Swarming behaviour, catchment area and seasonal movement patterns of the Bechstein's bats : implications for conservation

Bats display marked seasonality throughout the temperate zone and use different habitats during different parts of the year. Unfortunately, detailed information regarding seasonal distribution and movements is often lacking, thereby hampering the development of adequate conservation measures. In this study we used radio telemetry to track females of the endangered Bechstein’s bat (Myotis bechsteinii) from autumn swarming sites to their summer maternity colony ranges. We were able to tag 22 individuals, 18 of which were subsequently recovered at nine roost sites up to 20.6 km away. Females from multiple colonies visited the same swarming site on a single night. Concurrently, we recovered females from a single maternity colony at different swarming sites on the same night. The catchment area of the investigated swarming sites measured 27.1 km2, and was skewed to the northwest. Tagged bats were recovered in forest fragments ranging in size from 5.42 to 128.98 ha. Notably, all but one of the recovered roosts were found in forests that have been continuously wooded since at least 1775. Surveys during the summer at these sites confirmed the presence of maternity colonies at six out of seven locations that could be investigated. Our study contributes to our understanding of swarming behavior and seasonal movement patterns, and exemplifies how these can be used to complete the year-round habitat use of bat species

Maltese bats show phylogeographic affiliation with North-Africa : implications for conservation

In the Mediterranean region, cryptic diversity of bats is common. As distinct genetic lineages should be managed independently for conservation, insight into bat phylogeography is important. The Maltese islands are located in the centre of the Mediterranean between North Africa and Sicily and are densely populated. At present, it is thought that at least seven species of bats are native, but phylogeographic affiliations remain largely unexplored. Therefore, we sequenced a ca. 540 bp fragment of the mitochondrial 16S rRNA gene from 23 bats, which were captured during the citizen-science project Akustika. We found two morphologically cryptic lineages common in North Africa, Plecotus gaisleri and a mainly North-African lineage of Hypsugo savii (named Hypsugo cf. darwinii in some recent studies). We also recorded two Pipistrellus species. The P. kuhlii haplotype belonged to a lineage present in North-Africa and across the Mediterranean. Within P. pipistrellus we found two novel haplotypes that clustered within a North-African clade, well distinguished from the European haplotypes. Our results highlight the historic connection between the bat fauna of the Maltese Islands and North Africa. Malta is one of the few regions in the European Union where P. gaisleri and the North-African clades of P. pipistrellus and H. savii occur. Hence, Malta has an exceptionally high responsibility for the conservation of these taxa in Europe

First molecular evidence of an invasive agricultural pest, Drosophila suzukii, in the diet of a common bat, Pipistrellus pipistrellus, in Belgian orchards

Bats are major consumers of arthropods, including many agricultural pest species, and can thus reduce and prevent crop damage. However, few, if any, data is available on the potential role of bats in pest control in central Europe. Evidence that bats prey upon locally important pest species would be an important first step to demonstrate their value to local farmers and facilitate conservation measures. In this pilot study, we used a DNA metabarcoding approach to investigate the diet composition of common pipistrelles and brown long-eared bats captured in orchards in Belgium. We show that the spotted wing drosophila (Drosophila suzukii), one of the most harmful pest species in this region, was part of the diet of common pipistrelles. This pest species was recorded in one of the five samples from common pipistrelles. Our results indicate that bats can be valuable assets for biological pest suppression in West-European orchards, thus setting a path for future studies

Mitigating the impact of microbial pressure on great (Parus major) and blue (Cyanistes caeruleus) tit hatching success through maternal immune investment

he hatching success of a bird’s egg is one of the key determinants of avian reproductive success, which may be compromised by microbial infections causing embryonic death. During incubation, outer eggshell bacterial communities pose a constant threat of pathogen translocation and embryo infection. One of the parental strategies to mitigate this threat is the incorporation of maternal immune factors into the egg albumen and yolk. It has been suggested that habitat changes like forest fragmentation can affect environmental factors and life-history traits that are linked to egg contamination. This study aims at investigating relationships between microbial pressure, immune investment and hatching success in two abundant forest bird species and analyzing to what extent these are driven by extrinsic (environmental) factors. We here compared (1) the bacterial load and composition on eggshells, (2) the level of immune defenses in eggs, and (3) the reproductive success between great (Parus major) and blue (Cyanistes caeruleus) tits in Belgium and examined if forest fragmentation affects these parameters. Analysis of 70 great tit and 34 blue tit eggshells revealed a similar microbiota composition (Enterobacteriaceae, Lactobacillus spp., Firmicutes and Bacteroidetes), but higher bacterial loads in great tits. Forest fragmentation was not identified as an important explanatory variable. Although a significant negative correlation between hatching success and bacterial load on the eggshells in great tits corroborates microbial pressure to be a driver of embryonic mortality, the overall hatching success was only marginally lower than in blue tits. This may be explained by the significantly higher levels of lysozyme and IgY in the eggs of great tits, protecting the embryo from increased infection pressure. Our results show that immune investment in eggs is suggested to be a species-specific adaptive trait that serves to protect hatchlings from pathogen pressure, which is not directly linked to habitat fragmentation

Season as a discriminating factor for faecal metabolomic composition of great tits (Parus major)

The microbiome of wild birds has been associated with health status and risk of disease development, but underlying metabolomic mechanisms are still unknown. Metabolites produced by microbial organisms may affect host metabolic processes and by doing so influence host health. Here we provide for the first time data on the faecal metabolome of wild great tits (Parus major) by analyzing metabolites associations with age, sex, season and body condition. Using untargeted metabolomics, we analyzed faecal samples from 112 great tits that were caught in a deciduous forest fragment in Flanders (Belgium) during late autumn and 19 animals that were re-captured during early spring. In this study, no significant associations between the faecal metabolites and age, sex and body condition were observed. However, season was shown to be a discriminating factor for the metabolomic composition of great tits, suggesting an impact of environmental factors

Host phylogeny, geographic overlap, and roost sharing shape parasite communities in European bats

How multitrophic relationships between wildlife communities and their ectoparasitic vectors interact to shape the diversity of vector-borne microorganisms is poorly understood. Nested levels of dependence among microbes, vectors, and vertebrate hosts may have complicated effects on both microbial community assembly and evolution. We examined Bartonella sequences from European bats and their ectoparasites with a combination of network analysis, Bayesian phylogenetics, tip-association and cophylogeny tests, and linear regression to understand the ecological and evolutionary processes that shape parasite communities. We detected seven batectoparasite-Bartonella communities that can be differentiated based on bat families and roosting patterns. Tips of the Bartonella tree were significantly clustered by host taxonomy and geography. We also found significant evidence of evolutionary congruence between bat host and Bartonella phylogenies, indicating that bacterial species have evolved to infect related bat species. Exploring these ecological and evolutionary associations further, we found that sharing of Bartonella species among bat hosts was strongly associated with host phylogenetic distance and roost sharing and less strongly with geographic range overlap. Ectoparasite sharing between hosts was strongly predicted by host phylogenetic distance, roost sharing, and geographic overlap but had no additive effect on Bartonella sharing. Finally, historical Bartonella host-switching was more frequent for closely related bats after accounting for sampling bias among bat species. This study helps to disentangle the complex ecology and evolution of Bartonella bacteria in bat species and their arthropod vectors. Our work provides insight into the important mechanisms that partition parasite communities among hosts, particularly the effect of host phylogeny and roost sharing, and could help to elucidate the evolutionary patterns of other diverse vector-borne microorganisms

Salmonella Typhimurium DT193 and DT99 are present in great and blue tits in Flanders, Belgium

Endemic infections with the common avian pathogen Salmonella enterica subspecies enterica serovar Typhimurium (Salmonella Typhimurium) may incur a significant cost on the host population. In this study, we determined the potential of endemic Salmonella infections to reduce the reproductive success of blue (Cyanistes caeruleus) and great (Parus major) tits by correlating eggshell infection with reproductive parameters. The fifth egg of each clutch was collected from nest boxes in 19 deciduous forest fragments. Out of the 101 sampled eggs, 7 Salmonella Typhimurium isolates were recovered. The low bacterial prevalence was reflected by a similarly low serological prevalence in the fledglings. In this study with a relatively small sample size, presence of Salmonella did not affect reproductive parameters (egg volume, clutch size, number of nestlings and number of fledglings), nor the health status of the fledglings. However, in order to clarify the impact on health and reproduction a larger number of samples have to be analyzed. Phage typing showed that the isolates belonged to the definitive phage types (DT) 193 and 99, and multi-locus variable number tandem repeat analysis (MLVA) demonstrated a high similarity among the tit isolates, but distinction to human isolates. These findings suggest the presence of passerine-adapted Salmonella strains in free-ranging tit populations with host pathogen co-existence

Waarnemingen.be : non-native plant and animal occurrences in Flanders and the Brussels Capital Region, Belgium

Citizen scientists make important contributions to the collection of occurrence data of non-native species. We present two datasets comprising more than 520,000 records of 1,771 non-native species from Flanders and the Brussels Capital Region in Belgium, Western Europe, collected through the website http://www.waamemingen.be hosted by Stichting Natuurinformatie and managed by the nature conservation NGO Natuurpunt. Most records were collected by citizen scientists, mainly since 2008. Waarnemingen.be aims at recording all species, native and non-native, and it is shown here that this kind of biodiversity portals are also particularly well suited to collect large amounts of data on non-native species. Both datasets presented here are also discoverable through the Global Biodiversity Information Facility (GBIF)