Habitat selection by the European hare in arable landscapes: The importance of small-scale habitat structure for conservation

Living in human-modified landscapes narrows the dietary niche of a specialised mammalian scavenger

Anthropogenic impacts on carnivores can be complex, posing numerous threats to many species, yet also benefits to those able to exploit certain resources. This balancing act is particularly precarious for those adapters that exploit dietary resources provided by humans, but still require other resources only available in native habitat. Here we measure the dietary niche of one such species, the Tasmanian devil (Sarcophilus harrisii), a specialised mammalian scavenger, across an anthropogenic habitat gradient stretching from cleared pasture to undisturbed rainforest. Populations inhabiting areas of greater disturbance showed restricted dietary niches, suggesting that all individuals fed on similar food items, even within regenerated native forest. Populations in undisturbed rainforest habitats had comparatively broad diets and showed evidence of niche partitioning by body size, which may reduce intraspecific competition. Despite the potential benefits of reliable access to high-quality food items in anthropogenically-modified habitats, the constrained niches we observed may be harmful, indicating altered behaviours and potentially increasing the rate of fights between individuals over food. This is of particular concern for a species at risk of extinction due to a deadly cancer primarily transmitted through aggressive interactions. The lack of diversity in devil diets within regenerated native forest compared to those in old-growth rainforest also indicates the conservation value of the latter for both the devil and the species which they consume.

Co-occurrence patterns and habitat selection of the mountain hare, European hare, and European rabbit in urban areas of Sweden

Assessing the underlying mechanisms of species co-occurrence patterns can be challenging as biotic and abiotic factors are hard to disentangle. To date, few studies have investigated co-occurrence patterns of mammals within urban areas. As urban areas are increasingly used as habitat by wildlife, there is a need for a better understanding of urban ecology to facilitate human-wildlife co-existence. Here, we investigated co-occurrence patterns and habitat selection of the European hare (Lepus europaeus), mountain hare (L. timidus), and European rabbit (Oryctolagus cuniculus) inside urban areas of Sweden, using joint species distribution models and generalized linear mixed models based on citizen science observations. All three species were observed within urban areas, but European hares and rabbits appear to be more successful urban colonizers compared to mountain hares. Overall, our findings suggested that urban occurrence by all three lagomorphs was related to suitable conditions within the distribution of each species (e.g., climate and elevation), rather than by the presence of other lagomorph species or specific land cover types within urban areas. On a finer spatial scale, European hares and rabbits generally selected for green urban areas and mountain hares for residential gardens, which likely constitute suitable foraging sites. Moreover, overlap in activity times between European hares and rabbits was mediated by land cover type and sympatry. Our findings contribute to the understanding of urban ecology and provide insights for management measures of the three lagomorphs in urban areas of Sweden.

Maize monoculture causes niacin deficiency in free-living European brown hares and impairs local population development

Maize (Zea mays) is the most produced crop worldwide and the second most important bio-energy plant. Huge maize monoculture is considered a threat to biodiversity in agricultural landscapes and may also contribute to the decline of European brown hares (Lepus europaeus, Pallas 1778). Indeed, the intensification of agriculture has been identified as one of the main factors responsible for the decline of brown hare populations. A reason why large maize cultures can be particularly detrimental to animals consuming this plant is its poor nutritional value with respect to niacin. In this study, we investigated the effects of the proportion of area under maize crops on liver concentrations of niacin in free-living hares, on the reproductive output of does (females), and on the development of local populations, at nine study sites in Lower Austria. Hare numbers were estimated from spotlight counts in spring and autumn. Liver samples and uteri were obtained from hares shot in the same areas during regular autumn hunts. Number of offspring born to an individual female during the preceding reproductive period was determined by counting placental scars. Our results show a significant negative effect of the area under maize crops on liver concentrations of niacin of does and on their reproductive output. Further, we found a significant negative effect of the area under maize on the development of a population. Altogether, our findings indicate that high proportions of the area under maize crops contribute to the decline of brown hares by reduced fecundity of does and impaired development of local populations.

Driving Mechanism of Habitat Quality at Different Grid-Scales in a Metropolitan City

Urban ecosystem dysfunction, habitat fragmentation, and biodiversity loss caused by rapid urbanization have threatened sustainable urban development. Urban habitat quality is one of the important indicators for assessing the urban ecological environment. Therefore, it is of great practical significance to carry out a study on the driving mechanism of urban habitat quality and integrate the results into urban planning. In this study, taking Zhengzhou, China, as an example, the InVEST model was used to analyze the spatial differentiation characteristics of urban habitat quality and Geodetector software was adopted to explore the driving mechanism of habitat quality at different grid-scales. The results show the following: (1) LUCC, altitude, slope, surface roughness, relief amplitude, population, nighttime light, and NDVI are the dominant factors affecting the spatial differentiation of habitat quality. Among them, the impacts of slope, surface roughness, population, nighttime light, and NDVI on habitat quality are highly sensitive to varying grid-scales. At the grid-scale of 1000 to 1250 m, the impacts of the dominant factors on habitat quality is closer to the mean level of multiple scales. (2) The impact of each factor on the spatial distribution of habitat quality is different, and the difference between most factors has always been significant regardless of the variation of grid-scales. The superimposed impact of two factors on the spatial distribution of habitat quality is greater than the impact of the single factor. (3) Combined with the research results and the local conditions of Zhengzhou, we put forward some directions of habitat protection around adjusting urban land use structure, applying nature-based solutions and establishing a systematic thinking model for multi-level urban habitat sustainability.

Seed traits matter-Endozoochoric dispersal through a pervasive mobile linker

Although many plants are dispersed by wind and seeds can travel long distances across unsuitable matrix areas, a large proportion relies on co-evolved zoochorous seed dispersal to connect populations in isolated habitat islands. Particularly in agricultural landscapes, where remaining habitat patches are often very small and highly isolated, mobile linkers as zoochorous seed dispersers are critical for the population dynamics of numerous plant species. However, knowledge about the quali- or quantification of such mobile link processes, especially in agricultural landscapes, is still limited. In a controlled feeding experiment, we recorded the seed intake and germination success after complete digestion by the European brown hare (Lepus europaeus) and explored its mobile link potential as an endozoochoric seed disperser. Utilizing a suite of common, rare, and potentially invasive plant species, we disentangled the effects of seed morphological traits on germination success while controlling for phylogenetic relatedness. Further, we measured the landscape connectivity via hares in two contrasting agricultural landscapes (simple: few natural and semi-natural structures, large fields; complex: high amount of natural and semi-natural structures, small fields) using GPS-based movement data. With 34,710 seeds of 44 plant species fed, one of 200 seeds (0.51%) with seedlings of 33 species germinated from feces. Germination after complete digestion was positively related to denser seeds with comparatively small surface area and a relatively slender and elongated shape, suggesting that, for hares, the most critical seed characteristics for successful endozoochorous seed dispersal minimize exposure of the seed to the stomach and the associated digestive system. Furthermore, we could show that a hare's retention time is long enough to interconnect different habitats, especially grasslands and fields. Thus, besides other seed dispersal mechanisms, this most likely allows hares to act as effective mobile linkers contributing to ecosystem stability in times of agricultural intensification, not only in complex but also in simple landscapes.

Agri-environment schemes do not support Brown Hare populations due to inadequate scheme application

The goal of many agri-environment schemes (AES) is to increase biodiversity in agroecosystems. AES effects are often measured on invertebrates and birds; mammals as indicator species are infrequently targets of such researches. Our goal was to evaluate the local-scale effects of the Hungarian Agri-Environmental Measures (AEM) on the European brown hare (Lepus europaeus), which shows decreasing population trends across Europe. We compared hare abundances and their dropping numbers in AEM and control agricultural arable and grassland fields of 17 game management units in two seasons. We also examined the quality of arable fields based on their margin width and vegetation cover. We found that margin quality was higher in AEM than in the control fields. Control grasslands had higher vegetation quality than the AEM grasslands. We found a significant difference in hare counts between AEM and control arable fields in spring but no difference in autumn. The dropping densities did not differ in any season, treatment category or agroecosystem type. We conclude that the AEM program (2009-2014) in Hungary was not effective for the hare, and this might have been caused by the inadequate or weak application of AEM practices. We provide recommendations for future AEM programs to enhance biodiversity.

Spatiotemporal Overlap between the European Brown Hare and Its Potential Predators and Competitors

Analysis of spatiotemporal partitioning is pivotal to shed light on interspecific coexistence. Most research effort has involved large-sized carnivores and their prey, whereas little attention has been devoted to lagomorphs. We assessed spatiotemporal overlap among the European brown hare Lepus europaeus and its potential competitors and predators through camera-trapping in an area in Central Italy. We estimated the interspecific patterns of the spatiotemporal activity rhythms of brown hares, its potential predators (the red fox Vulpes vulpes, the pine marten Martes martes, the domestic cat Felis catus, and the domestic dog Canis familiaris), and a competitor, the roe deer Capreolus capreolus. Brown hare activity was studied in natural conditions as well as in a fenced area that excluded terrestrial predators and competitors. Free-ranging hares developed a more nocturnal behavior to avoid diurnal predators (i.e., domestic carnivores and martens). Although high temporal overlap was observed between free-ranging brown hares and both red foxes (82%) and roe deer (81%), hares avoided fox by being more active on darkest nights, as well as avoided roe deer through spatial partitioning. We suggest that hares may adapt their spatiotemporal behavior to avoid potential predators and competitors.

Burrowing and Anti-Predator Requirements Determine the Microhabitat Selection of Himalayan Marmot in Zoige Wetland

To satisfy their requirements for food and safety, animals need certain habitats to live. Marmots generally select habitats with certain elevation, land surface temperature, soil and vegetation type, and certain mountain slope and aspect; however, what habitats are needed at relatively smaller scales are poorly known. The Himalayan marmot (Marmota himalayana) is distributed mainly on the Qinghai-Tibet Plateau, a region exhibiting diversified topographic features, and the Zoige wetland in the northeast part of the plateau is also the home of the Himalayan marmot. The region is famous for its plateau peat bog, and the suitable habitats for Himalayan marmots are patchily distributed in the wetland. To investigate what kinds of patches are preferred by the marmot in this wetland ecosystem, we measured and compared the soil and vegetation characteristics of used and unused patches. We found that unlike factors governing the habitat selection at macroscales, patches characterized by flat ground and low soil moisture content, with medium vegetation standing height and low vegetation density, are selected in the Zoige wetland. Patches of this kind are selected to meet the marmots' requirements for burrow construction and predator avoidance in such a wetland ecosystem. Together with previous studies on habitat selection of the marmot species at macroscales, we showed that to explore how the animals survive in an environment, it is important to conduct the analysis at multiple scales.

Influence of cereal harvest on adrenocortical activity in European hares (Lepus europaeus)

Anthropogenic disturbances, such as habitat modifications and machines, are associated with increased levels of faecal glucocorticoid metabolites (fGCMs) in mammals, an indicator of a stress response. One human-caused process provoking incisive habitat alterations is harvesting arable crops. We investigated the effect of cereal harvest on fGCM concentrations in European hares (Lepus europaeus) in arable landscapes in lower Austria during the year 2018 by collecting 591 faecal samples before, during and after cereal harvest. fGCMs were analysed using an enzyme immunoassay, and data were analysed using linear mixed-effects models. We found that neither cereal harvest nor farming practice (organic vs. conventional) caused an overall increase in the hares’ stress level. Lower vegetation density and higher proportions of bare ground were negatively correlated with fGCM concentrations, whereas the proportion of stubble fields was significantly positively correlated with fGCM concentrations in European hares. A change to more open landscapes might decrease time spent avoiding predation, and fallen grains may provide a beneficial additional food source for the hares. This indicates that European hares are well adapted to an opening up of the landscape and short-term disturbances such as cereal harvesting. In conclusion, cereal harvest had no large impact on European hares’ adrenocortical activity in an arable landscape with small average field size and enough available non-farmed areas.

European hares do not avoid newly pesticide-sprayed fields: Overspray as unnoticed pathway of pesticide exposure

Although risk assessments for pesticides involve quantifying exposure routes for animals, little empirical evidence exists on how individuals use areas where pesticides were used. Further, the European Food Safety Authority guidelines for the risk assessment of birds and mammals currently only include direct dietary uptake from exposed plants as important pathway for pesticides, arguing that dermal exposure is generally negligible. Here, we use the European hare (Lepus europaeus) as a model of a farmland specialist to investigate if (1) hares adjust habitat use in response to pesticide spraying, using GPS data, and (2) calculate the pesticide exposure and uptake over different pathways, i.e. foraging uptake versus overspray and subsequent oral grooming, using an agent-based modelling approach. Apart from avoidance of sprayed fields on the spraying day by inactive hares, which was likely caused by the mechanical disturbance rather than the pesticide itself, we found no evidence that hares reduced the use of pesticide-sprayed fields compared to control observations where no pesticides were applied. Our simulation showed that both the proportion of exposed individuals and the pesticide uptake were related to the pathway of exposure (foraging versus overspray/oral grooming), and depended on the age class and the vegetation type. We found that pesticide uptake via overspray/oral grooming might be 7-fold higher compared to foraging and might thus be an important pathway of pesticide exposure in hares. Our findings emphasize that policy makers, specifically the European Food Safety Authority, should incorporate alternative pathways of pesticide exposure for birds and mammals, such as overspray and oral grooming, when conducting environmental risk assessments and take variation in vegetation structure and age-related animal behavior into account, because these factors might affect pesticide exposure. Interactions between pesticide application and vegetation structure may both increase or decrease exposure but can be predicted using a simulation approach.