Nawroth Christian, von Borell Eberhard
Department of Animal Husbandry and Ecology, Institute of Agricultural and Nutritional Sciences, Martin-Luther-University, Theodor-Lieser-Str. 11, 06120, Halle, Germany,
Anim Cogn. 2015 May;18(3):757-66. doi: 10.1007/s10071-015-0842-8. Epub 2015 Feb 4.
Recently, foraging strategies have been linked to the ability to use indirect visual information. More selective feeders should express a higher aversion against losses compared to non-selective feeders and should therefore be more prone to avoid empty food locations. To extend these findings, in this study, we present a series of studies investigating the use of direct and indirect visual and auditory information by an omnivorous but selective feeder-the domestic pig. Subjects had to choose between two buckets, with only one containing a reward. Before making a choice, the subjects in Experiment 1 (N = 8) received full information regarding both the baited and non-baited location, either in a visual or auditory domain. In this experiment, the subjects were able to use visual but not auditory cues to infer the location of the reward spontaneously. Additionally, four individuals learned to use auditory cues after a period of training. In Experiment 2 (N = 8), the pigs were given different amounts of visual information about the content of the buckets-lifting either both of the buckets (full information), the baited bucket (direct information), the empty bucket (indirect information) or no bucket at all (no information). The subjects as a group were able to use direct and indirect visual cues. However, over the course of the experiment, the performance dropped to chance level when indirect information was provided. A final experiment (N = 3) provided preliminary results for pigs' use of indirect auditory information to infer the location of a reward. We conclude that pigs at a very young age are able to make decisions based on indirect information in the visual domain, whereas their performance in the use of indirect auditory information warrants further investigation.
最近，觅食策略已与使用间接视觉信息的能力联系起来。与非选择性觅食者相比，更具选择性的觅食者应该对损失表现出更高的厌恶感，因此应该更倾向于避开没有食物的位置。为了扩展这些发现，在本研究中，我们进行了一系列研究，调查杂食性但有选择性的觅食者——家猪对直接和间接视觉及听觉信息的使用情况。实验对象必须在两个桶之间做出选择，其中只有一个桶里有奖励。在实验1（N = 8）中，实验对象在做出选择之前，会在视觉或听觉领域获得关于有饵桶和无饵桶位置的全部信息。在这个实验中，实验对象能够自发地使用视觉线索而非听觉线索来推断奖励的位置。此外，有四只个体在经过一段时间的训练后学会了使用听觉线索。在实验2（N = 8）中，给猪提供了关于桶内物品的不同数量的视觉信息——同时提起两个桶（完整信息）、有饵桶（直接信息）、空桶（间接信息）或根本不提起桶（无信息）。作为一个群体，实验对象能够使用直接和间接视觉线索。然而，在实验过程中，当提供间接信息时，表现下降到了随机水平。最后一个实验（N = 3）提供了猪使用间接听觉信息推断奖励位置的初步结果。我们得出结论，幼猪能够基于视觉领域的间接信息做出决策，而它们在使用间接听觉信息方面的表现还有待进一步研究。
