Hale Robin, Colombo Valentina, Hoak Molly, Pettigrove Vin, Swearer Stephen E
School of BioSciences University of Melbourne Parkville Victoria Australia.
Centre for Aquatic Pollution Identification and Management Parkville Victoria Australia.
Ecol Evol. 2019 Apr 10;9(9):5512-5522. doi: 10.1002/ece3.5148. eCollection 2019 May.
Theory predicts that animals should prefer habitats where their fitness is maximized but some mistakenly select habitats where their fitness is compromised, that is, ecological traps. Understanding why this happens requires knowledge of the habitat selection cues animals use, the habitats they prefer and why, and the fitness costs of habitat selection decisions. We conducted experiments with a freshwater insect, the non-biting midge to ask: (a) whether females respond to potential oviposition cues, (b) to explore whether oviposition is adaptive in relation to metal pollution and conductivity, and (c) whether individuals raised in poor quality sites are more likely to breed in similarly poor locations. We found the following: (a) females responded to some cues, especially conductivity and conspecifics, (b) females preferred sites with higher concentrations of bioavailable metals but suffered no consequences to egg/larval survival, (c) females showed some avoidance of high conductivities, but they still laid eggs resulting in reduced egg hatching, larval survival, and adult emergence, and (d) preferences were independent of natal environment. Our results show that is susceptible to ecological traps, depending on life stage and the relative differences in conductivities among potential oviposition sites. Our results highlight that (a) the fitness outcomes of habitat selection need to be assessed across the life cycle and (b) the relative differences in preference/suitability of habitats need to be considered in ecological trap research. This information can help determine why habitat preferences and their fitness consequences differ among species, which is critical for determining which species are susceptible to ecological traps.
理论预测,动物应该偏好能使其适合度最大化的栖息地,但有些动物会错误地选择适合度受损的栖息地,即生态陷阱。要理解这种情况发生的原因,需要了解动物用于栖息地选择的线索、它们偏好的栖息地及原因,以及栖息地选择决策的适合度成本。我们用一种淡水昆虫——摇蚊进行了实验,以探究:(a)雌性是否对潜在的产卵线索有反应;(b)探讨产卵在金属污染和电导率方面是否具有适应性;(c)在质量较差的地点饲养的个体是否更有可能在同样较差的地点繁殖。我们发现:(a)雌性对一些线索有反应,尤其是电导率和同种个体;(b)雌性偏好生物可利用金属浓度较高的地点,但卵/幼虫的存活没有受到影响;(c)雌性对高电导率有一定的回避,但它们仍然产卵,导致卵孵化率、幼虫存活率和成虫羽化率降低;(d)偏好与出生环境无关。我们的结果表明,根据生命阶段以及潜在产卵地点之间电导率的相对差异,摇蚊易受生态陷阱影响。我们的结果强调:(a)需要在整个生命周期内评估栖息地选择的适合度结果;(b)在生态陷阱研究中需要考虑栖息地偏好/适宜性的相对差异。这些信息有助于确定为什么不同物种的栖息地偏好及其适合度后果存在差异,这对于确定哪些物种易受生态陷阱影响至关重要。