Rosa Márta E, Barta Zoltán, Kosztolányi András
Department of Ecology, University of Veterinary Medicine Budapest, Budapest, Hungary.
MTA-DE Behavioural Ecology Research Group, Department of Evolutionary Zoology and Human Biology, University of Debrecen, Debrecen, Hungary.
Behav Processes. 2018 Apr;149:65-71. doi: 10.1016/j.beproc.2018.02.004. Epub 2018 Feb 8.
In resident-intruder contests, residents are expected to win more often than intruders unless the intruder has significantly higher competitive ability that is often determined by its size. Therefore, small intruders are expected to be less motivated to engage in contests than large ones and intruder size is predicted to have a positive relationship with the duration and escalation of the encounters. In a field experiment we tested these hypotheses in Lethrus apterus, a biparental beetle breeding in underground tunnels, by placing either a small or a large male in front of a tunnel occupied by a resident male. In agreement with our predictions residents won most of the encounters. Small intruders were less willing to engage in a contest and were less successful in their takeover attempts than large intruders. Contrary to many studies however, the duration and escalation (measured by the occurrence and latency of the different contest stages) of the fight in front of the burrow did not differ between the two intruder size categories. These findings suggest that in this species, small and large intruders adjust their prior decisions to their competitive abilities but once a fight started, they behave similarly during the contest.
在领地所有者与入侵者的对抗中，领地所有者通常比入侵者获胜的次数更多，除非入侵者具有明显更强的竞争能力，而这种能力通常由其体型决定。因此，预计小型入侵者比大型入侵者参与对抗的积极性更低，并且预计入侵者的体型与对抗的持续时间和激烈程度呈正相关。在一项野外实验中，我们以无翅豆象（一种在地下隧道中繁殖的双亲甲虫）为对象，通过在一只领地雄性甲虫占据的隧道前放置一只小型或大型雄性甲虫，来检验这些假设。与我们的预测一致，领地所有者赢得了大多数对抗。小型入侵者比大型入侵者更不愿意参与对抗，并且在接管尝试中也不太成功。然而，与许多研究相反，洞穴前战斗的持续时间和激烈程度（通过不同对抗阶段的发生情况和潜伏期来衡量）在两种不同体型的入侵者之间并无差异。这些发现表明，在这个物种中，小型和大型入侵者会根据自身竞争能力调整其先前的决策，但一旦战斗开始，它们在对抗过程中的行为表现相似。
