Mountain hare

Overall vulnerability

Feature(s) assessed:

• Mountain hare (Lepus timidus)

Special qualities:

• Internationally important and locally distinctive wildlife and habitats

Feature description:

The mountain hare is the UK’s only native lagomorph. It is easily recognised by its small ears with black tips, white tail, grey-brown coat in summer and a white coat in winter. Found in upland habitats, particularly heather moorlands, it was reintroduced to the PDNP for hunting in the late 1800s. The current population is divided by roads and river valleys into three main subpopulations. The PDNP is an important stronghold for this species, containing the only surviving reintroduced mountain hares in England.

How vulnerable are mountain hares?

Mountain hares in the PDNP have been rated ‘high’ on our vulnerability scale. This score is due to high sensitivity and exposure to climate change variables, coupled with a moderate current condition, and with a moderate adaptive capacity.

Currently with a declining population, mountain hares are particularly vulnerable in winter as energy demands are high. Healthy habitat for shelter and food are vital for the continued survival of this species. While this is an isolated population, the high population growth rate of mountain hares gives them a good chance at recovery from climate change events.

##Current condition: The PDNP mountain hare population has increased significantly since re-introductions in the 1800s. However, recent surveys by Sorby Natural History Society and other organisations suggest there has been a decline over the last decade. This is possibly due to the culls that are sometimes carried out in an attempt to minimise louping ill virus transmission to red grouse. While mountain hares themselves are no longer hunted for sport, culling is still taking place in some areas under game management laws. Populations are known to be cyclic, with losses of up to 90% every 5-15 years, but experts suggest the current decline is beyond this normal cycle. Total population estimates are difficult as they are extrapolated from a limited number of sightings that are used to calculate habitat density estimates. A 2018 study estimates 1,500-5,000 individuals in the PDNP. Other studies indicate it is likely to be at the lower end of this.

Land management such as heather burning and grazing can affect mountain hare populations. Heath and cotton-grass habitats containing a range of food plants are favoured over grasslands. While mountain hares show a preference for young heather growth, they can also survive on old heather stands and birch or willow scrub. A mixture of heather growth created through controlled burning may enhance foraging habitat. On the other hand, eroded areas of bare peat lack vegetation for food and shelter. Wildfires continue to pose a threat to the upland habitat needed by this species.

Other risk factors for mountain hares are predation and disease. Foxes and stoats are the main known predators, while birds of prey may take some young. Diseases such as louping ill virus and intestinal parasites may cause body condition to deteriorate and lead to the loss of some individuals and poor fecundity in others. Some individuals are also lost as road casualties.

What are the potential impacts of climate change?

Overall potential impact rating

Direct impacts of climate change

Wetter winters with cold snaps and persistent heavy rain pose a threat to mountain hares. While they do well in the current climate in England and Scotland, their fur is poorly adapted to being wet making them prone to increased heat loss when they are exposed for long periods. Mountain hares have limited cover to shelter in on cold wet days, which further increases their mortality risk. Extremely wet winters could lead to the loss of some mountain hares. Data Certainty: Moderate

Hotter, drier summers on the other hand are likely to benefit mountain hares. Increased temperatures have been associated with higher breeding success. Coupled with the possibility of an extended breeding season, it seems probable that mountain hare populations will increase in the PDNP during the warmer months. Data Certainty: Moderate

The predicted rise in carbon dioxide in the atmosphere and longer, warmer growing season may lead to increased plant growth rate in some areas. Increased vegetation that provides additional shelter and foraging is likely to benefit mountain hares right across their range. Shelter that protects them from extreme weather and predators along with the increased food availability could lead to a population increase. Data Certainty: Low

Human behaviour change

Land use changes and management decisions would affect mountain hare habitat and local populations. Dependent on certain food plants such as heather, changes to this vegetation mosaic could have both positive and negative impacts on mountain hares. Where there is increased grazing and loss of vegetation cover, population decline is likely. However, where there is favourable land management that optimises shelter and food options, populations are likely to remain stable or increase. Data Certainty: Moderate

Mountain hares are sensitive to disturbance, particularly during the winter months. With increased tourist numbers anticipated year-round in the PDNP, mountain hares are more likely to be disturbed by people out on the moors. One European study has shown that increased disturbance causes increased stress and creates higher energy demands as mountain hares are flushed out of their resting spots interrupting key activities such as grooming and the re-ingesting of faecal pellets. Higher energy demands in winter when food is already limited may be detrimental to the survival of frequently disturbed individuals. Data Certainty: Low

Other indirect climate change impacts

Warmer winters with reduced snow cover may increase the predation risk for mountain hares. The white winter coat is the perfect camouflage in a snowy landscape, but it stands out against exposed vegetation leaving them more vulnerable to predation. Temperature regulation in warmer winters may also be a challenge with their winter coat. Population decline in areas with little or no snowfall is probable. Data Certainty: Moderate Mountain hares and their habitat are sensitive to wildfire. Hotter summers with increased drought events create a higher risk of wildfire in the uplands, especially in areas dominated by heather. Large areas of mountain hare habitat are at risk and mountain hares may be lost in fires. Data Certainty: Low

Invasive or other species interactions

Disease outbreaks and predation levels may increase with year-round warmer temperatures. Lagoviruses that affect rabbits and hares have the potential to spread quickly as populations overlap in some areas. Pockets where both rabbits and mountain hares are present have a higher infection risk that could negatively affect local populations. Survival rates of ticks, pathogens, and predators may all be increased by the warmer temperatures. An increase in disease outbreaks and predation is likely to lead to population decline in affected areas. Data Certainty: Moderate

Sedimentation or erosion

Vegetation cover is vital for mountain hares as shelter and as a food source. Erosion caused by heavy rain poses a threat to this habitat as areas of vegetation and peat may be washed away leaving only exposed ground. As mountain hares are less comfortable using areas of bare peat, their habitat size may be reduced. In areas of extreme erosion populations may become more fragmented or even lost. Extreme events such as flooding and drought would worsen the situation, further altering the habitat extent and possibly causing the loss of some mountain hares. Data Certainty: Low

What is the adaptive capacity of mountain hares?

Overall adaptive capacity rating

The mountain hare is confined to three main subpopulations in the PDNP. Reintroduced to several places in England and Wales, the PDNP population is the only one that survived. The population is isolated in this upland environment and depends on specific habitat conditions in both summer and winter in order to survive. There is limited space to expand. However high population growth rates give them good resilience in recovering from population crashes. Disease and harsh weather events may be overcome if remaining individuals have a successful breeding season. Damage to or loss of habitat is likely to affect adversely their recovery and may even make it impossible in some areas. Data Certainty: Moderate

Mountain hares are protected under the Wildlife and Countryside Act (1981), where killing, injuring or taking in the closed season are an offence. They are listed in Annex five of the EC Habitats Directive as a ‘species of community interest whose taking in the wild and exploitation may be the subject of management measures’. They are also a priority UK Biodiversity Action Plan (UK BAP) species. This gives them additional protection and encourages conservation action by relevant local authorities. Data Certainty: High

Land management and habitat availability play a significant role in determining mountain hare distributions and population survival rates. Various organisations such as the National Trust and PDNPA manage and restore moorlands with the aim of increasing vegetation cover and reducing erosion. While funds are not specifically designated for mountain hare conservation, habitat maintenance and improvements are likely to help mountain hares partially overcome climate change effects. Mountain hare sightings data may help with long-term population monitoring and management responses. Data Certainty: High

Key adaptation recommendations for mountain hares:

Improve current condition to increase resilience

The current condition of a feature is an important factor alongside its sensitivity and exposure, in determining its vulnerability to climate change. These recommendations are aimed at improving the condition of the feature at present, therefore making it better able to withstand future changes to climate.

• Work with partners to reduce or end culling of hares in PDNP.
• Continue moorland restoration work to reduce bare peat and improve mountain hare habitat.
• Continue to gather mountain hare sightings data and encourage the public to report sightings. This will help inform future adaptation planning.
• Set up a mountain hare monitoring plan: to better understand local population dynamics and to identify risks, opportunities and key areas. Further research is required.
• Predator control could be a useful tool in high predator density areas, but may inadvertently increase predator populations and disrupt other species interactions. Research is needed to determine if a more natural system would be a better option for the future.
• Develop fire contingency plans, and ensure management of habitats reduces fire risk e.g. rewetting and increasing species or structural diversity. Influence visitor and behaviour management plans and practices to minimise ignition risk.
• Encourage further uptake of environmental land management schemes by farmers within the PDNP.

Improve current condition to increase resilience: Targeted conservation efforts for important sites and at risk areas

The current condition of a feature is an important factor alongside its sensitivity and exposure, in determining its vulnerability to climate change. These recommendations are conservation measures aimed at those sites that will have the biggest impact for this feature – either because they are particularly important for the feature or because they are most at risk from climate change.

• Limit disturbance at known sites: particularly in areas with high visitor numbers.
• Install wildlife corridors, such as underpasses, to increase connectivity between populations and decrease road casualties.