European brown hare syndrome in free-ranging European brown and mountain hares from Switzerland.

From 1997 to 2000, complete necropsy and histopathologic investigations were performed on 157 free-ranging European brown hares (Lepus europaeus) found dead throughout Switzerland. Organ samples of all these individuals (157 livers and 107 spleens available) were tested for European brown hare syndrome virus (EBHSV)-antigen by enzyme-linked immunosorbent assay (ELISA) test kit. Furthermore, 60 additional blood samples were tested for antibodies against EBHSV by ELISA. In addition, liver samples of 87 free-ranging mountain hares (Lepus timidus) hunted in 1996 were tested for EBHSV-antigen. In two European brown hares from southern Switzerland lesions suggestive of changes induced by EBHSV were present, and high titers of EBHSV-antigen were detected in both liver and spleen samples of these animals. Based on negative staining electron microscopy investigations of liver and spleen homogenates, we observed calicivirus in one antigen-positive hare. Low EBHSV-antigen titers were found in three additional European brown hares from central and western Switzerland, but EBHS-lesions were absent. Antibodies against EBHSV were not detected in any of the sera of European brown hares, and EBHSV-antigen was not found in the samples of mountain hares. This is the first report of EBHS in European brown hares from Switzerland.     

Spatial behaviour of the Apennine hare: Are females territorial?

The spatial behaviour of seven male and five female Apennine hares Lepus corsicanus was studied in a scrub-wood area of Central Italy, through radiotracking. The median percentage of home-range overlap was about five times lower between females (< 15%) than between males (75%). Intrasexual aggression was recorded for females, but never for males. No species within the Lepus genus are known to be territorial, whereas we suggest that inter-individual female intolerance in the Apennine hare may be compatible with territoriality. The Apennine hare is also unusual among hares because it reproduces throughout the year, that is also during food-poor months, which could have triggered resource defence between females to maximise their reproductive fitness.     

Evidence of autumn reproduction in female European hares (Lepus europaeus) from southern Europe

Information on reproductive biology of the European hare (Lepus europaeus) in different environmental and landscape conditions comprises part of fundamental knowledge regarding species’ adaptive responses as well as many aspects of its biology. Most of the studies conducted on European hare reproduction are confined to midlatitude and northern populations, whereas no data exist on the indigenous southern populations. Here, we present information on reproductive characteristics of European hares inhabiting Mediterranean ecosystems on the island of Crete, Greece for two successive hunting seasons. Although the annual reproductive cycle of the species is well known, with an autumn sexual inactivity, the duration of this period is subjected to fluctuations in different years and for different areas. According to our data, hare populations of Crete present an autumn–early winter reproductive activity with high proportions of pregnant females observed in all the months of the study. Furthermore, the estimated mean litter size (1.54 SE ± 0.07) while signed to the lowest values ever observed for European hares is similar to values obtained in continuous breeding species of the same genus, Lepus granatensis, Lepus corsicanus, Lepus (capensis) mediterraneus, and Lepus capensis also inhabiting warm climates. In conclusion, our results suggest that Cretan European hare populations exhibit a reproductively active period during autumn–early winter where proportions of pregnant females and litter size give a strong indication of a continuous reproduction throughout the year.     

Predation Risk Drives Habitat‐Specific Sex Ratio in a Monomorphic Species,the Brown Hare (Lepus europaeus)

In dimorphic species, sexual habitat segregation is generally explained by the differences in nutritional needs or by a trade‐off between fulfilling food requirements and avoiding predation. However, it remains unclear whether predation risk is strong enough to drive the differences in habitat use between sexes as predicted by the predation sensitivity hypothesis. Here we test in a monomorphic species, the brown hare (Lepus europaeus), the prediction that abundance of the gender more sensitive to predation is higher in safer habitat. We used data on 1645 individually marked hares in western Poland during autumn–winter seasons of 1966/1967–1978/1979 to estimate sex‐specific annual survival rates. We analyzed the stomach contents of 134 foxes shot in 1965/1966–1994/1995 to evaluate fox predation on hares. Finally, we employed data on 26 790 hares live‐trapped in 1965/1966–1994/1995 to analyze hare sex ratio across habitats. We found that male annual survival rate was lower than that of females and that the predation risk by foxes on hares was lower in agricultural than forest habitat. Our finding, that males were more often trapped by nets in agricultural than the forest habitat, provides indirect evidence for the predation sensitivity hypothesis. We conclude that predation risk can be a driving force for habitat‐specific sex ratio in a monomorphic species such as the brown hare.     

Diet selection by hares (Lepus europaeus) in arable land and its implications for habitat management

Populations of European hares (Lepus europaeus) have experienced a dramatic decline throughout Europe in recent decades. European hares are assumed to prefer weeds over arable crops, and weed abundance was reduced by the intensification of agriculture. Therefore, modern agriculture has been blamed as a major factor affecting European hare populations. However, it is questionable whether European hares select weeds at all, as previous studies had major methodological limitations. By comparing availability and use of plants with Chesson’s Electivity Index, we investigated whether the European hare actually feeds selectively on different plants in arable land. Food availability and use were dominated by cultivated crops (e.g. winter wheat, spring barley and sugar beet). Diet selection analysis revealed that in autumn and winter, European hares predominantly preferred cultivated crops (winter wheat) and food items provided by hunters (tubers of sugar beet and carrot). In spring and summer, apart from soy, only weeds (e.g. clover and corn poppy) were positively selected, especially after cereal crops were harvested. We suggest that the decline in European hare populations throughout Europe was facilitated by the decrease in weed abundance. Wildlife-friendly set-asides in arable land have the potential to reconcile the European Union’s Common Agricultural Policy with wildlife conservation.     

Demographic differences in diet breadth of Canada lynx during a fluctuation in prey availability

Population dynamics of specialist carnivores are closely linked to prey availability, but the extent of variability in diet breadth of individual carnivores relative to natural variability in the abundance of their primary prey is not well understood. Canada lynx (Lynx canadensis) specialize on snowshoe hares (Lepus americanus) and exhibit cyclic fluctuations in abundance that lag 1–2 years behind those of snowshoe hares. Declining hare densities spur demographic changes in lynx, but it is unclear whether a corresponding increase in diet breadth occurs: (1) broadly across a lynx population; (2) only among individuals who are able to effectively switch to alternative prey; or (3) only among individuals who cannot capture sufficient primary prey. We measured stable isotope ratios of lynx muscle tissue spanning a cyclic increase and decline in hare density (1998–2001) in Fort Providence, NT, Canada. We found that lynx cohorts responded differently to hare population change, with yearling animals having broader diets at low hare densities, while adults and dependent juveniles maintained a constant diet through the initial decline in hare density. This result was consistent irrespective of lynx sex and indicates that yearling lynx likely are forced to adopt a broader diet when primary prey densities decline. Our results imply that select cohorts of specialist carnivores can exhibit high dietary plasticity in response to changes in primary prey abundance, prompting the need to determine whether increased diet breadth in young lynx is a successful strategy for surviving through periods of snowshoe hare scarcity. In this way, cohort‐specific niche expansion could strongly affect the dynamics of organisms exhibiting population cycles.     

The effect of establishing native woodland on habitat selection and ranging of moorland mountain hares (Lepus timidus), a flexible forager

Mountain hares Lepus timidus L. typify species that occupy a broad geographic range and have flexible foraging and nutritional strategies. Such species may show a range of responses to habitat modification. This study aimed to provide a basis for prediction of the impact of mountain hares on woodland establishment, and of woodland establishment on mountain hare distribution. The selection of and the extent of incorporation of new woodland into the home range of mountain hares was investigated in an area where Scots pine Pinus sylvestris L. woodland was establishing within their usual habitat in Britain, upland heather moorland. Seasonal home, day and night-range sizes of radio-tracked mountain hares were determined using the multinuclear probability polygon technique and analysed using residual maximum likelihood (REML). Habitat selection was analysed using compositional analysis. Three main habitat types were available to hares: heather moorland with trees, heather moorland and grassland-mire. Mean home-range size of mountain hares in summer was 10.3 ha and in winter 9.6 ha. There were no significant seasonal or sex differences in home-range size. Females selected grassland-mire habitat in summer and showed no strong selection for any habitat in winter. Males selected heather moorland in both summer and winter. Heather moorland with trees was not selected preferentially by mountain hares of either sex in summer or winter. The absence of selection for areas of newly establishing-Scots pine woodland suggests that any browsing damage to trees by hares is most likely to be a function of the local abundance of mountain hares, rather than a result of active preference of hares for the modified habitat.     

Spring and autumn habitat preferences of active European hares (Lepus europaeus) in an agricultural area with low hare density

The number of European brown hares (Lepus europaeus) has been declining throughout much of Europe since the 1960s. Consequently, many studies have focused on analysing habitat selection of European hares in order to improve the suitability of the habitat for this species. Habitat preferences of European hares are known to be affected by hare density, but most studies have been conducted in agricultural areas where hare densities were medium to high. Finding habitat preferences at high densities is difficult as most available habitats are occupied. In addition, in agricultural areas, field size might influence the hares’ habitat selection because it affects the distribution and availability of certain habitat types. However, most studies relate to areas with large field sizes. In this study, we analysed the habitat preferences of European hares in spring and autumn during the activity period, in the early hours of the night, in an agricultural area with low hare density and small average field size using Chesson’s electivity index. Moreover, we focused on the question whether two different habitat classifications varying in their specificity might cause contradictory results regarding European hares’ habitat preferences. Our results show that in this agricultural area with low hare density, European hares avoided several habitat types which were preferred in other study areas with higher hare densities. Therefore, we assume that hare density has an influence on the species’ habitat selection. In contrast, the small average field size of our study area seemed not to have an effect on hare habitat preference. Furthermore, by pooling habitat types into broader groups, substantial information was lost in some categories. Hence, for some categories, e.g. grassland or agricultural crop land, more detail might be needed than for others, such as urban areas, when analysing hares’ habitat selection. In conclusion, our results imply that studies on habitat preferences have to be conducted in areas with low hare density to be able to gain knowledge on the species’ habitat requirement and hereinafter improve the suitability of the habitat for this species.     

The distribution of mountain hares Lepus timidus in Europe: a challenge from brown hares L. europaeus?

1. Throughout the most recent glacial period (Weichsel), the mountain hare Lepus timidus had a continuous distribution in the tundra habitat south of the ice‐rim. When the ice retreated, mountain hares colonized deglaciated land, and spread over northern Europe. 2. Since the Weichsel, the mountain hare's distribution in Europe has been gradually reduced and at present comprises Ireland and the Scottish Highlands, high altitudes in the Alps, isolated forests in eastern Poland, most of Fennoscandia and from the Baltic countries eastwards through Russia. Declines during the last century have been observed in Sweden and Russia. 3. This review defines and evaluates causes for this gradual reduction and fragmentation of the mountain hare's distribution, with special focus on interactions with brown hares Lepus europaeus. The relative importance of diseases, predation, cultivation and interactions with other herbivores than brown hares are discussed. 4. A plausible cause of the possible permanent disappearance of mountain hares in Europe appears to be exclusion by interspecific competition and hybridization with, and/or epidemic diseases mediated by, the congeneric brown hare.     

European hare (Lepus europaeus) invasion ecology: implication for the conservation of the endemic Irish hare (Lepus timidus hibernicus)

European hare Lepus europaeus populations have undergone recent declines but the species has successfully naturalised in many countries outside its native range. It was introduced to Ireland during the mid-late nineteenth century for field sport and is now well established in Northern Ireland. The native Irish hare Lepus timidus hibernicus is an endemic subspecies of mountain hare L. timidus and has attracted major conservation concern following a long-term population decline during the twentieth century and is one of the highest priority species for conservation action in Ireland. Little is known about the European hare in Ireland or whether it poses a significant threat to the native mountain hare subspecies by compromising its ecological security or genetic integrity. We review the invasion ecology of the European hare and examine evidence for interspecific competition with the mountain hare for habitat space and food resources, interspecific hybridisation, disease and parasite transmission and possible impacts of climate change. We also examine the impact that introduced hares can have on native non-lagomorph species. We conclude that the European hare is an emerging and significant threat to the conservation status of the native Irish hare. Invasive mammal species have been successfully eradicated from Ireland before and immediate action is often the only opportunity for cost-effective eradication. An urgent call is issued for further research whilst the need for a European hare invasive Species Action Plan (iSAP) and Eradication strategy are discussed.     

Effects of arboriculture stands on European hare <Emphasis Type="Italic">Lepus europaeus</Emphasis> spring habitat use in an agricultural area of northern Italy

Habitat changes due to agricultural intensification is widely considered a main cause of European hare (Lepus europaeus Pallas, 1778) decline. We investigated the potential of arboriculture stands to enhance landscape diversity and increase farmland suitability for European hares in an intensive agricultural area of northern Italy. In spring 2005, we recorded hare habitat use during feeding activity and resting time by nocturnal censuses and searching for daytime resting sites, respectively. Hare presence/absence, based on faecal pellets, was assessed in 150 1-m radius plots. Hares positively selected edges and avoided woods and stubble during both feeding activity and resting time, which highlights the key role of permanent linear cover in providing the variety of vegetation types required by hares for shelter and feed. Forms were typically located in covered places, surrounded by denser vegetation than sample plots, in order to gain protection from avian and terrestrial predators. Arboriculture stands seem to be able to satisfy a part of hare habitat requirement, thanks to ground flora that provide tasty food, and tree cover that offers refuge against predators and bad weather conditions. However, more focused studies are necessary to improve knowledge of the long-term effects of these crops on farmland biodiversity.     

The recent expansion of the brown hare (<Emphasis Type="Italic">Lepus europaeus</Emphasis>) in Sweden with possible implications to the mountain hare (<Emphasis Type="Italic">L. timidus</Emphasis>)

The brown hare (Lepus europaeus) expanded its Swedish distribution since the 1980s northwards and locally to new areas within its former range. Of 115 brown hare populations within the former range reported in a hunter enquiry, those established after 1980 were situated higher above the sea level than older ones and higher than neighbouring (<50 km) older populations. Reports on increased use of forest habitats by brown hares were equally frequent among recent and older populations, suggesting a process promoted solely by less harsh winters. Supposed hare hybrids were more often reported from hunting grounds with recent brown hare establishment, i.e. where the species expands in time and in space. In a 27-year dataset on brown hare observations, the recent increased use of forest habitats was supported in that maximum distances to agricultural land for brown hare sightings were higher in mild winters, whereas the proportions of the annual observations made during winter were lower. In 40-year bag records from two Swedish counties, the dynamics of the mountain hare (Lepus timidus) responded positively to snow parameters, whereas brown hares responded negatively. We suggest that the state of mountain hare populations primarily depends on winter conditions and predation pressure, whereas possible effects of hybridization are unclear. If winter conditions remain as in the last 15 years, mountain hare numbers are not likely to increase in southern Sweden, whereas the brown hare may expand even further. In either case, hybrids will occur in sympatric areas in frequencies probably related to the density of the respective true species.     

The occurrence of mountain hare mitochondrial DNA in wild brown hares

If interspecific hybrids are fertile and backcross to either parental species, transmission of mitochondrial DNA over the species barrier can occur. To investigate if such transmission has occurred between the brown hare Lepus europeus Pall and the mountain hare L. timidus L. in Scandinavia, an analysis of genetic variation in mitochondrial DNA from 36 hares, collected from 15 localities, was performed. Sequence divergence of mtDNA between species was estimated at 8 ± 1% (SD). Intraspecific mtDNA sequence divergence varied between 0.09 and 0.38% in brown hares and 0.10 and 1.44% in mountain hares. In six out of 18 brown hares examined, two different haplotypes of mountain hare origin were detected, demonstrating a transmission of mtDNA haplotypes from mountain hares to brown hares. The results indicate that interspecific hybridization between the two species occurs in wild populations.     

Plant sex and hare feeding preferences

Summary To evaluate the general extent to which sex-related differences in palatability occur in boreal dioecious woody plants, males and females of five dioecious woody plant species were presented to free-ranging mountain hares (Lepus timidus) during winter. Hares strongly preferred branches from male plants when feeding on Populus tremula and Salix caprea and weakly preferred male S. pentandra. However, they did not show any sex-related preference when feeding on the other two species studied (Myrica gale and Juniperus communis). Nitrogen concentration and, to some degree, digestibility showed strong relationships with hare food preferences. By contrast, the concentration of phenolics was only weakly related to feeding preference. Phenolics could, nevertheless, still be important if only one or a few specific compounds deter hare feeding. These results indicate that sex-related differences in plant palatability in the boreal forest might be more widespread than previously believed, particularly for species of the family Salicaceae. Thus, herbivores might be responsible for the female-biased sex ratios found in willow populations in northern Scandinavia (e.g. Elmqvist et al. 1988).     

Patterns and potential drivers of intraspecific variability in the body C,N, and P composition of a terrestrial consumer,the snowshoe hare (Lepus americanus)

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The diet of the mountain hare (Lepus timidus hibernicus) on coastal grassland

Across most of their range in Europe, mountain hares are usually restricted to upland areas with poor food quality. In these areas they generally feed on browse species such as heather or twigs and barks of trees. On lowland areas in Europe, with better food quality, the mountain hare is replaced by the brown hare ( Lepus europaeus ) which feeds predominantly on greasses. This khas led some authors to conclude that mountain hares are primarily adapted for browsing. In the absence of brown hares in Ireland, mountain hares are found on a wide variety of habitats including grassland. On grassland, their diet consists almost exclusively of grasses, up to 94% of their annual diet, which is more than has been reported for brown hares on similar habitat. Based on this evidence, and other work, it is proposed that the mountain hare in primarily a grazing animal and competitive exclusion by brown hares may underlie much of their present distribution in Europe.     

Sexing European rabbits (Oryctolagus cuniculus), European brown hares (Lepus europaeus) and mountain hares (Lepus timidus) with ZFX and ZFY loci

We describe a new method for the sex determination of tissue originating from Oryctolagus cuniculus (European rabbit), Lepus europaeus (European brown hare) and Lepus timidus (mountain hare) based on PCR-RFLP analysis of point mutations that differentiate the ZFX and ZFY gene sequences. Among several applications, this PCR-RFLP method could be used to investigate gender ratio and evaluate the population dynamics of these species using samples collected when sex cannot be identified.     

Diurnal Habitat Relationships of Canada Lynx in an Intensively Managed Private Forest Landscape in Northern Maine

Abstract In March 2000, Canada lynx (Lynx canadensis) were listed as a federally threatened species in 14 states at the southern periphery of their range, where lynx habitat is disjunct and snowshoe hare (Lepus americanus) densities are low. Forest conditions vary across lynx range; thus, region-specific data on the habitat requirements of lynx are needed. We studied lynx in northern Maine, USA, from 1999 to 2004 to assess quality and potential for forests in Maine to sustain lynx populations. We trapped and radiocollared 43 lynx (21 M, 22 F) during this period and evaluated diurnal habitat selection by 16 resident adult lynx (9 M, 7 F) monitored in 2002. We evaluated lynx selection of 8 habitats at multiple spatial scales, and related lynx habitat selection to snowshoe hare abundance. Lynx preferred conifer-dominated sapling stands, which supported the highest hare densities on our study site (x̄ = 2.4 hares/ha), over all other habitats. The habitats where lynx placed their home ranges did not differ by sex. However, within their home ranges, males not only preferred conifer-dominated sapling stands, but also preferred mature conifer, whereas females singularly preferred conifer-dominated sapling stands. Approximately one-third of Maine's spruce-fir forest and nearly 50% of our study area was regenerating conifer or mixed-sapling forest, resulting from a disease event and intensive forest management (e.g., large clear-cuts). Our findings suggest that current habitat conditions in Maine are better than western montane regions and approach conditions in boreal forests during periods of hare abundance. We recommend that forest landowners maintain a mosaic of different-aged conifer stands to ensure a component of regenerating conifer-dominated forest on the landscape.