Lagos Patricio A, Herberstein Marie E
Macquarie University, Sydney, Australia.
Macquarie University, Sydney, Australia.
Physiol Behav. 2017 May 1;173:110-115. doi: 10.1016/j.physbeh.2017.02.002. Epub 2017 Feb 3.
The non-consumptive effects of predation contribute to reduce preys' fitness. In this way, predation imposes a cost to animals, not only through direct consumption, but also as an energetic cost. One way used to estimate this cost in the past has been to measure the production of CO to estimate the change in metabolic rate because of predation. It has been proposed that this change is mediated by the insect stress neurohormone octopamine. Here we study the change in metabolic rate of the black field cricket (Teleogryllus commodus), and how the production of CO varies when a chemical cue from a sympatric predator is added. We hypothesised that after the addition of a predatory cue, the metabolic rate will increase. Moreover, since the pressure of predation is stronger on females, we propose that females will have a greater increase in the CO produce as consequence of the added cues from the predator. Our results confirmed our first hypothesis, showing an almost two-fold increase in CO when the predatory cue was added. However, males were the ones that showed a greater increase, in opposition to our second hypothesis. We put these results in the context of the escape theory and, in particular, the "landscape of fear" hypothesis. Also, because the timing between the increase of metabolic rate we measure here and the release of octopamine reported in previous studies do not match, we reject the idea that octopamine causes the increase in metabolism.
捕食的非消费性影响会降低猎物的适应性。通过这种方式，捕食不仅通过直接消耗，还作为一种能量成本，给动物带来代价。过去用于估计这种成本的一种方法是测量二氧化碳的产生量，以估计由于捕食导致的代谢率变化。有人提出这种变化是由昆虫应激神经激素章鱼胺介导的。在这里，我们研究了黑田蟋（Teleogryllus commodus）的代谢率变化，以及当添加来自同域捕食者的化学信号时，二氧化碳的产生量如何变化。我们假设添加捕食信号后，代谢率会增加。此外，由于捕食压力对雌性更强，我们提出雌性由于捕食者添加的信号，二氧化碳产生量的增加会更大。我们的结果证实了我们的第一个假设，即添加捕食信号后，二氧化碳产生量几乎增加了两倍。然而，与我们的第二个假设相反，雄性的增加幅度更大。我们将这些结果置于逃逸理论的背景下，特别是“恐惧景观”假说中。此外，由于我们在此测量的代谢率增加与先前研究中报道的章鱼胺释放之间的时间不一致，我们拒绝章鱼胺导致代谢增加的观点。
