Dynamics of direct inter-pack encounters in endangered African wild dogs
Dynamics of direct inter-pack encounters in endangered African wild dogs
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DOI：
10.1007/s00265-017-2338-9
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发表时间：
2017-08-01
影响因子：
2.3
通讯作者：
McNutt, J. Weldon
中科院分区：
文献类型：
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作者：
Jordan, Neil R.;Buse, Christopher;McNutt, J. Weldon
由于可能造成伤害和死亡、疾病传播、分散机会或被排除在活动范围的关键区域之外，攻击性遭遇可能会产生重要的生活史后果。尽管如此，人们对它们的详细动态知之甚少，这主要是由于直接详细观察遭遇的困难。在这里，我们使用来自 11 个自由放养狼群的定制高分辨率 GPS 项圈的数据，描述了非洲野狗 (Lycaon pictus) 狼群间相遇的详细空间动态。平均而言，每个狼群大约每 7 周就会遇到另一个狼群，并且每年与邻居见面两次。令人惊讶的是，入侵者更有可能赢得遭遇战（通过在短期内保持更接近站点的位置赢得遭遇战的几率为 78.6%）。然而，在遭遇战后的短期（1 小时）内，入侵者确实倾向于比居民向自己的范围核心移动得更远，如果这被用来表明在遭遇战中失败，那么大多数（73.3%）的遭遇战都是居民获胜的。令人惊讶的是，相对群体大小对遭遇结果几乎没有影响，而且受伤的情况也很少（< 15% 的遭遇）。这些结果凸显了对涉及远离静态可防御食物资源的移动参与者的遭遇进行远程评分的难度。尽管在遭遇后，群体间的范围重叠减少了，但遭遇结果似乎并没有推动这一点，因为两个群体在遭遇后都改变了他们的范围。我们的结果表明，群体间遭遇的风险可能比之前建议的要低，并且似乎不会影响长期的运动和范围。意义陈述竞争者之间的直接攻击性遭遇是领地性的一个重要且潜在危险的方面。尽管如此，仍缺乏有关应对遭遇的运动的详细数据，尤其是大型哺乳动物。收集参赛者从不同方向离开比赛地点的观测数据在后勤上具有挑战性，而无线电项圈技术由于时间分辨率低，在这方面以前一直无效。我们通过使用定制的高分辨率 GPS 项圈克服了这些问题，结果表明，入侵的非洲野狗群体更有可能赢得群体间的遭遇（居民最初远离遭遇）。群体间的遭遇似乎只对行动产生短期影响，其结果对非洲野狗群体的长期活动模式没有明显影响。
Aggressive encounters may have important life history consequences due to the potential for injury and death, disease transmission, dispersal opportunities or exclusion from key areas of the home range. Despite this, little is known of their detailed dynamics, mainly due to the difficulties of directly observing encounters in detail. Here, we describe detailed spatial dynamics of inter-pack encounters in African wild dogs (Lycaon pictus), using data from custom-built high-resolution GPS collars in 11 freeranging packs. On average, each pack encountered another pack approximately every 7 weeks and met each neighbour twice each year. Surprisingly, intruders were more likely to win encounters (winning 78.6% of encounters by remaining closer to the site in the short term). However, intruders did tend to move farther than residents toward their own range core in the short-term (1 h) postencounter, and if this were used to indicate losing an encounter, then the majority (73.3%) of encounters were won by residents. Surprisingly, relative pack size had little effect on encounter outcome, and injuries were rare (< 15% of encounters). These results highlight the difficulty of remotely scoring encounters involving mobile participants away from static defendable food resources. Although inter-pack range overlap was reduced following an encounter, encounter outcome did not seem to drive this, as both packs shifted their ranges post-encounter. Our results indicate that inter-pack encounters may be lower risk than previously suggested and do not appear to influence long-term movement and ranging.Significance statementDirect aggressive encounters between competitors are an important and potentially dangerous aspect of territoriality. In spite of this, detailed data on movements in response to encounters are lacking, especially for large mammals. Collecting observational data on competitors leaving an encounter site in different directions is logistically challenging, and radiocollar technology has previously been ineffective in this regard due to low temporal resolution. We overcame these issues by using custom-built high-resolution GPS collars, showing that intruding African wild dog packs were more likely to win inter-pack encounters (residents initially moved further away from the encounter). Inter-pack encounters appeared to have only short-term impacts on movement, with their outcome having no discernible impact on the long-term ranging patterns of African wild dog packs.