Crudele Ignacio, Hauber Mark E, Reboreda Juan C, Fiorini Vanina D
Departamento de Ecología, Genética y Evolución and IEGEBA-UBA-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón II Ciudad Universitaria, Buenos Aires C1428EGA, Argentina.
Department of Evolution, Ecology, and Behavior, School of Integrative Biology, University of Illinois, Urbana-Champaign, IL 61801, USA.
R Soc Open Sci. 2023 May 10;10(5):221477. doi: 10.1098/rsos.221477. eCollection 2023 May.
Eggs are critically important for avian reproduction as all birds are oviparous. Accordingly, the recognition and care of own eggs represent the cornerstones of avian breeding, whereas the elimination of foreign objects, including brood-parasitic eggs and non-egg items from the nest are known to also increase fitness by refocusing incubation effort on the parents' own eggs. But egg recognition also plays a role in some avian obligate brood parasites' reproductive strategy through the pecking of already present eggs in the hosts' clutch to reduce nestmate competition with the parasite's own hatchling. Here we tested egg shape recognition in this parasitic egg-pecking context by exposing two different series of 3D printed models to captive obligate brood-parasitic shiny cowbirds () in artificial nests. Natural egg-shaped models were pecked more often compared with increasingly thinner models, but there was no effect of increasing angularity on pecking rates, implying that a natural, rather than an artificial, range of variability elicited adaptive responses from parasitic cowbirds.
由于所有鸟类都是卵生的，所以蛋对鸟类繁殖至关重要。因此，识别和照料自己的蛋是鸟类繁殖的基石，而从巢中清除异物，包括巢寄生的蛋和非蛋物品，已知也会通过将孵化精力重新集中在亲鸟自己的蛋上而提高适应性。但是蛋的识别在一些鸟类专性巢寄生者的繁殖策略中也起作用，即通过啄宿主窝中已有的蛋来减少与寄生者自己幼雏的巢内竞争。在这里，我们通过在人工巢中向圈养的专性巢寄生的辉拟八哥（）展示两系列不同的3D打印模型，测试了在这种寄生性啄蛋情境下对蛋形状的识别。与越来越薄的模型相比，自然蛋形模型被啄的频率更高，但棱角增加对啄蛋率没有影响，这意味着自然而非人为的变异性范围引发了寄生性辉拟八哥的适应性反应。
