A neotropical canid as seed disperser in semiarid areas of Brazil

Abstract Seed dispersal consists of diaspore removal from parental plants and relocation to new locations where seeds can germinate and grow seedlings. Seeds that passage through an animal's digestive tract may have changes in percentages, speed, and synchronization of germination. Cerdocyon thous is an omnivorous canid from South America and we investigated its role as a dispersing agent, in semiarid areas, by analyzing feces in three areas of northeastern Brazil. Seeds found in feces and removed directly from fruit (control) had their viabilities evaluated in germination tests, where germinability, germination time of 50% of viable seeds (t50), the emergence velocity, and synchronization indices were determined. Of the evaluated species, the cactus Pilosocereus gounellei showed differences in the parameters between treatments. The passage of seeds of P. gounellei through the canid digestive tract decreased germinability and the germination speed and increased the t50. For the other species, there were no difference between treatments. Therefore, C. thous influenced the germination success and pattern of this cactus, although it did not influence the reproductive behavior of most species. This canid was considered an effective seed disperser in semiarid areas because it moved seeds from the parental plant to sites suitable for its germination.