DataSheet1.XLSX

For tens of thousands of years, passenger pigeons (Ectopistes migratorius) were a dominant member of eastern North American forest communities, with megaflocks comprising up to several billion individuals. The extinction of passenger pigeons in the early twentieth century undoubtedly influenced associated species and ecosystems as interactions stemming from the pigeons disappeared suddenly. Here, we strive to better understand what was probably one of the most significant of these interactions—that between passenger pigeons and seed bearing trees. Using the band-tailed pigeon (Patagioenas fasciata) and the rock dove (Columba livia) as physical and ecological proxies, we evaluated passenger pigeon dietary range and potential to disperse seeds. Our findings suggest that the passenger pigeon's dietary range, observed historically to be taxonomically broad, was constrained to certain seed sizes due to bill gape size. In addition, we conclude that the digestive process invariably destroyed consumed seeds but the potential for a nutrition/dispersal mutualism might still have existed via regurgitation and post-mortem release of crop contents. Our results highlight the range of ecological interactions that can be lost with species' extinction and the inherent challenge of understanding the consequences of those interactions.

数万年来，候鸟鸽（Ectopistes migratorius）一直是北美东部森林生态系统的优势种群，其超大型群组可达数十亿个体。然而，在二十世纪初，候鸟鸽的灭绝无疑对与之相关的物种和生态系统产生了深远影响，因为与鸽子的互动突然消失。本研究旨在深入探讨这些可能的影响之一——即候鸟鸽与种子植物之间的相互作用。通过以斑尾鸽（Patagioenas fasciata）和斑鸠（Columba livia）作为物理和生态替代物，我们评估了候鸟鸽的饮食范围及其散布种子的潜力。研究发现，历史上观察到的候鸟鸽饮食范围在分类学上较为广泛，但由于喙部张开的限制，其饮食范围被特定种子大小所约束。此外，我们得出结论，消化过程不可避免地破坏了所消费的种子，但通过反刍和尸体释放嗉囊内容物的营养/散布互利共生潜力可能仍然存在。我们的研究结果突显了物种灭绝可能导致生态互动范围的丧失，以及理解这些互动后果所固有的挑战。