Behaviour of horses and cattle at two stocking densities in a coastal salt marsh

Livestock grazing has been practiced in salt marshes in the Wadden Sea area since 600 B.C. Currently livestock grazing is also applied for conservation management. However, effects of such grazing management on salt marshes are likely to vary depending on the species of livestock and stocking density due to differences in the behaviour of the animals. Yet, little is known about the behaviour of different livestock species and stocking densities grazing in salt marshes. We studied the grazing behaviour of horses and cattle by focal observation in an experiment with four different grazing treatments on a coastal salt marsh. In all treatments we recorded diet choice, movement and grazing activity, and spatial distribution. Livestock species shared an overlap in diet choice. Yet, horses more often foraged on the short grass Puccinellia maritima, while the cattle diet contained a higher amount of Aster tripolium. Horses travelled longer distances per day and spent more time grazing than cattle. Spatial distribution of cattle was significantly clustered, while horses showed a random distribution utilizing the whole area. Animal behaviour differs between livestock species and stocking densities with respect to diet choice, activity and spatial distribution

Relationships of reproductive performance indicators in black rhinoceros (Diceros bicornis michaeli) with plant available moisture, plant available nutrients and woody cover

Plant available moisture and plant available nutrients in soils influence forage quality and availability and subsequently affect reproductive performance in herbivores. However, the relationship of soil moisture, soil nutrients and woody forage with reproductive performance indicators is not well understood in mega-browsers yet these three are important in selecting suitable areas for conservation of mega-browsers. Here, the eastern black rhinoceros (Diceros bicornis michaeli), a mega-browser, was studied in seven geographically distinct populations in Kenya to understand the relationships between its reproductive performance indicators and plant available moisture, plant available nutrients and woody cover. Reproductive parameters showed a complex relationship with plant available moisture and plant available nutrients. We found an increase in the predicted yearly percentage of females calving as plant available nutrients decreased in areas of high levels of plant available moisture but no relationship with plant available nutrients in areas of low plant available moisture. Age at first calving was earlier, inter-calving interval was longer and yearly percentage of females calving was higher at higher woody cover. Woody plant cover contributes positively to black rhino reproduction performance indicators, whereas plant available moisture and plant available nutrients add to the selection of conservation areas, in more subtle ways.</p

Data from: Does wolf presence reduce moose browsing intensity in young forest plantations?

Large carnivores can be a key factor in shaping their ungulate prey’s behavior, which may affect lower trophic levels. While most studies on trade-offs between food acquisition and risk avoidance by ungulate prey species have been conducted in areas with limited human impact, carnivores are now increasingly returning to highly anthropogenic landscapes. Many of these landscapes are dominated by forestry, and ungulate-forestry conflicts are an increasing issue. The aim of this study was to test if the indirect effects of a re-colonizing large predator, the wolf (Canis lupus), results in a change in browsing intensity by moose (Alces alces) in young forest plantations in a boreal forest in Sweden. We selected 24 different forest plantations, with 12 located in low-wolf and 12 in high-wolf utilization areas. In each plantation, we measured browsing intensity, tree height, tree density, distance to the closest forest edge and we counted the number of moose pellet groups. In contrast to our predictions, wolf utilization was not the main driver of moose browsing patterns. Instead, moose browsing intensity declined with tree density and height. Separate analyses on the main tree species showed that wolf utilization had an influence, but browsing intensity was in fact higher in the high-wolf utilization areas for three out of five tree species. This pattern seemed to be driven by a strong confounding relationship between wolf utilization, tree density and height, which were both lower in the high-wolf utilization areas. We argue that this confounding effect is due to wolves being pushed towards the less productive parts of the landscape away from human activity centers. Therefore, we concluded that in order to better understand carnivore driven risk- mediated effects on herbivore behavior in anthropogenic landscapes we need to better understand the complexity of human-carnivore-prey-ecosystem interactions

Cascading effects of predator activity on tick-borne disease risk.

Predators and competitors of vertebrates can in theory reduce the density of infected nymphs (DIN)-an often-used measure of tick-borne disease risk-by lowering the density of reservoir-competent hosts and/or the tick burden on reservoir-competent hosts. We investigated this possible indirect effect of predators by comparing data from 20 forest plots across the Netherlands that varied in predator abundance. In each plot, we measured the density of questing Ixodes ricinus nymphs (DON), DIN for three pathogens, rodent density, the tick burden on rodents and the activity of mammalian predators. We analysed whether rodent density and tick burden on rodents were correlated with predator activity, and how rodent density and tick burden predicted DON and DIN for the three pathogens. We found that larval burden on two rodent species decreased with activity of two predator species, while DON and DIN for all three pathogens increased with larval burden on rodents, as predicted. Path analyses supported an indirect negative correlation of activity of both predator species with DON and DIN. Our results suggest that predators can indeed lower the number of ticks feeding on reservoir-competent hosts, which implies that changes in predator abundance may have cascading effects on tick-borne disease risk

Reactive response to predation risk affects foraging time of hares, yet not their phosphorus intake

Antipredator responses could affect nutrient intake, which could lead to nutritional deficits. However, little is known about the antipredator response of small herbivores because most are nocturnal or crepuscular and therefore very difficult to study in the field. Therefore, we experimentally assessed the effect of a reactive response to predation risk on the nutrient (i.e., phosphorous) intake of the European hare (Lepus europaeus) using three different playback sounds. Additionally, we studied the time spent being costly vigilant, the time spent foraging, and the vegetation height in which the hares were present using accelerometers and GPS. Our results showed that elevated predation risk from our playback experiment did not affect the (1) phosphorus intake, (2) time spent being costly vigilant, and (3) time spent in tall vegetation. However, elevated predation risk did increase the time spent foraging. Possibly hares spent more time foraging with an increased predation risk because hares cannot seek refuge from predators. Additionally, the effect on phosphorus intake could be weak because phosphorous intake does not benefit a flight escape, while the reactive response acts late in the predation sequence limiting the effect on hare ecology. Prey anti-predator responses seem strongly related to the escape tactics of prey species that can differ between different habitats and the time of the day. More detailed field studies are necessary to get a better insight into species’ anti-predator-food tactics.</p

Spatial genetic structure of European wild boar, with inferences on late-Pleistocene and Holocene demographic history

European wildlife has been subjected to intensifying levels of anthropogenic impact throughout the Holocene, yet the main genetic partitioning of many species is thought to still reflect the late-Pleistocene glacial refugia. We analyzed 26,342 nuclear SNPs of 464 wild boar (Sus scrofa) across the European continent to infer demographic history and reassess the genetic consequences of natural and anthropogenic forces. We found that population fragmentation, inbreeding and recent hybridization with domestic pigs have caused the spatial genetic structure to be heterogeneous at the local scale. Underlying local anthropogenic signatures, we found a deep genetic structure in the form of an arch-shaped cline extending from the Dinaric Alps, via Southeastern Europe and the Baltic states, to Western Europe and, finally, to the genetically diverged Iberian peninsula. These findings indicate that, despite considerable anthropogenic influence, the deeper, natural continental structure is still intact. Regarding the glacial refugia, our findings show a weaker signal than generally assumed, but are nevertheless suggestive of two main recolonization routes, with important roles for Southern France and the Balkans. Our results highlight the importance of applying genomic resources and framing genetic results within a species’ demographic history and geographic distribution for a better understanding of the complex mixture of underlying processes

Cascading effects of predator activity on tick-borne disease risk: Dataset

All data used in the analyses of the manuscript entitled: Cascading effects of predator activity on tick-borne disease ris

Enoclerus (E.) topes (dorsal)

Vista dorsal del holotipo de Enoclerus (E.) topes Rifkin

Data from: Genome-wide single nucleotide polymorphism analysis reveals recent genetic introgression from domestic pigs into Northwest European wild boar populations

Present-day genetic introgression from domestic pigs into European wild boar has been suggested in various studies. However, no hybrids have been identified beyond doubt mainly because available methods were unable to quantify the extent of introgression and rule out natural processes. Genetic introgression from domestic pigs may have far-reaching ecological consequences by altering traits like the reproduction rate or immunology of wild boar. In this study, we demonstrate a novel approach to investigate genetic introgression in a Northwest (NW) European wild boar data set using a genome-wide single nucleotide polymorphism (SNP) assay developed for domestic pigs. We quantified the extent of introgression using allele frequency spectrum analysis, in silico hybridization simulations and genome distribution patterns of introgressed SNPs. Levels of recent introgression in the study area were expected to be low, as pig farming practices are prevailingly intensive and indoors. However, evidence was found for geographically widespread presence of domestic pig SNPs in 10% of analysed wild boar. This was supported by the identification of two different pig mitochondrial DNA haplotypes in three of the identified hybrid wild boar, suggesting that introgression had occurred from multiple sources (pig breeds). In silico hybridization simulations showed that the level of introgression in the identified hybrid wild boar is equivalent to first-generation hybrids until fifth-generation backcrosses with wild boar. The distribution pattern of introgressed SNPs supported these assignments in four of nine hybrids. The other five hybrids are considered advanced-generation hybrids, resulting from interbreeding among hybrid individuals. Three of nine hybrids were genetically associated with a different wild boar population than the one in which they were sampled. This discrepancy suggests that genetic introgression has occurred through the escape or release of an already hybridized farmed wild boar stock. We conclude that genetic introgression from domestic pigs into NW European wild boar populations is more recent and more common than expected and that genome-wide SNP analysis is a promising tool to quantify recent hybridization in free-living populations