Fruit ingestion by frugivores and the subsequent passage of seeds through their digestive tract can influence seed germination patterns. The removal of germination inhibitors contained in the fruit pulp (deinhibition effect), and/or the abrasion of the seed coat (scarification effect), can modify the probability and speed of seed germination. We followed seven groups of black-and-gold howler monkeys (Alouatta caraya) in northeastern Argentina between November 2012 and January 2013 to study the effect of seed passage through the howler monkeys’ gut on seed germination. For three native and one exotic species, we compared the proportion of germination and germination times among seeds in three different treatments: gut-passed seeds (GP), manually extracted seeds from fruits (ME), and seeds in intact fruits (IF). Paired comparisons between treatments allowed us to assess the overall effect of seed passage (total effect without distinguishing individual effects, GP vs. IF), deinhibition effect (ME vs. IF), and scarification effect (GP vs. ME). Our results suggest that passage through the howler monkeys’ gut enhances seed germination by an increase in the proportion of germinated seeds and/or by a reduction in germination times. We found that deinhibition enhanced germination in three out of the four studied species, while scarification enhanced germination in one and decreased germination in another species. Our work highlights that gut passage may affect seed germination by different mechanisms, and all of these mechanisms should be considered in germination studies. It also emphasizes the importance of A. caraya as a seed disperser in northeastern Argentina, showing the high quality of the treatment provided to seeds.

中文翻译：

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野生黑金吼猴（Alouatta caraya）散播的本地和外来种子的萌发：评估去抑制和松土效果

食果动物摄入果实以及随后种子通过消化道会影响种子发芽模式。去除果肉中含有的发芽抑制剂（去抑制作用）和/或种皮的磨损（松土作用），可以改变种子发芽的概率和速度。2012 年 11 月至 2013 年 1 月期间，我们在阿根廷东北部跟踪了七组黑金吼猴 (Alouatta caraya)，以研究种子通过吼猴肠道对种子萌发的影响。对于三种本地物种和一种外来物种，我们比较了三种不同处理中种子的发芽比例和发芽时间：通过肠道的种子 (GP)、从果实中手动提取种子 (ME) 和完整果实中的种子 (IF)。处理之间的配对比较使我们能够评估种子传代的整体效果（不区分个体效果的总效果，GP 与 IF）、去抑制效果（ME 与 IF）和松土效果（GP 与 ME）。我们的结果表明，通过吼猴的肠道通过增加发芽种子的比例和/或减少发芽时间来促进种子发芽。我们发现去抑制促进了四个研究物种中的三个物种的发芽，而松土增强了一个物种的发芽并减少了另一个物种的发芽。我们的工作强调肠道通道可能通过不同的机制影响种子萌发，所有这些机制都应在萌发研究中考虑。它还强调了A的重要性。