Rohwer Vanya G, Pauw Anton, Martin Paul R
Department of Biology , Queen's University , Kingston, Ontario , Canada K7 L 3N6.
Department of Botany and Zoology , Stellenbosch University , Private Bag X1, Matieland 7602 , South Africa.
R Soc Open Sci. 2017 Jan 11;4(1):160538. doi: 10.1098/rsos.160538. eCollection 2017 Jan.
Characterizing many species interactions as mutualisms can be misleading because some members of the interaction derive greater fitness benefits at the expense of other members. We provide detailed natural history data on a suspected bird-plant mutualism in South Africa where many species of birds use fluffy seed material to construct their nests, potentially dispersing seeds for the plant. We focus on a common bird, , which invests heavily in gathering material. Prinias spent 5 of their median 6-day nest construction period adding seed material to their nests and frequently travelled outside their territory boundary to gather material. Yet, prinias gathered primarily fluff and actively avoided gathering seeds. The average prinia nest contained only 6.6 seeds, but contained fluff from 579 seeds. These data suggest that prinias provide limited dispersal benefits to plants. By contrast, the large amounts of fluff in prinia nests, and the effort that prinias invest in gathering it, suggest that prinias benefit from constructing their nests with material. We end by outlining hypotheses for possible fitness benefits that material could provide prinias and other birds.
将许多物种间的相互作用描述为互利共生可能会产生误导，因为相互作用中的一些成员以牺牲其他成员为代价获得了更大的适应性益处。我们提供了关于南非一种疑似鸟类与植物互利共生关系的详细自然史数据，在那里许多鸟类利用蓬松的种子材料来建造它们的巢穴，这可能为植物传播种子。我们关注一种常见的鸟类，即长尾山雀，它在收集材料方面投入巨大。长尾山雀在其平均为期6天的筑巢期里，有5天将种子材料添加到它们的巢穴中，并且经常越过其领地边界去收集材料。然而，长尾山雀主要收集的是绒毛，并积极避免收集种子。平均每个长尾山雀巢中仅含有6.6颗种子，但含有来自579颗种子的绒毛。这些数据表明，长尾山雀为植物提供的传播益处有限。相比之下，长尾山雀巢中大量的绒毛，以及长尾山雀在收集绒毛时投入的精力，表明长尾山雀通过用绒毛材料建造巢穴而受益。我们最后概述了绒毛材料可能为长尾山雀和其他鸟类带来的适应性益处的假设。
