Look harder to spot animals in their winter camouflage

WE HAVE reached the point in the season at which most mountain hares – also known colloquially as white hares and snow hares – have begun to merge with the winter landscape.

For much of the year the mammal’s pelage, or fur, is brown, although greyer than its more common relative the brown hare. But when temperatures plummet this turns mostly white to provide effective camouflage in its upland habitat against predators like foxes, common buzzards and, now less of a threat than at one time, humans.

Although principally associated with the Scottish Highlands in the UK, the mountain hare also occurs in small numbers in West and South Yorkshire and has its main English stronghold in Derbyshire. The mammal was once native to the British Isles but disappeared from England centuries ago until reintroduced in the Peak District for sporting purposes between 1870 and 1882.

Thanks to a recent study commissioned by the Peak District-based Moors for the Future Partnership, we now have a clearer idea of where it can be found. The study was carried out by the Stockholm Environment Institute, which encouraged members of the public to report sightings via the internet or by using special tablet and smartphone apps. The information given included precise locations and numbers of mountain hares observed.

A distribution map resulting from the study shows a sighting on moorland above Marsden in the Colne Valley west of Huddersfield, a greater presence on Meltham Moor to the south, and yet bigger numbers around Black Hill and the Holme Moss transmitter at the head of the Holme Valley. Some of the highest concentrations are on the Midhope and Bradfield Moors near Sheffield.

Across the survey area of the South Pennines and Peak District, just over 500 individual mountain hares were seen between 2015 and last year, suggesting a sharp decline in numbers since a survey of more or less the same areas back in 2000 recorded 1,385 mountain hares. This is in line with a dramatic drop in the population of Scotland’s mountain hares.

The Moors for the Future report found that the change to white coats appeared to start in October and November, then peak in January and February before the moult to brown fur synchronised with the melting of snow in late winter and spring.

A warning about the possible effects of climate change is sounded in the report. “If snow fall decreases in future,” it says. “Mountain hares may become increasingly vulnerable to predation if they continue to change their coat colour to white but there is no snow.”

Sadly, the best chance which most people have of seeing one with its snow camouflage is as roadkill. A Peak District National Park ranger told me a few years ago that mountain hares seem to be drawn onto roads at night because the surfaces retains some of the heat they acquire during the day.

“The hares don’t have a lot of road sense,” he said. “And in the evening they are squashed. There are loads of fatalities.”