concepts require individuals to identify relationships between novel stimuli. Previous studies have reported that the ability to learn abstract concepts is found in a wide range of species. In regard to a same/different concept, Clark's nutcrackers (Nucifraga columbiana) and black-billed magpies (Pica hudsonia), two corvid species, were shown to outperform other avian and primate species (Wright et al., 2017). Two additional corvid species, pinyon jays (Gymnorhinus cyanocephalus) and California scrub jays (Aphelocoma californica) chosen as they belong to a different clade than nutcrackers and magpies, were examined using the same set-size expansion procedure of the same/different task (the task used with nutcrackers and magpies) to evaluate whether this trait is common across the Corvidae lineage. During this task, concept learning is assessed with novel images after training. Results from the current study showed that when presented with novel stimuli after training with an 8-image set, discrimination accuracy did not differ significantly from chance for pinyon jays and California scrub jays, unlike the magpies and nutcrackers from previous studies that showed partial transfer at that stage. However, concept learning improved with each set-size expansion, and the jays reached full concept learning with a 128-image set. This performance is similar to the other corvids and monkeys tested, all of which outperform pigeons. Results from the current study show a qualitative similarity in full abstract-concept learning in all species tested with a quantitative difference in the set-size functions, highlighting the shared survival importance of mechanisms supporting abstract-concept learning for corvids and primates. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

中文翻译：

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两种新世界鸦科动物的抽象概念学习，松鸦（Gymnorhinus Cyanocephalus）和加利福尼亚鸦鸦（Aphelocoma Californica）。

概念要求个体识别新刺激之间的关系。先前的研究报告称，在广泛的物种中发现了学习抽象概念的能力。关于相同/不同的概念，克拉克胡桃夹子 (Nucifraga columbiana) 和黑嘴喜鹊 (Pica hudsonia) 这两种鸦科动物的表现优于其他鸟类和灵长类动物 (Wright 等，2017)。使用相同/不同任务的相同集合大小扩展程序检查了另外两个鸦科物种，pinyon jays (Gymnorhinus cyanocephalus) 和加利福尼亚灌木鸦 (Aphelocoma californica)，因为它们属于与胡桃夹子和喜鹊不同的进化枝。任务与胡桃夹子和喜鹊一起使用）来评估这种特征是否在 Corvidae 谱系中很常见。在这个任务中，训练后用新图像评估概念学习。当前研究的结果表明，在用 8 幅图像集训练后呈现新刺激时，识别准确度与松鸦和加州灌木松鸦的概率没有显着差异，这与先前研究中的喜鹊和胡桃夹子不同，后者显示部分转移那个阶段。然而，随着每次集大小的扩展，概念学习得到改进，并且 jays 使用 128 个图像集达到了完整的概念学习。这种表现与其他被测试的鸦科动物和猴子相似，它们的表现都优于鸽子。当前研究的结果表明，在所有被测试的物种中，完全抽象概念学习的定性相似，在集合大小函数上存在定量差异，强调支持鸦科动物和灵长类动物抽象概念学习的机制的共同生存重要性。（PsycInfo 数据库记录 (c) 2021 APA，保留所有权利）。