Pre-copulatory reproductive behaviours are preserved in Drosophila melanogaster infected with bacteria

Reproduction and immunity are crucial traits that determine an animal’s fitness. Terminal investment hypothesis predicts that reproductive investment should increase in the face of a mortality risk caused by infection. However, due to competitive allocation of energetic resources, individuals fighting infections are expected to decrease reproductive efforts. While there is evidence for both hypotheses, the factors that determine the choice between these strategies are poorly understood. Here, we assess the impact of bacterial infection on pre-copulatory behaviours in the fruit fly Drosophila melanogaster. We found that male flies infected with six different bacteria, including pathogenic and non-pathogenic strains, show no significant differences in courtship intensity and mating success. Similarly, bacterial infections did not affect sexual receptivity in female flies. Our data suggest that pre-copulatory reproductive behaviours remain preserved in infected animals, despite the huge metabolic cost of infection.

The effect of male-male competition and ornament size on mean and variance of courtship intensity towards heterospecific and conspecific females

Discrimination between hetero- and conspecifics is the elementary choice an individual performs when searching for potential mates. The level of selectivity and strength of species discrimination is modified by variance in the quality of females, level of the male’s reproductive investment, mate search costs, and the competitive environment. The effect of the competitive environment on both species discrimination and conspecific mate choice has seldom been studied simultaneously. We experimentally manipulated territorial competition ofCalopteryx splendensdamselfly males in the wild, and asked two questions. First, does increased competition influence the territorial males’ responses towards introduced heterospecificC. virgofemales. The effect of the size of the territorial males’ sexual ornaments (wing spot) on their responses towards females was also investigated. Second, does increased competition influence the territorial males’ response towards conspecific females? The effect of the size of the territorial males ornament was again investigated. The mean level of response towards heterospecific females did not change between the control (i.e., no competitors presented) and the competition (i.e., two competitors presented) treatments, but the variance of responses towards heterospecifics was greater in the competition treatment. The territorial males’ responses towards conspecific females did not change between control and competition treatments. These results indicate individual differences in the behavior of males towards heterospecifics when territorial competition was experienced. The observed pattern of discrimination might be adaptive when overall reproductive success is considered.

Familiarity with a female does not affect a male’s courtship intensity in garter snakes Thamnophis sirtalis parietalis

In many animal species, males direct more intense courtship towards females they have not previously encountered, than towards females with which they have previously mated. To test the factors responsible for this “Coolidge Effect”, we need studies on a wide range of taxa – including those with mating systems in which we would not expect (based on current theory) that such an effect would be evident. The Coolidge Effect has been documented in several lizard species, but has not been looked for (and would not be expected) in snakes. We conducted experimental trials with red-sided garter snakes Thamnophis sirtalis pa-rietalis at a communal den in Manitoba, to see whether previous exposure to a female (either courting, or courting plus mating) modified male mate choice or courtship intensity. In keeping with prediction from theory (but contrary to an early anecdotal report), male garter snakes did not modify their courtship behaviour based upon their familiarity (or lack thereof) with a specific female. At least in large courting aggregations, male snakes may maximize their fitness by basing mate-choice upon immediate attributes of the female (body size, condition, mated status) and the intensity of competition (numbers and sizes of rival males) rather than information derived from previous sexual encounters.

Love, Religion and Power in the Making of Marriages in Early Nineteenth-Century Rural Industrial Lancashire

This article addresses the relative dearth of work on courtship and marriage motivations for early nineteenth-century England. Focusing on rural-industrial Lancashire, the article draws on a rare conjunction of sources: an autobiography, a series of love-letters and letters from friends, relating to the nascent textile entrepreneur David Whitehead and his intended wife Betty Wood. Triangulating these sources suggests that some of the seemingly dominant influences on courtship and marriage seen in other studies, such as the economic status of partners, family and kin, had little part in this drama. Rather, issues of love, destiny and, above all, religious suitability dictated the pace, content and outcome of the courtship process. Against this backdrop, it was Betty Wood, rather than David Whitehead, who held the levers of power in the courtship. The article also explores other aspects of courtship, most especially the relationship between courtship intensity/fragility and the spatial dynamics of the marriage market.

Courtship displays and mounting calls are honest, condition-dependent signals that influence mounting success in Hermann's tortoises

Like other terrestrial tortoises, the courtship behaviour of Hermann's tortoises (Testudo hermanni Gmelin, 1789) is based on a multiple signalling system that involves visual, olfactory, tactile, and acoustic signals. In this study, we analysed relationships between male morphology, hematological profile, courtship intensity, vocalizations, and mounting success in Hermann's tortoises breeding in semi-natural enclosures to investigate the effects of male condition on signals exhibited during courtship and on their mounting success. Results showed that mounting success of Hermann's tortoise males was positively affected by the number of sexual interactions/h, number of bites given to the female during interactions, and by call rate and frequency-modulation range. Call rate, frequency-modulation range, and number of sexual interaction/h increased with hematocrit value, while number of bites given to females decreased with leukocyte concentration. In conclusion, courtship signals exhibited by Hermann's tortoise males, including vocalizations, reliably reveal different components of male condition, and females may use these multiple traits to choose high-quality partners. This is the first study documenting the condition-dependent nature of tortoise courting signals and their effect on male mounting success.