The effect of landscape heterogeneity on population density and habitat preferences of the European hare (Lepus europaeus) in contrasting farmlands

Adaptation of farmland mammalian specialist to urban life: Escape behavior of European hare along the urban-rural gradient

The European hare Lepus europaeus is an iconic but rapidly declining farmland specialist with recently confirmed populations in urban areas. However, their behavioral responses and adaptability to urbanization and life in human-dominated areas are fully unexplored. Here, using infrared cameras, we explored escape behavior (measured as the flight initiation distance) using 965 hare observations in urban and farmland areas in the Czech Republic and Austria (Central Europe) and its association with habitat type, distance to the city center, patch size, season, hare age and initial behavior. We found that European hares adjusted their escape behavior to habitat type and escaped significantly earlier in farmland (rural) habitats than in urban habitats. However, escape distances of hares did not differ between farmland types with different degree of habitat heterogeneity. We also revealed that urban hares escaped earlier when located further from the city center or in a larger study patch. Moreover, adult hares escaped earlier than subadults and foraging individuals escaped earlier than resting hares but both only in rural areas. Our results support high behavioral adaptability of European hares to human-dominated urban areas.

The low survival rate of European hare leverets in arable farmland: evidence from the predation experiment

The low survival rate of leverets may significantly contribute to steep population declines and slow recovery of European hares (Lepus europaeus). However, the leveret survival rate in farmlands with different landscape structures is poorly understood, and the existing evidence comes mainly from Western Europe. In this study, we explored the survival of leveret hare dummies along linear semi-natural habitats in homogeneous Central European arable farmland during the main part of the European hare reproduction period (March-April) in 2019 and 2020. The survival rate of hare leverets during the 14-day period was only 22.2%, and all predation events were recorded during the first six days of the experiment. Mammalian predators were responsible for 53.1% of predation events, avian predators for 40.8%, and agricultural operations for 6.1%. The red fox (Vulpes vulpes) was the dominant predator in our study area and was the primary cause of leveret dummy mortality (32.7%), but it also had the highest use-intensity and visit frequency of all of the study plots. Predation by avian predators was associated with patches of lower vegetation height and cover (such as plowed fields) and during daylight hours, whereas the opposite was true for mammalian predators. We propose that improving the habitat quality of arable landscapes by increasing the proportion and quality of extensively used non-farmed habitats (e.g., set-asides, wildflower areas, extensive meadows, fallow land, and semi-natural habitats on arable land) providing cover and shelter for leverets could be an effective management measure for reducing predation risk on leverets.

Pathomorphological Findings and Infectious Diseases in Selected European Brown Hare (Lepus europaeus Pallas, 1778) Populations from Schleswig-Holstein, Germany

In the northernmost German federal state Schleswig-Holstein, populations of European brown hares (Lepus europaeus Pallas, 1778) show diverse densities and varying courses over the years. To examine differences in pathomorphological findings and infectious diseases as possible reasons for varying population dynamics, we assessed 155 hunted hares from three locations in Schleswig-Holstein from 2016 to 2020. We investigated the association of location, year, age, and sex of animals to certain pathomorphological findings and infectious diseases. Frequent pathomorphological findings were intestinal parasites (63.9%), hepatitis (55.5%), nephritis (31.0%), steatitis (23.2%), enteritis (13.5%), and pneumonia (5.2%). Body condition differed significantly between locations, and the prevalence of pneumonia was significantly higher in females. Enteritis was not detected in 2019, when much more juveniles were sampled. Hepatitis and nephritis occurred significantly more often in 2016 and among adults. Additionally, more adults showed hepatitis with concurrent serotitre for European brown hare syndrome virus (EBHSV), while intestinal parasitosis as well as high excretion rates of coccidia were more common in juveniles. Sampled animals showed high infection rates with Eimeria spp. (96.1%), Trichostrongylus spp. (52.0%), Graphidium strigosum (41.2%), and a high seroprevalence (90.9%) for EBHSV, without severe symptoms. This study revealed a low prevalence of infectious pathogens, but a high prevalence of chronic inflammations of unknown origin in the tested brown hare populations. Overall, our results indicate a rather minor importance of infectious diseases for observed population dynamics of analysed hare populations in Schleswig-Holstein.

Status of Infectious Diseases in Free-Ranging European Brown Hares (Lepus europaeus) Found Dead between 2017 and 2020 in Schleswig-Holstein, Germany

The European brown hare (Lepus europaeus) is a quite adaptable species, but populations have been decreasing for several decades in different countries, including Germany. To investigate infectious diseases as possible influences on observed population decline in the German federal state Schleswig-Holstein, 118 deceased free-ranging European brown hares were collected between 2017 and 2020 and underwent detailed postmortem examination with extended sampling. Infectious diseases were a major cause of death (34.7%). The number of juveniles found exceeded the adult ones. The main pathomorphological findings were hepatitis (32.8%), pneumonia (22.2%), nephritis (19.1%), liver necrosis (12.9%), and enteritis (40.7%). An unusual main finding was steatitis (20.9%) of unknown origin. Animals were mainly emaciated and showed high infection rates with Eimeria spp. (91.3%) and Trichostrongylus spp. (36.2%). European Brown Hare Syndrome Virus reached an epidemic status with few fatal infections (4.2%) and high seroprevalence (64.9%), whereas the prevalence of Rabbit Haemorrhagic Disease Virus 2 was very low (0.8%) in hares in Schleswig-Holstein. Pathogens such as Yersinia pseudotuberculosis (5.9%), Pasteurella multocida (0.8%), and Staphylococcus aureus (3.4%) only caused sporadic deaths. This study illustrates the wide distribution of various infectious pathogens with high mortality and even zoonotic potential. Infectious diseases need to be considered as an important influence on population dynamics in Schleswig-Holstein.

New agri-environmental measures have a direct effect on wildlife and economy on conventional agricultural land

The objective of this article is to evaluate economic profits along with return on investment and also the impact of newly designed agri-environmental measures (AEM) on the presence of bioindicator species-European hare and roe deer-in comparison to conventionally cultivated agricultural land. The abundance of European hare was, on average, 4.5-6.7 times higher on AEM compared to the standard agricultural regime and 3.5-6.4 times higher in the case of roe deer in 2020 and 2021. From an economic point of view, the highest incomes were found for extensive orchard alleys and standard conventional crops-wheat and rapeseed rotation. The cash flow from extensive orchard was 4.3 times larger and wheat and rapeseed were 3.5 times larger than from the clover grass mixture. Moreover, the lowest value of operational expenses was found in the case of extensive orchard alleys. The payback period ranged from 16.02 years (wheat and rapeseed rotation) to 53.6 years (clover grass mixture). It is crucial not to assess the economic parameters separately but optimize them with sustainable wildlife management and other benefits that provide ecological and efficient directions of AEM for future generations. However, the performed economic analysis highlights the significantly lower incomes of most components of AEM. We see a principal issue of AEMs usage in the lack of strong incentives for farmers to maximize conservation outcomes. Therefore, the AEMs are often placed in locations with presumed low agriculture profit, which is often related to insignificant conservation effects. Thus, the incomparable AEMs profitability compared to conventional agriculture has to be reflected by the agricultural policy at the European Union level and subsidy policy of particular member states.

Helminth biocoenosis of Lepus europaeus meridiei (Hilzheimer, 1906) from Pianosa island, Italy

Pianosa is a 10 km² Italian island in the Tyrrhenian Sea which is part of the Tuscan Archipelago National Park. In this island lives a brown hare population which, according to the literature, belongs to the ancestral taxon Lepus europaeus meridei that offers a unique opportunity to observe how the parasite biocoenosis shapes in condition of isolation, limited space availability and high population density. The aim of this work is to describe the helminth component community of a non-managed, isolated, and dense hare population, evaluating host-parasite relationship and parasite community structure. All 26 analyzed hares (13 males and 13 females) were in good physical conditions, and all of them harboured exclusively the nematode Protostrongylus oryctolagi only. This is the first report of this lungworm species in Italy. The estimated overall abundance was 48.15 worms per examined hare (range 3-258, median 50) and the parasites were unevenly distributed across host population, with few hosts having most parasites (aggregated or overdispersed distribution). No significant relationship was detected between the number of isolated parasites and hare sex and weigh. The effect of the isolation of Pianosa's hare population seems to have acted reducing parasite richness, while the high host density is probably the cause of the high prevalence and abundance of the single helminth species collected. In conclusion, despite the low impact of parasites confirmed also by the overdispersed parasite distribution, the low diversity of the studied parasite community sounds a warning for the management of the hare population and the whole Pianosa's ecosystem.

Surveillance and habitat diversity affect European brown hare (Lepus europaeus) density in protected breeding areas

The European brown hare (Lepus europaeus) is an important game species throughout Europe. In Italy, for preventing the introduction of allochthonous strains, the management of brown hare populations has focused on the establishment of small protected areas (ZRCs), appositely managed for disposing of wild-born hares for restocking hunting territories. We investigated the effects of both land cover and surveillance on hare density and habitat preferences in 20 ZRCs, monitored twice per year (pre- and post-breeding periods) between 1997 and 2017. Density, as assessed by spotlight counts, ranged between 2.8 and 47.0 ind/km2 in spring and 5.0 and 68.4 ind/km2 in autumn. Surveillance, percent length of protected boundaries, year of institution and habitat diversity, as assessed by Shannon’s Index, were the main factors affecting hare density. During their foraging activity, hares selected ryegrass, hayfields and lucerne, while avoided maize stubble and ploughed fields and were never recorded in poplar plantations or next to human settlements. While the effects of habitat heterogeneity on hare density have been widely studied, we suggest that the involvement of local stakeholders may be of paramount importance for ensuring effective conservation measures.

Habitat requirements of the European brown hare (Lepus europaeus PALLAS 1778) in an intensively used agriculture region (Lower Saxony, Germany)

Background

The European brown hare (Lepus europaeus) typically resides in open habitats in agriculturally dominated landscapes in Europe. Over recent decades, a widely observed population decline occurred, which was attributed to agricultural intensification. However, with political incentives for specific crops, especially maize for energy production, the habitat went through massive changes. Thus, there is the need to identify parameters that characterize a suitable habitat for the brown hare in today’s agricultural lands.

Results

We modelled European brown hare densities spatially and temporally explicit over 10 years (2005–2014) across an entire federal state. The generalized additive mixed model confirms a constant decline of the European brown hare population in Lower Saxony. Municipalities with a high proportion of grassland and precipitation totaling up to 900 mm are more favored. Woodland showed an approximately linear negative effect. The most important agricultural crop groups such as winter grains and winter oilseed rape showed overall positive effects on hare densities. However, the effect of maize was unimodal, with a positive effect of medium proportions, but a negative effect of very high proportions. The effect of sugar beet was relatively weak but negative. Brown hares were also more abundant in municipalities with a higher density of vixen with litter and municipalities with a high proportion of wildflower strips showed higher brown hare abundance.

Conclusion

Lower Saxony is a diverse federal state with grassland dominated areas in the northwest, more woodland in the east, but intensive arable land in most remaining areas. The European brown hare—a species with a wide ecological potency—shows preferences to both grassland and the most typical arable crop groups such as winter grains and winter oilseed rape. The substantial increase in maize production within the time frame was likely unfavourable and may be one reason for the decline. Nonetheless, political tools such as the agri-environmental scheme “wildflower strips” were beneficial for the brown hare abundance and may be an option to reverse the decline seen over the 10 years.

Electronic supplementary material

The online version of this article (10.1186/s12898-019-0247-7) contains supplementary material, which is available to authorized users.

First findings of brown hare (Lepus europaeus) reintroduction in relation to seasonal impact

In Europe, brown hare (Lepus europaeus) populations have been declining steadily since the 1970s. Gamekeepers can help to support brown hare wild populations by releasing cage-reared hares into the wild. Survival rates of cage-reared hares has been investigated in previous studies, however, survival times in relation to seasonality, which likely plays a crucial role for the efficacy of this management strategy, has not been evaluated. Here we examine the survival duration and daytime home ranges of 22 hares released and radio-tracked during different periods of the year in East Bohemia, Czech Republic. The majority of hares (82%) died within the first six months after release, and 41% individuals died within the first 10 days. Significant differences were found in the duration of survival with respect to the release date. Hares released in the summer months (July and August) survived the longest (on average 103.2 days, SD ± 23.8) and hares released throughout all other months of the year survived for significantly shorter periods of time (on average 20.4 days, SD ± 11.5). The most likely cause of death was red fox predation (38.9%) followed by disease (coccidiosis and other health problems) (27.8%). Three hares (16.6%) were killed by automobile traffic. After six months of radiotracking, we found the average survival time of all hares released was 58 (SD ± 70.9) days. Hares in this study preferred to remain in the vicinity of the release area and the average distance from release point to the center of the home range was 471 m.