N Dreiss Amélie, Romano Andrea, Flint Raphaëlle, Bates Sarah, Vermunt Aurélie, Henry Isabelle, A Ruppli Charlène, Roulin Alexandre
Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland.
Department of Environmental Science and Policy, University of Milan, 20133 Milan, Italy.
Animals (Basel). 2020 Oct 1;10(10):1777. doi: 10.3390/ani10101777.
Animals produce vibrations or noises by means of body movements, which can play a role in communication. These behaviors enhance signal transmission or receiver attention and could be specifically used during turn-taking phases of a reciprocal exchange of signals. In the barn owl , nestlings vocalize one after the other to negotiate which individual will have priority access to the impending prey item to be delivered by the parents. Owlets adjust their vocalization to their own hunger level and to their siblings' vocalization, withdrawing from the contest in front of highly vocal, and hence hungry, motivated nestmates. As sibling negotiation is a multicomponent display, we examined whether body movements could also be part of the negotiation process. To this end, we analyzed whether the vocalizations of one nestling affected its nestmate's movements in three separate experiments: in natural nests, in the lab, and using a playback procedure. Nestling barn owls move in a variety of ways, such as repeated tapping of the floor with a foot, scratching the floor with claws, or flapping wings. Body movements were more frequent during the turn-taking phases of vocal interactions, when siblings emitted longer calls and at a greater rate. Once an individual monopolized vocal activity, siblings became less vocal and less active. Moreover, owlets produced more noisy body movements during the phases of vocal interactions which are crucial to prevail in negotiation. Non-vocal physical activities might reinforce vocal signals during sibling to sibling (sib-sib) interactions, or reflect owlets' arousal, in the critical period during which they vocally settle which individual will dominate the competition.
动物通过身体运动产生振动或声音，这些振动或声音在交流中可以发挥作用。这些行为增强了信号传递或接收者的注意力，并且可以在信号相互交换的轮流阶段专门使用。在仓鸮中，雏鸟会依次发出叫声，以协商哪只雏鸟将优先获得即将由父母送来的猎物。雏鸮会根据自己的饥饿程度和兄弟姐妹的叫声来调整自己的叫声，在叫声高亢、因而饥饿且有积极性的同窝雏鸟面前退出竞争。由于兄弟姐妹之间的协商是一种多成分的展示，我们研究了身体运动是否也可能是协商过程的一部分。为此，我们在三个不同的实验中分析了一只雏鸟的叫声是否会影响其同窝雏鸟的运动：在自然巢穴中、在实验室里以及使用回放程序。仓鸮雏鸟有多种运动方式，比如用脚反复轻敲地面、用爪子抓挠地面或拍打翅膀。在叫声互动的轮流阶段，当兄弟姐妹发出更长、频率更高的叫声时，身体运动更为频繁。一旦某个个体垄断了叫声活动，兄弟姐妹的叫声就会减少，活动也会变少。此外，雏鸮在叫声互动的关键阶段会产生更多嘈杂的身体运动，这些阶段对于在协商中获胜至关重要。非发声的身体活动可能会在兄弟姐妹之间的互动中强化发声信号，或者反映雏鸮的兴奋程度，在这个关键时期，它们通过叫声来确定哪个个体将主导竞争。
