Seed dispersal effectiveness by a large-bodied invasive species in defaunated landscapes

Animal-dispersed plants are increasingly reliant on effective seed dispersal provided by small-bodied frugivores in defaunated habitats. In the Neotropical region the non-native wild pig (Sus scrofa) is expanding its distribution and we hypothesized that they can be a surrogate for seed dispersal services lost by defaunation. We performed a thorough analysis of their interaction patterns, interaction frequencies, seed viability and characteristics of the seed shadows they produce. We found 15,087 intact seeds in 56% of the stomachs and 5186 intact seeds in 90% of the scats analyzed, 95% of which were smaller than 10 mm in diameter. Wild pigs were the third most effective disperser among 21 extant frugivore species in a feeding trail experiment in terms of quantity of seeds removed and gut retention time was 70 ±23 h, indicating they can promote long distance seed dispersal. Seed survival after seed handling and gut passage by wild pigs was positively related with seed size, but large se...

在动物区系丧失的栖息地中，依赖动物传播的植物愈发依赖小型食果动物（frugivore）提供的高效种子扩散服务。在新热带区（Neotropical region），外来物种野猪（Sus scrofa）的分布范围持续扩张，我们据此提出假说：野猪可替代因动物区系丧失而缺失的种子扩散生态服务。我们针对其与植物的互作模式、互作频率、种子活力以及其所形成的种子扩散阴影（seed shadow）特征开展了系统性分析。经检测，56%的野猪胃内容物中检出15087粒完整种子，90%的粪样中检出5186粒完整种子，其中95%的种子直径小于10毫米。在一项取食试验中，以移除种子的数量为评价维度，野猪是21种现存食果动物中第三高效的种子扩散者；其肠道滞留时间为70±23小时，表明野猪可助力种子实现长距离扩散。野猪对种子的处理及肠道传递后的种子存活率与种子大小呈正相关，但大型种子……