ABSTRACT: The individuals of many species shift habitats at different stages in their lives. Sometimes, these habitat shifts coincide with an ontogenetic transition. These ontogenetic habitat shifts can allow species to access nutritional resources, avoid conspecific aggression or predation, or secure breeding opportunities when it is advantageous to do so. The Kermadec Islands giant limpet Scutellastra kermadecensis is a protandrous hermaphrodite endemic to Rangitāhua, the Kermadec Islands. These limpets have an unusual habit whereby small limpets (piggies) piggy-back on the shells of larger individuals rather than living on the rocky substrate. We investigated whether the ontogenetic habitat shift between the piggy-backing and rock-attached limpets was determined by the availability of free space on the rock or whether the ontogenetic habitat shift was a response to the properties of the surrounding limpet population. We found that the available rock space did not influence the size at which an individual transitioned from being a piggy to being rock-attached. Furthermore, larger rock-attached limpets were more likely to have piggies, they had more piggies, and the piggies were larger. Overall, our results suggest that Kermadec giant limpets are motivated to piggy-back by the properties of the social environment rather than space constraints. The piggy-backing behaviour may be a mechanism to avoid bulldozing by larger limpets, to access grazing opportunities on the shells of larger limpets, and/or to monopolise breeding opportunities with larger rock-attached females. We discuss the repercussions of this life-history strategy for this extremely range-restricted species, with reference to how these populations may be monitored and maintained.

中文翻译：

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社会环境介导范围有限的巨型帽贝的栖息地转移

摘要：许多物种的个体在其生活的不同阶段转移栖息地。有时，这些栖息地的变化与个体发育的转变相吻合。这些自生的栖息地转移可以使物种获得营养资源，避免同种侵略或掠食，或在有利时确保繁殖机会。克马德克群岛的巨型帽贝Scutellastra kermadecensis是克马德克群岛兰吉塔瓦（Rangitāhua）的一种原产于雌雄同体的两性人。这些帽贝有一个不寻常的习惯，即小帽贝（小猪）背负于较大个体的壳上，而不是生活在多岩石的基质上。我们调查了背piggy和附有岩石的贝类之间的个体发生栖息地转移是由岩石上自由空间的可用性决定的，还是个体发生的栖息地转移是对周围贝类种群特性的响应。我们发现，可用的岩石空间不会影响个人从小猪过渡到附着在岩石上的大小。此外，较大的附有岩石的帽贝更容易生猪，它们的生猪更多，而生猪也更大。全面的，我们的研究结果表明，Kermadec巨大的帽贝是受社会环境的属性而不是空间限制的驱使而背负的。背piggy行为可能是一种机制，它可以避免较大的贝类推土机，获得较大的贝类壳上的放牧机会和/或垄断与较大的附有岩石的雌性的繁殖机会。我们讨论了这种生活史策略对这一极受范围限制的物种的影响，并参考了如何监控和维护这些种群。和/或垄断附有较大结石的雌性的繁殖机会。我们讨论了这种生活史策略对这一极受范围限制的物种的影响，并参考了如何监控和维护这些种群。和/或垄断附有较大结石的雌性的繁殖机会。我们讨论了这种生活史策略对这一极受范围限制的物种的影响，并参考了如何监控和维护这些种群。