Parasitized or non-parasitized, why? A study of factors influencing tick burden in roe deer neonates.

Ixodes ricinus , the most common species of tick in Europe, is known to transmit major pathogens to animals and humans such as Babesia spp. or Borrelia spp.. Its abundance and distribution have been steadily increasing in Europe during recent decades, due to global environmental changes. Indeed, as ticks spend most of their life in the environment, their activity and life cycle are highly dependent on environmental conditions, and therefore on climate or habitat changes. Simultaneously, wild ungulates have expanded their range and increased dramatically in abundance worldwide, in particular roe deer ( Capreolus capreolus ), have allowed tick populations to grow and spread. Currently, tick infestation on newborn wild ungulates is poorly documented. However, newborn ungulates are considered more sensitive to tick bites and pathogen transmission because of their immature immune system. Thus, improving knowledge about the factors influencing tick infestation on newborns is essential to better understand their health risks. This study was conducted at Trois-Fontaines forest, Champagne-Ardenne, France (1992-2018). Based on a long-term monitoring of roe deer fawns, we used a novel Bayesian model of the infestation of fawns to identify which biotic or abiotic factors are likely to modify the level of infestation by ticks of 965 fawns over time. We show that tick burden increased faster during the first days of life of the fawns and became constant when fawns were 5 days old and more, which could be explained by the depletion of questing ticks or the turnover of ticks feeding on fawns. Moreover, the humidity, which favors tick activity, was weakly positively related to the tick burden. Our results demonstrate that tick infestation was highly variable among years, particularly between 2000 and 2009. We hypothesize that this results from a modification of habitat caused by hurricane Lothar.

Which Large- and Medium-Sized Mammals Use Commercial Short-Rotation Coppice as Habitat?

We surveyed occurrence and activity of large- and medium-sized mammals on six commercial mini-rotation short-rotation coppice (SRC) plantations in northern Germany by camera trapping in different seasons (winter, late summer). In total, eleven species (6–9 per site) were detected. This corresponds to the majority of mammal species occurring in the study region. Roe deer, wild boar and red fox were found across all sites. All other species were detected on fewer sites and some in only one of the seasons. Roe deer was the most active species both in terms of visit frequency (days with detection) and use intensity (detection numbers). With few exceptions on individual sites, all other species showed significantly lower activity. Number of detected species and activity of most of the species did not differ between seasons. Furthermore, there were no differences between near-edge and central areas of the crops with regard to the activity of the occurring species. Activity of individual species on different sites, however, differed considerably in some cases. Our results show that a wide range of mammal species are basically able to include SRC into their habitat utilisation. However, the sporadic use by most species indicates a rather limited current habitat value of the surveyed plantations. Options to increase the habitat value of SRC for mammals are suggested, but their effectiveness needs to be tested in future studies. Since the spatial and temporal scope of our study was limited and only SRC of a uniform age-class were considered, our results are not immediately applicable to other landscapes, seasons or types and management phases of SRC. Therefore, further research is required that considers these aspects as well as species-specific patterns of habitat selection in comparison to other habitat types.

Ancient Mitogenomes Suggest Stable Mitochondrial Clades of the Siberian Roe Deer

The roe deer (Capreolus spp.) has been present in China since the early Pleistocene. Despite abundant fossils available for detailed morphological analyses, little is known about the phylogenetic relationships of the fossil individuals to contemporary roe deer. We generated near-complete mitochondrial genomes for four roe deer remains from Northeastern China to explore the genetic connection of the ancient roe deer to the extant populations and to investigate the evolutionary history and population dynamics of this species. Phylogenetic analyses indicated the four ancient samples fall into three out of four different haplogroups of the Siberian roe deer. Haplogroup C, distributed throughout Eurasia, have existed in Northeastern China since at least the Late Pleistocene, while haplogroup A and D, found in the east of Lake Baikal, emerged in Northeastern China after the Mid Holocene. The Bayesian estimation suggested that the first split within the Siberian roe deer occurred approximately 0.34 million years ago (Ma). Moreover, Bayesian skyline plot analyses suggested that the Siberian roe deer had a population increase between 325 and 225 thousand years ago (Kya) and suffered a transient decline between 50 and 18 Kya. This study provides novel insights into the evolutionary history and population dynamics of the roe deer.

Roe deer population trend after reintroduction of Eurasian lynx within the Palatinate Forest: a first insight into a long-term study

After becoming extinct approximately 250 years ago in the Palatinate Forest, the first Eurasian lynx (Lynx lynx) were reintroduced within this area in 2016, with 20 lynx reintroduced in the following five years. We observed the roe deer population within the Palatinate Forest before (2016) and during (2017–2019) the lynx reintroduction by estimating the population and evaluating the hunting bag. The roe deer population estimation based on the distance sampling method was conducted on ten defined transects with an average length of 48 km from 2016 to 2019, observing a 6,000 km transect length for 120 nights overall. An average of 6.54 ± 1.28 roe deer km-² was estimated over the course of the four years (2016 – 2019). Since we suspect that our estimations might underestimate the roe deer population within the Palatinate Forest, hence we preferred to use the roe deer count index for further analysis. Over the first four years (2016–2019), significant differences were neither found in the roe deer count index nor for the hunting bag in relation to the reintroduction of the lynx. The data and findings presented in this study provide a first insight into a long-term observation of a predator-prey system within the Palatinate Forest, with roe deer not having experienced a natural predator over a long time. In order to make coherent interpretations, long-term data is needed to estimate the population trends of both species within the Palatinate Forest.

Effects of free-flight activities on wildlife: a poorly understood issue in conservation

Summary Recreational activities may have negative effects on wildlife, but there are very few studies specifically on the effects of free-flight activities (i.e., hang-gliders, paragliders and their powered derivatives) on wildlife. We review the existing scientific studies on this issue in order to identify the gaps in knowledge at the taxonomic-group level in order to develop guidelines to minimize the impacts of recreational free-flight on wildlife. We found that studies mainly concerned the effects on four ungulate species (chamois, red deer, roe deer and Alpine ibex) and, to a lesser extent, on raptors such as the golden eagle and two vulture species (bearded vulture and cinereous vulture). The studies have generally been carried out in high mountain areas (e.g., the European Alps). Data show that free-flight activities create disturbances and have negative effects on wildlife, resulting in increased energy expenditure, reduction of feeding time, abandonment of feeding areas, reduced breeding output, loss of body condition, increased predation risk and harm from flight accidents. However, the lack of studies on many species and areas, along with the small number of long-term studies, prevents proper assessment of the current situation regarding the impact of this activity on wildlife. We provide recommendations to improve the regulation of this activity.

Mapping and characterizing animals’ places of interest in forest environment

Fauna impacts its environment as well as spatial environment influences fauna space use. Forest management implies taking into account pressure from animals in fragile-balanced patches. Our goal is to propose maps that would benefit forest planning by reflecting individual movement and space use depending on the animal species and local spatiotemporal environment. The study case focuses on two species, roe deer and red deer, and on a forested site in the northeast of France. Movements of several individuals were analysed from collected GPS locations. Foraging places likely to correspond to intense research behaviour were computed using the First-Passage Time method. These places were assumed as being of interest and were characterized with landscape features and temporal information. Maps were produced to synthetize information about foraging places by defining adapted symbolizations. Then maps about functional space were proposed based on extrapolation of favourable or avoided areas from the characterized observed foraging places and space use. Landscape patches were mapped according to a gradient of potential interest by animals’ species, in order to highlight needs of specific planning actions in the forestry context. Map displays were driven by forestry end-use and designed so that to be compliant to a numeric geographical portal, giving access to different available on-line layers and computed created ones.

Metabarcoding in two isolated populations of wild roe deer (Capreolus capreolus) reveals variation in gastrointestinal nematode community composition between regions and among age classes

Background Gastrointestinal nematodes are ubiquitous for both domestic and wild ungulates and have varying consequences for health and fitness. They exist as complex communities of multiple co-infecting species, and we have a limited understanding of how these communities vary in different hosts, regions and circumstances or of how this affects their impacts. Methods We have undertaken ITS2 rDNA nemabiome metabarcoding with next-generation sequencing on populations of nematode larvae isolated from 149 fecal samples of roe deer of different sex and age classes in the two isolated populations of Chizé and Trois Fontaines in France not co-grazing with any domestic ungulate species. Results We identified 100 amplified sequence variants (ASVs) that were assigned to 14 gastrointestinal nematode taxa overall at either genus (29%) or species (71%) level. These taxa were dominated by parasites classically found in cervids—e.g. Ostertagia leptospicularis, Spiculopteragia spp. Higher parasite species diversity was present in the Trois Fontaines population than in the Chizé population including the presence of species more typically seen in domestic livestock (Haemonchus contortus, Bunostomum sp., Cooperia punctata, Teladorsagia circumcincta). No differences in parasite species diversity or community composition were seen in the samples collected from three zones of differing habitat quality within the Chizé study area. Young roe deer hosted the highest diversity of gastrointestinal nematodes, with more pronounced effects of age apparent in Trois Fontaines. The effect of host age differed between gastrointestinal nematode species, e.g. there was little effect on O. leptospicularis but a large effect on Trichostrongylus spp. No effect of host sex was detected in either site. Conclusions The presence of some livestock parasite species in the Trois Fontaines roe deer population was unexpected given the isolation of this population away from grazing domestic livestock since decades. Overall, our results illustrate the influence of host traits and the local environment on roe deer nemabiome and demonstrate the power of the nemabiome metabarcoding approach to elucidate the composition of gastrointestinal nematode communities in wildlife. Graphical Abstract