Male Sexual Preference for Female Swimming Activity in the Guppy (Poecilia reticulata)

Abstract

Mate choice that is based on behavioural traits is a common feature in the animal kingdom. Using the Trinidadian guppy, a species with mutual mate choice, we investigated whether males use female swimming activity-a behavioural trait known to differ consistently among individuals in many species-as a trait relevant for their mate choice. In the first experiment, we assessed male and female activity in an open field test alone (two repeated measures) and afterwards in heterosexual pairs (two repeated measures). In these pairs, we simultaneously assessed males' mating efforts by counting the number of sexual behaviours (courtship displays and copulations). Male and female guppies showed consistent individual differences in their swimming activity when tested both alone and in a pair, and these differences were maintained across both test situations. When controlling for male swimming behaviour and both male and female body size, males performed more courtship displays towards females with higher swimming activity. In a second experiment, we tested for a directional male preference for swimming activity by presenting males video animations of low- and high-active females in a dichotomous choice test. In congruence with experiment 1, we found males to spend significantly more time in association with the high-active female stimulus. Both experiments thus point towards a directional male preference for higher activity levels in females. We discuss the adaptive significance of this preference as activity patterns might indicate individual female quality, health or reproductive state while, mechanistically, females that are more active might be more detectable to males as well.

Keywords: Poecilia reticulata; animal personality; male mate choice; mating preferences; swimming activity.

Figure 1

Schematic overview of the experimental timeline for experiments 1 (A) and 2 (B).

Figure 2

(A) Distance moved by females. Mean distances for both trials (1st and 2nd) are shown as well as for the treatments (female alone or with a male partner). (B) Consistency in female swimming activity across treatments. A scatter plot with individual-level error bars and a linear line of best fit (with 95% CI, dotted lines) is shown for female distances moved in an open field arena both alone and with a male partner. Error bars represent standard error (SEM) (A) and SD (B).

Figure 3

Male sexual activity (sum of courtship displays and copulation attempts) and female swimming activity (distance moved in an open field tank with a male partner). The regression line refers to the final generalized linear mixed model (GLMM) predictions (with 95% CI). Error bars represent SD.

Figure 4

Results of dichotomous mate choice tests to assess directional mating preferences of male guppies for female swimming activity. The mean (±SE) times males spent near fast (2.7 cm/s) and slow (0.7 cm/s) moving female animations are shown. An asterisk indicates significant difference (p < 0.05) in paired-samples t-test.