Search

Abstract Babesia sp. YLG has recently been described in Yellow-legged gull (Larus michahellis) chicks and belongs to the Peircei clade in the new classification of Piroplasms. Here, we studied Babesia sp. YLG vectorial transmission by ticks in the simplified environment of a single seabird breeding colony where the Yellow-legged gull is the sole vertebrate host, Ornithodoros maritimus (syn. Alectorobius maritimus) the sole tick species, and Babesia sp. YLG is the only blood parasite species detected in chicks of the colony. We collected ticks over four years, maintained certain individuals through moulting or oviposition, and dissected fresh ticks to isolate different organs and test for the presence of the parasite using molecular assays. We report the first strong evidence of a Piroplasmidae transmitted by a soft tick. Indeed, Babesia sp. YLG DNA was detected in the salivary glands of nymphs, females and males, a necessary organ to infect for transmission to a new vertebrate host. Parasite DNA was also found in tick ovaries, which could indicate possible transovarial transmission. Our detection of Babesia sp. YLG DNA in several male testes and in endospermatophores, and notably in a parasite-free female (uninfected ovaries and salivary glands), raise the interesting possibility of sexual transmission from infected males to uninfected females. Future work in this system will now need to focus on the degree to which the parasite can be maintained locally by ticks and the epidemiological consequences of infection for both O. maritimus and its avian host.

Breeding birds in agricultural landscapes have declined considerably since the 1950s and the beginning of agricultural intensification in Europe. Given the increasing pressure on agricultural land, it is necessary to identify conservation measures that consume little productive land. We tested the compensation hypothesis which states that field margins may represent substitute habitats for bird species in agricultural wetlands. We monitored bird species in 86 crop fields in rice paddy landscapes of Camargue (southern France), a wetland of international importance for birds. We investigated whether the area of three types of field margins (reed strips, grass strips and hedgerows) within a 500 meter buffer around the centroid of each crop fields had an effect on the abundance of bird species from three groups defined based on their primary habitat (reedbeds, grasslands, and forest edge species). We controlled for the area of each type of semi-natural habitat (wetlands, grasslands, and woodlands), crop diversity (rice, wheat, alfalfa, rape, and market gardening) and mean crop field size. Results show partial support of the compensation hypothesis with species-dependent responses to primary and substitute habitat area. Some species within the reedbed and grassland bird guilds are favored by the area of their primary habitat as well as by the area of field margins, in line with the compensation hypothesis. Eurasian reed warbler is favored by the area of both wetlands and reed strips. Corn bunting is favored by grassland and grass strip areas. We could not confirm the compensation hypothesis for other species. However, this may be due to the fact that most of these species did not respond to their primary habitat. These results therefore suggest that field margins may represent substitute habitats for some species but further studies, in contexts where species are strongly associated with their primary habitat, would be needed to confirm the generality of this hypothesis. Our results also suggest that species response to increasing the area of a field margin type may vary among guilds and even within guilds. Therefore, it may be difficult to favor all species within a given landscape and management actions may need to be tailored to whichever species are locally associated with the highest conservation priority. To tackle this challenge, it may be necessary to design landscape management actions at different spatial scales.

Copyright of Ibis is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Fasciolosis is a worldwide spread parasitosis mainly caused by the trematode Fasciola hepatica. This disease is particularly important for public health in tropical regions, but it can also affect the economies of many developed countries due to large infections in domestic animals. Although several studies have tried to understand the transmission by studying the prevalence of different host species, only a few have used population genetic approaches to understand the links between domestic and wildlife infections. Here, we present the results of such genetic approach combined with classical parasitological data (prevalence and intensity) by studying domestic and wild definitive hosts from Camargue (southern France) where fasciolosis is considered as a problem. We found 60% of domestic hosts (cattle) infected with F. hepatica but lower values in wild hosts (nutria, 19%; wild boars, 4.5%). We explored nine variable microsatellite loci for 1,148 adult flukes recovered from four different populations (non‐treated cattle, treated cattle, nutria and wild boars). Populations from the four groups differed, though we found a number of migrants particularly non‐treated cattle and nutria. Overall, we detected 729 different multilocus genotypes (from 783 completely genotyped individuals) and only 46 genotypes repeated across samples. Finally, we experimentally infected native and introduced intermediate snail hosts to explore their compatibility with F. hepatica and assess the risks of fasciolosis expansion in the region. The introduced species Galba truncatula and Pseudosuccinea columella attained the higher values of overall compatibility in relation to the European species. However, concerning the origin, sympatric combinations of G. truncatula were more compatible (higher prevalence, intensity and survival) than the allopatric tested. According to our results, we should note that the assessment of epidemiological risks cannot be limited to a single host–parasite system, but should focus on understanding the diversity of hosts in the heterogeneous environment through space and time. [ABSTRACT FROM AUTHOR]

Metallic trace elements (MTEs) constitute a major source of chemical pollution and represent a threat to aquatic ecosystems and organisms. Important variation in contamination may exist at a local scale in relation to the environment (hydrosystem, trophic ressources) and individual traits (age, sex). Heretofore, the factors influencing MTEs exposure of freshwater reptiles in temperate regions are not fully understood. Freshwater turtles have a relatively high trophic position and a long lifespan, thus being potentially highly exposed due to bioaccumulation and bioamplification processes. We investigated MTE blood concentrations from two populations of the European pond turtle (Emys orbicularis) in the Camargue wetland (France). These populations, monitored since 1997, differ in their habitat and exposure (irrigation versus drainage canal). In this study, we detected 7 MTEs (Cu, Fe, Hg, Mn, Pb, Se, and Zn) which levels depended on site and individual characteristics. Hg was positively related to body size and age, indicating an increase of exposure in older individuals. We found differences between males and females with the interaction with body size for Pb and Se and with age for Pb. Nitrogen and carbon stable isotopes varied only marginally between individuals and were poorly associated with MTEs concentrations, showing that trophic position might not explain MTEs contamination for these populations. At the individual level, Hg, Pb, and Se blood values were repeatable over years. Further studies should concentrate on potential ecophysiological effects to such exposure, especially since we recently evidenced that these populations of E. orbicularis are highly exposed to organic contaminants, which can lead to synergistic effects., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Marion Vittecoq reports financial support was provided by the Water Agency Rhône Méditérranée Corse. Olivier Lourdais reports financial support was provided by the French Biodiversity Office. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)