Abstract

A mark test allows us to assess if an animal can recognize its reflection in a mirror. The capability of self-recognition provides evidence of self-awareness, and it has been revealed only in a few animals with highly developed brains such as great apes, dolphins, elephants, magpies, and Clark’s nutcrackers. We investigated this capability in the hooded crow, another representative of corvids. Our experiment consisted of three stages: exposure to a mirror to examine its reflecting characteristics; a test (in front of the mirror, birds had a mark on the frontlets); and control (without mirror, birds had a mark on the frontlets). During the first sessions in front of the mirror, the crows, like other animals, revealed social behavior, pushing the mirror with the head and/or chest and pecking and scratching it with claws. These reactions almost ended in 2–3 sessions. None of the crows groomed the mark zone during the test (in front of the mirror, birds had a mark) more than in the control (without a mirror, birds had a mark). Therefore, none of the crows showed self-recognition. Four of six crows groomed the mark zone without a mirror for a longer time than in front of the mirror. This may be because crows felt the mark stuck to their feathers and they were more quiet and attentive to their senses without a mirror. Our findings suggest that the marking technique could be improved and crows need more time to examine mirror characteristics before the next test.

中文翻译：

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评估带帽乌鸦（乌鸦座cornix）中的镜子自我识别能力

摘要

标记测试使我们能够评估动物是否可以识别镜子中的反射。自我识别的能力提供了自我意识的证据，只有少数高度发达的大脑动物（例如大猿，海豚，大象，喜pies和克拉克的胡桃夹子）才显示出这种能力。我们在带帽乌鸦（又名科迪奇犬）中研究了这种能力。我们的实验包括三个阶段：暴露于镜子以检查其反射特性；测试（在镜子前，鸟类在前额上有标记）；和控制（没有镜子，鸟类在前额上有标记）。在镜子前的第一个阶段中，乌鸦像其他动物一样，表现出社交行为，用头部和/或胸部推动镜子，啄食并用爪子抓挠镜子。这些反应几乎在2-3节中结束。在测试过程中，没有任何乌鸦修饰标记区域（在镜子前，鸟类有标记）比对照（在没有镜子的情况下，鸟类有标记）修饰了标记区域。因此，没有一只乌鸦表现出自我识别。六只乌鸦中的四只在没有镜子的情况下修饰标记区域的时间比在镜子前更长。这可能是因为乌鸦感觉到羽毛上粘着的痕迹，并且他们没有镜子就更加安静和专心。我们的发现表明，标记技术可能会得到改善，乌鸦在下一次测试之前需要更多时间来检查镜面特征。没有一只乌鸦表现出自我认可。六只乌鸦中的四只在没有镜子的情况下修饰标记区域的时间比在镜子前更长。这可能是因为乌鸦感觉到羽毛上粘着的痕迹，并且他们没有镜子就更加安静和专心。我们的发现表明，标记技术可能会得到改善，乌鸦在下一次测试之前需要更多时间来检查镜面特征。没有一只乌鸦表现出自我认可。六只乌鸦中的四只在没有镜子的情况下修饰标记区域的时间比在镜子前更长。这可能是因为乌鸦感觉到羽毛上粘着的痕迹，并且他们没有镜子就更加安静和专心。我们的发现表明，标记技术可能会得到改善，乌鸦在下一次测试之前需要更多时间来检查镜面特征。