Biology subjects

Seymoure, B.

Publications and source records attributed to Seymoure, B..

2 recordsLinked to original sources

bioRxiv2026

Organismal responses to artificial light at night in terrestrial ecosystems vary across lunar cycles

Globally, nocturnal lightscapes are now determined by both moonlight and light pollution, or artificial light at night (ALAN). Organisms respond both to changes in moonlight across lunar cycles and to alterations in light conditions due to artificial light. The interaction of natural and artificial light is a critical aspect to incorporate into our understanding of how crepuscular and nocturnal ecology is altered in anthropogenically-modified landscapes. In this manuscript we review the rapidly expanding body of research on ecological impacts of ALAN to (1) assess patterns of lunar data inclusion and (2) summarize documented interactions of moonlight and ALAN. Three-fourths (72%) of 379 papers reviewed did not incorporate moonlight into their statistical analyses and experimental design. Only 12% directly investigated interaction effects of moonlight and ALAN. However, 70% of these studies reported an interactive effect. Considering this stark contrast, as a precursor to our literature review, we present an overview of moonlight and the lunar cycle for biologists. The overarching trend emerging from the literature is that biological impacts of ALAN decrease with increasing moonlight, although the opposite is true in some cases. After summarizing the literature, we present general hypotheses regarding the interaction of the lunar cycle and ALAN. These hypotheses consider the different forms of ALAN encountered by organisms (i.e. skyglow and light sources) and account for the influence of cloud cover. Finally, we suggest best practices for incorporating moonlight into future research on biological impacts of ALAN.

ecology↗

bioRxiv2023

Male behavior in a swallowtail butterfly (Battus philenor) ensures directional iridescent sexual signal is visible to females during courtship

Iridescent colors in animals may vary with the arrangement of the observer and the light source relative to the animal. When these highly directional colors are used as signals, there may be transmission problems for senders in that the perception of the signal by intended receivers can be greatly affected by the spatial arrangement of the sender, receiver, and sources of contributing light. One potential solution to this problem is for senders to behave in a manner that arranges the positions of sender, light source, and receiver to enhance signal perception by the receiver. We tested this idea by describing the structure of courtship behavior of males of the Pipevine Swallowtail (Battus philenor) butterfly and analyzing its consequences for the female detection of the males iridescent sexual signal which is used in mate choice by females. During courtship, males perform a swoop maneuver that brings their dorsal hindwing from below to directly in front of the female. Several swoops in rapid succession occur in aerial courtships that lead to copulation. We measured under solar radiation the radiance of the males dorsal hindwing as seen by the female during a swoop. Regardless of how the males swoop path is oriented relative to the sun, there will be a brief, bright, and saturated flash of blue visible to the female. Our results support the conclusion that male swoops enhance the visibility of the males iridescent color signal to the female during courtship.

animal behavior and cognition↗