Data from: When the mean no longer matters: developmental diet affects behavioral variation but not population averages in the house cricket (Acheta domesticus)

Despite recent progress in elucidating the genetic basis for behavioral variation, the effects of the developmental environment on the maintenance and generation of behavioral variation across multiple traits remain poorly resolved. We investigated how nutritional status during development affected behavioral variation and covariance between activity in an open field test and response to cues of predator presence in the house cricket (Acheta domesticus). We provided 98 juvenile crickets with either a high or low quality diet during development, throughout which we measured body mass, activity in a modified open-field, and response to predator excreta twice every week for 3 weeks. Diet quality affected growth rate but not average activity or response to cues of predator presence, nor the correlation between the 2. However, repeatability (τ) in response to cues of predator presence was reduced by 0.24 in individuals exposed to the high quality diet versus the low quality diet. Larger individuals also increased their response to predator cues when reared on a high quality diet, suggesting negative feedbacks between growth rate and antipredator behaviors. Our results also indicate that changes in the developmental environment are not sufficient to collapse behavioral syndromes, suggesting a genetic link between activity and predator cue response in house crickets, and that nutritional stress early in life can lead to more consistent behavioral responses when individuals faced predatory threats. Our results demonstrate that subtle differences in the quality of the environment experienced early in life can influence how individuals negotiate behavioral and life-history trade-offs later in life.

尽管目前在阐明行为变异的遗传基础方面已取得一定进展，但发育环境对多性状行为变异的维持与产生的影响，仍未得到充分解析。我们以家蟋蟀（Acheta domesticus）为研究对象，探究了发育阶段的营养状况对其行为变异的影响，以及改良旷场试验（modified open-field）中的活动水平与捕食者存在线索响应之间的协变关系。我们为98只幼年家蟋蟀在发育阶段提供高营养或低营养日粮，并在为期3周的实验中，每周两次测量其体重、改良旷场中的活动水平，以及对捕食者排泄物的响应情况。日粮营养水平仅影响了蟋蟀的生长速率，并未改变其平均活动水平、捕食者线索响应强度，亦未改变二者间的相关性。不过，相较于低营养日粮组，饲喂高营养日粮的个体，其对捕食者线索响应的重复率（τ）降低了0.24。当日粮营养水平较高时，体型更大的个体对捕食者线索的响应强度会提升，这提示生长速率与反捕食行为间存在负反馈调控。本研究结果还表明，发育环境的改变并不足以瓦解行为综合征（behavioral syndromes），这提示家蟋蟀的活动能力与捕食者线索响应之间存在遗传关联；同时还发现，生命早期的营养胁迫，会让个体在面临捕食威胁时展现出更稳定的行为响应。我们的研究证实，生命早期经历的环境细微差异，能够影响个体在后续生命阶段中如何协调行为与生活史的权衡策略。