Data from: Endozoochory of aquatic ferns and angiosperms by mallards in Central Europe

1. Modern literature on plant dispersal by birds focuses mainly on the importance of frugivory and scatter-hoarding, yet recent studies show that endozoochory by migratory waterbirds is an important mechanism of long-distance dispersal for a broad range of plants. Nevertheless, there is a lack of empirical field studies that identify the plants dispersed by waterbirds, and relate them to expectations based on dispersal syndromes. To date, there are no detailed studies of the level of spatial variation in the plant taxa dispersed by a waterbird vector.
2. Five sets of faecal samples (total n = 215) were collected from mallards Anas platyrhynchos on autumn migration in the Tisza and Balaton regions in Hungary, central Europe. Intact diaspores were extracted, identified and their germinability assessed under standard conditions. The plant communities recorded at different sites were compared with PERMANOVA and other multivariate methods.
3. Macrospores of the floating watermoss Salvinia natans were recorded in 32 samples, and a total of 16 macrospores germinated, providing the first field demonstration of endozoochory of ferns by birds. Of 21 angiosperm taxa recorded (of which 8 germinated), 13 were terrestrial species, although the most abundant taxa were aquatic species such as the alkali bulrush Bolboschoenus maritimus and the sago pondweed Potamogeton pectinatus. Two naturalized alien species, the common fig (Ficus carica) and the hackberry (Celtis occidentalis) were also recorded. The plant taxa dispersed varied at two different spatial scales, with minor but significant differences between samples from sites separated by less than 1 km, and major differences between the two regions separated by approximately 220 km.
4. Synthesis. This is a unique study of the spatial variation in plants dispersed by endozoochory by a migratory waterfowl species, with the first demonstration of avian endozoochory of ferns. Most taxa dispersed are generally assumed to disperse by water, wind or self-dispersal, and waterfowl will provide much greater maximum dispersal distances. More such studies are essential before we can understand which plants are dispersed by migratory birds, because morphological dispersal syndromes do not allow us to make adequate a priori predictions.

1. 当前关于鸟类传播植物的研究文献主要聚焦于食果性（frugivory）与分散贮藏（scatter-hoarding）的重要性，但近期研究表明，迁徙水鸟（migratory waterbirds）的体内传播（endozoochory）是广泛植物类群实现长距离传播的关键机制。然而，目前仍缺乏通过野外实证研究明确水鸟传播的植物类群，并将其与基于传播综合征（dispersal syndromes）的预期相匹配的相关工作。迄今为止，尚未有研究详细探讨水鸟媒介传播的植物类群的空间变异程度。
2. 研究团队于中欧匈牙利的蒂萨河与巴拉顿湖地区，采集了秋季迁徙期间的绿头鸭（Anas platyrhynchos）粪便样本共5组，总计215份。研究人员提取并鉴定了样本中的完整繁殖体（intact diaspores），并在标准条件下评估其萌发能力（germinability）。通过置换多元方差分析（PERMANOVA）及其他多元统计方法，对不同采样点记录的植物群落进行了比较分析。
3. 研究在32份样本中检测到了槐叶萍（Salvinia natans）的大孢子（macrospores），其中共计16枚大孢子成功萌发，这首次通过野外实证证实了鸟类对蕨类植物的体内传播。本次共记录到21个被子植物类群，其中8个类群的繁殖体可萌发；13个类群为陆生物种，但优势类群为水生物种，如碱地藨草（Bolboschoenus maritimus）与篦齿眼子菜（Potamogeton pectinatus）。此外还记录到2种归化外来物种：无花果（Ficus carica）与西美朴树（Celtis occidentalis）。本次研究发现，水鸟传播的植物类群存在两种尺度的空间变异：间距不足1公里的采样点之间的样本仅存在细微但显著的差异，而两个相距约220公里的区域之间则存在显著的群落差异。
4. 研究总结：本研究首次针对迁徙水禽的体内传播介导的植物传播空间变异展开研究，同时首次证实了鸟类对蕨类植物的体内传播。多数被传播的植物类群通常被认为依靠水体、风力或自主传播实现扩散，而水禽能够实现更远的最大传播距离。由于仅依靠形态学传播综合征无法做出充分的先验预测，因此亟需开展更多同类研究，以明确哪些植物可通过迁徙鸟类实现传播。