Assortative pairing with respect to parasite load in the beetle Timarcha maritima (Chrysomelidae)

International audienceBecause of their effects on host reproductive behaviour, parasites are theoretically expected to create sometimes assortative mating among hosts, with heavily parasitized individuals pairing together and lightly parasitized ones pairing among themselves. We investigated the influence of protozoan gut parasites on the pairing pattern of the chrysomelid beetle Timarcha maritima. In the field, fecundity was negatively correlated with the parasite load of females, unpaired males were significantly more heavily infected than paired ones and, among pairs, males and females were matched for parasite load. Mate choice experiments in the laboratory showed that males have some ability to avoid heavily infected partners when given the choice between two females. Male competitiveness, measured as their mobility, was also negatively correlated with parasite load. These results indicate that parasite-related assortative pairing in this beetle could result from parasitized females being less fecund and parasitized males less competitive

Parasitoid Infection and Sexual Selection in the Beetle Timarcha maritima Perris (Coleoptera: Chrysomelidae)

International audienceWe investigated the influence of the hymenopteran parasitoid Perilitus sicheli Giard (Braconidae) on the pattern of mating and mate choice processes in the Chrysomelid beetle Timarcha maritima Perris. In the field, the prevalence of infection was higher in unpaired males and females than in paired individuals, although this result was significant only for males. The size of infected and uninfected individuals was not significantly different. The fecundity was significantly reduced by the infection in females. However, in experimental conditions males were unable to detect and to avoid infected females as sexual partners. We discuss the possible reasons for this absence of preference

Combination of marine and artificial freshwater habitats provides wintering Black-tailed Godwits with landscape supplementation

International audienceMigratory shorebirds, which have an energy-expensive lifestyle, must replenish their body reserves during winter to ensure their survival. Hence, birds have to select wintering habitats that provide the best net energy gain per unit of time while also considering possible disturbances such as predation risk, competition and resource depletion. Different foraging strategies can therefore emerge between species or individuals, such as focusing on one high-quality foraging habitat or making use of multiple habitats, resulting in contrasting distributions and movements patterns. By analysing the movements of 10 wintering Black-tailed Godwits Limosa limosa islandica through GPS-telemetry, our study aimed to understand and describe their spatiotemporal use of wetlands. Our results show that Black-tailed Godwits are flexible in terms of habitat use. All tracked godwits used more than one site during the survey period, with site shifts at both small and large spatial scales, and used multiple habitat types within sites. Indeed, although a dominant use of intertidal areas was observed, birds showed seasonal and daily habitat shifts by visiting inland marshes, saltpans and hunting ponds, with a habitat-specific activity rhythm. Finally, our results support the importance of the protected areas and the management of artificial wetland habitats to ensure the preservation of high-quality wintering areas for godwits