Owens Avalon Celeste Stevahn, Meyer-Rochow Victor Benno, Yang En-Cheng
Department of Biology, Tufts University, Medford, Massachusetts, United States of America.
Department of Genetics and Physiology, Oulu University, Oulu, Finland.
PLoS One. 2018 Feb 7;13(2):e0191576. doi: 10.1371/journal.pone.0191576. eCollection 2018.
Urbanization can radically disrupt natural ecosystems through alteration of the sensory environment. Habitat disturbances are predicted to favor behaviorally flexible species capable of adapting to altered environments. When artificial light at night (ALAN) is introduced into urban areas, it has the potential to impede reproduction of local firefly populations by obscuring their bioluminescent courtship signals. Whether individual fireflies can brighten their signals to maintain visibility against an illuminated background remains unknown. In this study, we exposed male Aquatica ficta fireflies to diffused light of varying wavelength and intensity, and recorded their alarm flash signals. When exposed to wavelengths at or below 533 nm, males emitted brighter signals with decreased frequency. This is the first evidence of individual-level light signal plasticity in fireflies. In contrast, long wavelength ambient light (≥ 597 nm) did not affect signal morphology, likely because A. ficta cannot perceive these wavelengths. These results suggest long wavelength lighting is less likely to impact firefly courtship, and its use in place of broad spectrum white lighting could augment firefly conservation efforts. More generally, this study demonstrates benefits of bioluminescent signal plasticity in a "noisy" signaling environment, and sheds light on an important yet understudied consequence of urbanization.
城市化能够通过改变感官环境从根本上扰乱自然生态系统。据预测，栖息地干扰有利于那些能够适应环境变化的行为灵活的物种。当夜间人造光（ALAN）引入城市地区时，它有可能通过遮蔽萤火虫的生物发光求偶信号来阻碍当地萤火虫种群的繁殖。个体萤火虫是否能够增强它们的信号以在光照背景下保持可见性仍然未知。在这项研究中，我们将雄性拟水萤暴露于不同波长和强度的漫射光下，并记录它们的警报闪光信号。当暴露于533纳米及以下波长时，雄性萤火虫发出更亮的信号且频率降低。这是萤火虫个体水平光信号可塑性的首个证据。相比之下，长波长环境光（≥597纳米）不会影响信号形态，可能是因为拟水萤无法感知这些波长。这些结果表明，长波长照明对萤火虫求偶的影响较小，使用长波长照明代替广谱白色照明可以加强萤火虫的保护工作。更普遍地说，这项研究证明了在“嘈杂”的信号环境中生物发光信号可塑性的益处，并揭示了城市化一个重要但尚未充分研究的后果。
