim of this work was to improve our understanding of the factors that infl uence the natural variation in rabbit populations, specially those reg arding on the food abundance and quality, and to discuss the efforts a ctually used to manage rabbit populations. Estimates of rabbit abundan ce were obtained monthly from roadside counts during a 25 month period developed at Donana National Park. Simultaneously samples of the herb aceous layer were obtained from the area covered by censuses. Fluctuat ions in rabbit abundance were compared with chances in biomass and qua lity of the herbaceous plants. Rabbit abundance showed the best fit wi th the total protein availability in the herbaceous layer Variations i n the precipitation pattern between years, which affected both food av ailability and rabbit reproduction, and the incidence of the first epi zootic of the rabbit hemorrhagic disease, caused the observed differen ces between maximum values of rabbit abundance in two consecutive year s. The relative importance of other factors influencing rabbit numbers in Dor?ana including myxomatosis, predation, and competition for food with large herbivores is discussed.