Fruit removal service by birds: the crop-size role in a seasonal ecosystem

Abstract

Abstract: Mutualistic interactions, like frugivory, are a key element in maintaining ecosystems. The abundance of resources has been proposed as an important factor in determining the intensity and frequency of this type of interaction. We used Bursera graveolens as a model in order to determine to what extent fruit availability, conditions frugivory in a seasonally dry tropical forest. We jointly analyzed the effect to the neighborhood and individuals scale and from plant and bird perspective. We evaluated the interaction in 16 B. graveolens focal trees. Around each tree we determined bird species abundance and the number of fruit in both the focal tree and the neighborhood including its focal tree. Our results show that the crop size determines the intensity of neighborhood visitation and the fruit removal at individual scale. We found that plant-plant facilitation was prevalent at the neighborhood scale and competition was the most predominant plant-plant interaction at the individual scale. These results suggested that fruit-rich neighborhoods are more attractive to fruit-eaters, however, within these neighborhoods, plant individuals compete for dispersal services.