R script from Goats show higher behavioural flexibility than sheep in a spatial detour task

The ability to adapt to changing environments is crucial for survival and has evolved based on socio-ecological factors. Goats and sheep are closely related, with similar social structures, body sizes and domestication levels, but different feeding ecologies, i.e. goats are browsers and sheep are grazers. We investigated whether goats' reliance on more patchily distributed food sources predicts an increased behavioural flexibility compared to sheep. We tested 21 goats and 28 sheep in a spatial A-not-B detour task. Subjects had to navigate around a straight barrier through a gap at its edge. After one, two, three or four of these initial A trials, the gap was moved to the opposite end and subjects performed four B trials. Behaviourally more flexible individuals should move through the new gap faster, while those less behaviourally flexible should show greater perseveration. While both species showed an accuracy reduction following the change of gap position, goats recovered from this perseveration error from the second B trial onwards, whereas sheep did so only in the fourth B trial, indicating differences in behavioural flexibility between the species. This higher degree of flexibility in goats could be linked to differences in their foraging strategies.

适应多变环境的能力对物种生存至关重要，其演化进程由社会生态因素共同塑造。山羊与绵羊亲缘关系紧密，二者具有相似的社会结构、体型大小与驯化水平，但采食生态存在显著差异：山羊为灌木啃食者（browser），绵羊为草本啃食者（grazer）。本研究旨在验证：相较于绵羊，山羊对分布更为零散的食物资源的依赖，是否意味着其具备更高的行为灵活性。我们针对21只山羊与28只绵羊开展了空间A非B迂回任务（spatial A-not-B detour task）测试：受试动物需绕越一道直形障碍，从其边缘的预设缝隙通过。在完成1、2、3或4次初始A试次后，缝隙将被移至障碍的另一端，受试动物随后需完成4次B试次。行为灵活性更强的个体，应能更快速地通过新缝隙；而行为灵活性较弱的个体，则更易出现显著的行为固着。尽管两种动物在缝隙位置改变后均出现了任务正确率下降，但山羊从第二次B试次起便从固着错误中恢复，而绵羊仅在第四次B试次时才完成恢复，这表明二者的行为灵活性存在物种差异。山羊更高的行为灵活性，或与其独特的采食策略密切相关。