Abstract To maintain group cohesion while coordinating group movements, individuals might use signals to advertise the location of a route, their intention to initiate movements, or their position at a given time. In highly mobile animals, the latter is often accomplished through contact calls that are emitted at different rates by group members. Here, we describe and quantify intra- and intergroup variation in contact calling rates in Spix’s disc-winged bats ( Thyroptera tricolor ), a species that employs distinct inquiry and response calls to coordinate group movements during flight and while announcing roost locations. We evaluate the extent to which groups are composed of individuals with similar calling rates and estimate variation among and within groups. Our results show large variation in response calling rates among and within groups, both in terms of calling rates and the probability of being vocal or not; for example, a large portion (35%) of bats sampled did not produce these signals. For inquiry calls, we found that variation in calling rates was greater within than among groups, and in contrast to response calls, only a few individuals (3%) did not produce inquiry calls. Overall, we found support for the existence of intra- and intergroup differences in the context of contact calling in disc-winged bats, and our results suggest that different mechanisms may promote the evolution and maintenance of varying calling rates for the two types of calls studied. Significance statement Animal communication networks are comprised of individuals with different vocal behaviors. However, we still do not fully understand the mechanisms that facilitate individual and group variation in vocal behavior and how these differences affect group cohesion in highly mobile organisms. Here, we describe and quantify contact calling behavior in Spix’s disc-winged bats ( Thyroptera tricolor ) and evaluate whether vocal behavior is associated with group membership and call type. We found consistent individual differences in contact calling rates, as well as among-group variation in calls associated to roost finding. Our study provides a baseline for generating hypotheses regarding the costs and benefits of contact call production during group movements.

中文翻译：

---

上下文中的联系呼叫：发声率的组内和组间变化取决于呼叫的功能

摘要 为了在协调群体运动的同时保持群体凝聚力，个人可能会使用信号来通告路线的位置、他们发起运动的意图或他们在给定时间的位置。在高度移动的动物中，后者通常是通过群体成员以不同速率发出的接触呼叫来实现的。在这里，我们描述并量化了 Spix 盘翅蝙蝠 ( Thyroptera tricolor ) 的群内和群间接触呼叫率的变化，该物种采用不同的询问和响应呼叫来协调飞行期间和宣布栖息地位置的群体运动。我们评估组由具有相似呼叫率的个人组成的程度，并估计组间和组内的变化。我们的结果显示组内和组内的响应调用率差异很大，在通话率和是否发声的可能性方面；例如，采样的大部分蝙蝠 (35%) 不会产生这些信号。对于询问电话，我们发现组内通话率的变化大于组间通话率，与响应电话相比，只有少数人 (3%) 没有发出询问电话。总体而言，我们发现在盘翅蝙蝠接触呼叫的背景下存在组内和组间差异的支持，我们的结果表明，不同的机制可能会促进所研究的两种呼叫类型的不同呼叫率的演变和维持. 意义声明 动物交流网络由具有不同声音行为的个体组成。然而，我们仍然不完全了解促进个体和群体发声行为变异的机制，以及这些差异如何影响高度流动的生物体的群体凝聚力。在这里，我们描述和量化了 Spix 盘翅蝙蝠（三色甲状腺翅目）中的接触呼叫行为，并评估了发声行为是否与组成员身份和呼叫类型相关。我们发现联系呼叫率的个体差异一致，以及与栖息地发现相关的呼叫的组间差异。我们的研究提供了一个基线，用于生成关于群体移动期间联系电话产生的成本和收益的假设。我们描述并量化了 Spix 盘翅蝙蝠（三色甲状腺翅目）的接触呼叫行为，并评估了声音行为是否与群体成员和呼叫类型相关。我们发现联系呼叫率的个体差异一致，以及与栖息地发现相关的呼叫的组间差异。我们的研究提供了一个基线，用于生成关于群体移动期间联系电话产生的成本和收益的假设。我们描述并量化了 Spix 盘翅蝙蝠（三色甲状腺翅目）的接触呼叫行为，并评估了声音行为是否与群体成员和呼叫类型相关。我们发现联系呼叫率的个体差异一致，以及与栖息地发现相关的呼叫的组间差异。我们的研究提供了一个基线，用于生成关于群体移动期间联系电话产生的成本和收益的假设。