How flightless animals disperse to remote oceanic islands is a key unresolved question in biogeography. The flightless Pachyrhynchus weevils represent repetitive colonization history in West Pacific islands, which attracted our interests about how some weevils have successfully dispersed in the reverse direction against the sea current. Here, we propose endozoochory as a possible mechanism that the eggs of the weevils might be carried by embedded in the fruits as the food of frugivorous birds. In this study, Pachyrhynchus eggs were embedded in small pieces of persimmon fruits (Diospyros kaki) and fed to captive frugivorous birds. After digestion, 83%–100% eggs were retrieved from the feces of a bulbul (Hypsipetes leucocephalus) and two thrushes (Turdus chrysolaus). The retrieved eggs had hatching rates higher than 84%, which were not different from the control. In contrast, no egg was retrieved from the feces of the frugivorous pigeon (Treron sieboldii), which took a longer retention time in the guts. Our study identified that the eggs of Pachyrhynchus weevils are possible to be transported by internal digesting in some bird species.

中文翻译：

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鸡蛋通过鸟类肠道存活——一种不会飞的象鼻虫跨洋传播的可能机制

不会飞的动物如何分散到偏远的海洋岛屿是生物地理学中一个尚未解决的关键问题。不会飞的Pachyrhynchus象鼻虫代表了西太平洋岛屿重复的殖民历史，这引起了我们的兴趣，即一些象鼻虫是如何逆着海流成功地逆向分散的。在这里，我们提出了一种可能的机制，即象鼻虫的卵可能被嵌入水果中，作为食果鸟类的食物。在这项研究中，将Pachyrhynchus卵嵌入小片柿子果实 ( Diospyros kaki ) 中，喂给圈养的食果鸟类。消化后，83%–100% 的卵从球茎 ( Hypsipetes leucocephalus)的粪便中取出）和两只画眉（Turdus chrysolaus）。回收的卵孵化率高于84%，与对照无差异。相比之下，没有从食果鸽 ( Treron sieboldii )的粪便中取出卵，后者在肠道中的保留时间更长。我们的研究发现，在某些鸟类中，Pachyrhynchus象鼻虫的卵可能通过内部消化进行运输。