Department of Zoology, University of Cambridge, Cambridge, United Kingdom.
DST-NRF Centre of Excellence at the FitzPatrick Institute of African Ornithology, University of Cape Town, Rondebosch, Cape Town, South Africa.
Evolution. 2020 Nov;74(11):2526-2538. doi: 10.1111/evo.14057. Epub 2020 Jul 28.
Brood parasites use the parental care of others to raise their young and sometimes employ mimicry to dupe their hosts. The brood-parasitic finches of the genus Vidua are a textbook example of the role of imprinting in sympatric speciation. Sympatric speciation is thought to occur in Vidua because their mating traits and host preferences are strongly influenced by their early host environment. However, this alone may not be sufficient to isolate parasite lineages, and divergent ecological adaptations may also be required to prevent hybridization collapsing incipient species. Using pattern recognition software and classification models, we provide quantitative evidence that Vidua exhibit specialist mimicry of their grassfinch hosts, matching the patterns, colors and sounds of their respective host's nestlings. We also provide qualitative evidence of mimicry in postural components of Vidua begging. Quantitative comparisons reveal small discrepancies between parasite and host phenotypes, with parasites sometimes exaggerating their host's traits. Our results support the hypothesis that behavioral imprinting on hosts has not only enabled the origin of new Vidua species, but also set the stage for the evolution of host-specific, ecological adaptations.
巢寄生者利用其他亲代的照顾来养育自己的幼鸟，有时还会采用拟态来欺骗宿主。雏寄生雀属的雀类就是印记在同域物种形成中作用的典型例子。同域物种形成被认为发生在雏寄生雀属中，因为它们的交配特征和宿主偏好受到其早期宿主环境的强烈影响。然而，仅仅这一点可能不足以隔离寄生虫谱系，也可能需要不同的生态适应来防止杂交破坏初期物种。我们使用模式识别软件和分类模型，提供了定量证据表明雏寄生雀属专门模仿它们的草雀宿主，匹配各自宿主雏鸟的图案、颜色和声音。我们还提供了雏寄生雀属乞食时姿势成分的模仿的定性证据。定量比较揭示了寄生虫和宿主表型之间的微小差异，寄生虫有时会夸大其宿主的特征。我们的研究结果支持这样一种假设，即宿主的行为印记不仅使新的雏寄生雀属物种得以起源，也为宿主特异性的生态适应进化奠定了基础。
