Male guppies differ in daily frequency but not diel pattern of display under daily light changes
Sexually signalling animals must trade off the benefits of attracting mates with the consequences of attracting predators. For male guppies, predation risk depends on their behaviour, colouration, environmental conditions and changing intensity of predation throughout the day. Theoretically, this drives diel patterns of display behaviour in native Trinidadian populations, where males display more under low-light conditions when their most dangerous predator is less active. Here, we observed Australian guppies in a laboratory setting to investigate their diel display pattern, and if this pattern is controlled by ambient light intensity. We also quantified individual variation in both the daily frequency and diel pattern of displays, and if such variation relates to body size, colouration and a non-sexual behaviour. Under a typical daily light regime, male guppies displayed mostly in the first hour of observation. Extending the duration of dawn-like lighting, however, resulted in an extended period of high display, demonstrating that light intensity per se is an important cue for this behaviour. These findings mirror those obtained for Trinidadian populations, suggesting that male courtship timing is likely shaped by broad, potentially generalizable features of guppy ecology. The effect of acclimation to captive conditions on male behaviour is also discussed. Whereas the temporal pattern of display appeared consistent, individuals varied in their daily display frequency, and this was correlated with variation in colour phenotype and a measure of non-sexual risk acceptance behaviour. Such relationships pose promising avenues for integrating behavioural and sensory ecology with contemporary work on behavioural syndromes and animal personality.
To limit the costs of their conspicuous colour patterns, male guppies should alter their behaviour to avoid predation. However, our understanding of how different individuals deal with this problem is lacking. Following individuals in the laboratory, we demonstrated individual variation in the daily frequency of male displays, and this was correlated with variation in colour phenotypes and non-sexual behaviour. However, all male guppies displayed more in the early hours of the day and extending the period of low lighting also extended this period of elevated display. These findings replicate and expand experiments on native populations, suggesting that male courtship timing is likely shaped by broad, potentially generalizable features of guppy ecology.
KeywordsAnimal behaviour Mating behaviour Light environment Trade-off Sexual signal Colour
The authors warmly thank Andrea Pilastro, David Reznick, Katarina Stuart, Sally Dupont and two anonymous referees for providing constructive comments on the manuscript.
Financial support was provided by the Australian Research Council via Discovery-Projects grant DP160103668.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
All procedures performed in studies involving animals were approved by and in accordance with the guidelines outlined by the Macquarie University Animal Ethics committee (Approval No. ARA 2017/035-12).
We are grateful to the Queensland Government Department of National Parks, Sport and Racing for granting permission to sample guppies under permit number WITK18612917.
- Brooks R, Endler JA (2001) Female guppies agree to differ: phenotypic and genetic variation in mate-choice behaviour and the consequences for sexual selection. Evolution 55:1644–1655. https://doi.org/10.1111/j.0014-3820.2001.tb00684.x CrossRefPubMedGoogle Scholar
- Hoffmann T (2017). SunCalc, https://www.suncalc.org/
- Houde AE (1997) Sex, color, and mate choice in guppies. Princeton University Press, PrincetonGoogle Scholar
- Kotrschal A, Lievens EJ, Dahlbom J, Bundsen A, Semenova S, Sundvik M, Maklakov AA, Winberg S, Panula P, Kolm N (2014) Artificial selection on relative brain size reveals a positive genetic correlation between brain size and proactive personality in the guppy. Evolution 68:1139–1149. https://doi.org/10.1111/evo.12341 CrossRefPubMedPubMedCentralGoogle Scholar
- R Development Core Team (2017) R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria https://www.R-project.org
- Rice WR (1989) Analyzing tables of statistical tests. Evolution 43:223–225. https://doi.org/10.1111/j.1558-5646.1989.tb04220.x CrossRefGoogle Scholar