University of Oulu

Borshagovski, AM., Saari, P., Lehtonen, T.K. et al. When night never falls: female sexual signalling in a nocturnal insect along a latitudinal gradient. Behav Ecol Sociobiol 74, 153 (2020).

When night never falls : female sexual signalling in a nocturnal insect along a latitudinal gradient

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Author: Borshagovski, Anna-Maria1,2; Saari, Paulus3; Lehtonen, Topi K.1,2;
Organizations: 1Ecology and Genetics Research Unit, University of Oulu, PO Box 3000, FI-90014, Oulu, Finland
2Tvärminne Zoological Station, University of Helsinki, J.A. Palménin tie 260, FI-10900, Hanko, Finland
3Nano and Molecular Systems Research Unit, Biophysics group, University of Oulu, PO Box 3000, FI-90014, Oulu, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 0.8 MB)
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Language: English
Published: Springer Nature, 2020
Publish Date: 2021-01-19


The environment can play an important role in animal communication by affecting signal transmission and detection. Variation in the signalling environment is expected to be especially pronounced in widely distributed species, potentially affecting how their signals are detected. Such environmental variability is presumably relevant for sedentary females of a nocturnal capital breeder, the European common glow-worm (Lampyris noctiluca), which produce green light during the night to attract flying males to mate. Being widely distributed in Europe, glow-worm populations are exposed to both rapidly descending, darker summer nights in the south, and slowly dimming, brighter summer nights further north, with the latter potentially posing challenges to the visibility of the female glow. To test how female signalling is affected by latitude, we sampled glowing females during summer nights along a latitudinal gradient in Finland, Northern Europe, and used a novel apparatus to measure the intensity and peak wavelength (hue/colour) of their glow. Surprisingly, females at higher latitudes, similar to those at lower latitudes, were commonly glowing during the brightest (and hence the shortest) nights of the year. Females also glowed brighter in more northern areas, partly due to their larger body size, whereas the colour of their glow was not associated with latitude. Since females glow even during midsummer, independent of latitude, the increase in glow intensity at higher latitudes presumably serves to maintain signal visibility in brighter signalling conditions. Overall, these findings highlight the influence of environmental conditions on the evolution of sexual signals, especially in the context of species distribution range.

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Series: Behavioral ecology and sociobiology
ISSN: 0340-5443
ISSN-E: 1432-0762
ISSN-L: 0340-5443
Volume: 74
Issue: 12
Article number: 153
DOI: 10.1007/s00265-020-02927-9
Type of Publication: A1 Journal article – refereed
Field of Science: 1181 Ecology, evolutionary biology
Funding: Open access funding provided by University of Oulu including Oulu University Hospital. The work was funded by the Academy of Finland (grant number #294664 to AK, TKL and AMB) and Emil Aaltonen Foundation (AMB).
Academy of Finland Grant Number: 294664
Detailed Information: 294664 (Academy of Finland Funding decision)
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