PDF(Pubmed)
Abstract：
In their natural environment, animals face a variety of ecological and social challenges, which might be linked to the emergence of different cognitive skills. To assess inter-specific variation in cognitive skills, we used ungulates as a study model, testing a total of 26 captive individuals across 5 different species (i.e., dwarf goats, Capra aegagrus hircus, llamas, Lama glama, guanacos, Lama guanicoe, zebras, Equus grevyi, and rhinos, Diceros bicornis michaeli). Across species, we used the same well-established experimental procedures to test individuals\' performance in naïve physics tasks, i.e. object permanence, short-term spatial memory, causality, understanding of object properties, and gravity. Our results revealed that study subjects showed object permanence, were able to remember the position of hidden food after up to 60 s, and inferred the position of hidden food from the sound produced or not produced when shaking containers. Moreover, they showed an understanding of basic object properties, being able to locate objects hidden behind occluders based on their size and inclination, and could reliably follow the trajectory of falling objects across different conditions. Finally, inter-specific differences were limited to the understanding of object properties, and suggest that domesticated species as goats might perform better than non-domesticated ones in tasks requiring these skills. These results provide new information on the cognitive skills of a still understudied taxon and confirm ungulates as a promising taxon for the comparative study of cognitive evolution.
摘要：
在他们的自然环境中，动物面临各种生态和社会挑战，这可能与不同认知技能的出现有关。为了评估认知技能的特定差异，我们用有蹄类动物作为研究模型,测试了5个不同物种的26个圈养个体(即，矮山羊,Capraaegagrushircus，美洲驼,格拉玛,guanacos,关尼科喇嘛,斑马,Equusgrevyi,还有犀牛,Dicerosbicornismichaeli)。跨物种，我们使用同样完善的实验程序来测试个人在幼稚物理任务中的表现，即对象持久性，短期空间记忆,因果关系，理解对象属性，和重力。我们的结果表明，研究对象表现出客体持久性，能够在60年代后记住隐藏食物的位置，并从摇动容器时产生或不产生的声音推断隐藏食物的位置。此外，他们展示了对基本对象属性的理解，能够根据遮挡物的大小和倾斜度定位隐藏在遮挡物后面的对象，并且可以可靠地跟踪不同条件下坠落物体的轨迹。最后,特定间的差异仅限于对对象属性的理解，并建议驯化物种作为山羊在需要这些技能的任务中可能比非驯化物种表现更好。这些结果为仍未研究的分类单元的认知技能提供了新信息，并确认有蹄类动物是认知进化比较研究的有前途的分类单元。
