Escalante Ignacio, Elias Damian O
Department of Environmental Sciences, Policy, & Management University of California - Berkeley CA USA.
Present address: Behavioral & Molecular Ecology Group Department of Biological Sciences University of Wisconsin - Milwaukee Milwaukee WI USA.
Ecol Evol. 2021 Jul 14;11(15):10672-10685. doi: 10.1002/ece3.7879. eCollection 2021 Aug.
Finding shelter and surviving encounters with predators are pervasive challenges for animals. These challenges may be exacerbated after individuals experience bodily damage. Certain forms of damage arise voluntarily in animals; for instance, some taxa release appendages (tails, legs, or other body parts) as a defensive strategy ("autotomy"). This behavior, however, may pose long-term negative consequences for habitat use and survival. Additionally, these putative consequences are expected to vary according to the function of the lost body part. We tested the effects of losing different functional leg types (locomotor or sensory) on future habitat use and survival in a Neotropical species of harvestmen (Arachnida: Opiliones) that undergo frequent autotomy but do not regrow limbs. Daytime surveys revealed that both eight-legged harvestmen and harvestmen missing legs roosted in similar frequencies across habitats (tree bark, mossy tree, or fern), and perched at similar heights. Mark-recapture data showed that harvestmen that lost sensory legs roosted in tree bark less frequently, but on mossy trees more frequently. On the contrary, we did not observe changes in habitat use for eight-legged animals or animals that lost locomotor legs. This change might be related to sensory exploration and navigation. Lastly, we found that recapture rates across substrates were not affected by the type of legs lost, suggesting that leg loss does not impact survival. This potential lack of effect might play a role in why a defensive strategy like autotomy is so prevalent in harvestmen despite the lack of regeneration.
寻找庇护所并在与捕食者的遭遇中存活下来是动物普遍面临的挑战。在个体遭受身体损伤后，这些挑战可能会加剧。动物会主动产生某些形式的损伤；例如，一些分类群会释放附属肢体（尾巴、腿或其他身体部位）作为防御策略（“自切”）。然而，这种行为可能会对栖息地利用和生存造成长期的负面影响。此外，这些假定的后果预计会因失去的身体部位的功能而异。我们测试了失去不同功能类型的腿（运动腿或感觉腿）对一种新热带区的盲蛛（蛛形纲：盲蛛目）未来栖息地利用和生存的影响，这种盲蛛经常进行自切但不会再生肢体。白天的调查显示，八只腿的盲蛛和失去腿的盲蛛在不同栖息地（树皮、长满苔藓的树或蕨类植物）栖息的频率相似，且栖息高度也相似。标记重捕数据表明，失去感觉腿的盲蛛在树皮上栖息的频率较低，但在长满苔藓的树上栖息的频率较高。相反，我们没有观察到八只腿的动物或失去运动腿的动物在栖息地利用上有变化。这种变化可能与感觉探索和导航有关。最后，我们发现不同基质上的重捕率不受失去的腿的类型的影响，这表明腿的失去不会影响生存。这种潜在的无影响可能是自切这种防御策略在盲蛛中如此普遍的原因之一，尽管它们无法再生。
