Three caves hewn into the rocky coastline of Dorset that are the bat equivalent of a speed-dating site, attracting crowds of the flying mammals from as far as 40 miles away, have been acquired by the National Trust.
The bats gather at Winspit caves near Swanage in the late summer and early autumn, dart around the cliffs and, if all goes well, find a mate from a different colony.
The National Trust said on Monday it had acquired the farmland that included the three caves, plus one inland.
“It’s effectively a big party when the bats arrive,” said David Brown, the National Trust ecologist for Purbeck. “They fly huge distances to favourite spots like this, mixing with bats from other colonies. The caves are also perfect for the bats to roost in, full of nooks and crannies.”
Fifteen species of bats had been recorded on the 350-acre Weston Farm site on the South Purbeck coast, making it Dorset’s most important “swarming site” – and one of national importance – with bats flying in from across the county and even farther afield to meet and mate on the wing.
The bats sweep into the three cliff caves – created by quarrying for Purbeck stone – from the seaside. They can also dart into another inland cave also created by quarrying. Brown said this “speed-dating” was important to ensure the genetic health of bat populations.
Among the creatures that are found there are the rare serotine and barbastelle bats. The caves are also used for winter hibernation for some of the UK’s rarest bats, such as the greater horseshoe.
The land forms the eastern half of St Aldhem’s Head, and will extend the existing trust-owned “Purbeck Wares”, an important habitat for orchids and other wildflowers. The coastal strip includes ancient “strip lynchet” terraced field systems.
Brown added: “We aim to create a landscape that is richer in nature, so there’ll be no chemical inputs or regular ploughing on any of the land and life will be restored to the soil using natural regenerative farming methods. As the land is given time to rest and recover, the ground will store more carbon and streams flowing off the land will be cleaner and healthier.”
Over the coming years, the farm, which has been in the same family for more than 100 years and through three generations, is to be transformed into a mosaic of species-rich grasslands, wildflower meadows, scrub and woodlands.
Conservation grazing of the grasslands sloping down to the coast should bring back plants such as the green-winged and early spider orchids.
Restored meadows on the former arable fields will hopefully bloom with cowslips and knapweeds, and these flower-rich grasslands will become home to rare butterflies such as the Lulworth skipper and adonis blue. This will also open up nesting sites for endangered skylarks.
Hedgerows, scrub and small woodland patches are intended to give refuge to voles and other mammals, and create breeding sites for birds including yellowhammers and linnets. This stretch of coastline is also the summer pit-stop for visiting birds such as whitethroats.
As well as being good for bats, the trust says it will improve access for human visitors. Brown said: “In the future people will enjoy fantastic uninterrupted access along a 7km stretch of some of the UK’s best coastline, and be free to explore some its most diverse and ecologically rich grasslands.”
