Hassan Wrya, Kobak Jarosław, Czarnecka Magdalena
Department of Ecology and Biogeography, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, Lwowska 1, 87-100 Toruń, Poland.
Department of Invertebrate Zoology and Parasitology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, Lwowska 1, 87-100 Toruń, Poland.
Curr Zool. 2024 Oct 3;71(4):432-439. doi: 10.1093/cz/zoae061. eCollection 2025 Aug.
Artificial light at night (ALAN) is a common anthropogenic disturbance, which alters animal behavior. However, little is known about the impact of the spectral composition of ALAN and co-occurring predation risk on the behavior of aquatic organisms. We experimentally investigated how ALAN of different spectra (cool white LED and HPS light) affects the behavior and foraging of (Amphipoda) on chironomid prey, both as a single stressor and in combination with an olfactory predation cue. Gammarids exposed to ALAN in the absence of predation cues consumed less, compared with darkness, mainly due to their lower activity. Moreover, gammarids showed a stronger response to LED light, spending more time in the shelter and increasing prey handling time in this treatment. The addition of predation cues did not enhance the negative impact of ALAN on the foraging success. Gammarids maintained similar consumption levels as in the ALAN treatment without predation cues and in darkness with predation cues. However, gammarids in LED light altered their behavior in response to predation threat: they decreased prey handling time and consumed prey faster, which may have compensated for the higher food demand in stressful conditions. They also tended to exhibit risky behavior, leaving the shelter and moving towards the lit area, presumably to escape and avoid the combined effects of light and predation cues. Therefore, when assessing the effects of ALAN on organisms, light quality and co-occurring biotic factors should be considered, as predator pressure is common in natural environments.
夜间人造光（ALAN）是一种常见的人为干扰因素，它会改变动物的行为。然而，关于ALAN的光谱组成以及同时存在的捕食风险对水生生物行为的影响，我们却知之甚少。我们通过实验研究了不同光谱的ALAN（冷白色发光二极管和高压钠灯）如何影响双甲藻（Amphipoda）对摇蚊猎物的行为和觅食情况，这两种情况分别作为单一应激源以及与嗅觉捕食线索相结合的情况。在没有捕食线索的情况下，暴露于ALAN的双甲藻与处于黑暗环境相比，进食量更少，这主要是因为它们的活动水平较低。此外，双甲藻对发光二极管光表现出更强的反应，在这种处理方式下，它们在遮蔽处停留的时间更长，并且增加了处理猎物的时间。捕食线索的添加并没有增强ALAN对觅食成功率的负面影响。双甲藻在有捕食线索的ALAN处理中以及在有捕食线索的黑暗环境中的进食水平保持相似。然而，处于发光二极管光环境中的双甲藻会根据捕食威胁改变它们的行为：它们减少了处理猎物的时间并且更快地消耗猎物，这可能补偿了压力环境下更高的食物需求。它们还倾向于表现出冒险行为，离开遮蔽处并朝着有光的区域移动，大概是为了逃避和避免光与捕食线索共同产生的影响。因此，在评估ALAN对生物体产生的影响时，应考虑光的质量以及同时存在的生物因素，因为在自然环境中捕食压力是普遍存在的。
