Battle for the bats: A species under threat in Cambridge from planning applications

With planning applications threatening the city’s bat populations, Bob Jarman hunts for bats by the river.

I don’t know much about bats, but what little I do know comes from annual guided bat walks to Byron’s Pool and Paradise Local Nature Reserve. The walks are led by two bat experts from the Wildlife Trust – Anita Joysey and David Seilly.

The most recent guided walk, at the end of August, attracted about 25 “batters” and was the best I have been on.

We saw five species in the gloom as night advanced: noctule bats above the trees as big as blackbirds, serotines like flighty robins between the trees, common and soprano pipistrelles flashed over our heads and between us and daubenton’s bats flew low and fast over the river, like nocturnal swallows, snatching insects from the water’s surface.

Three other species of bats emerge later: natterer’s, brown long-eared bats and the very rare barbastelle.

Even with my novice bat detector I could hear the terminal buzz, like “blowing a raspberry”, of the pipistrelles’ echolocation, as they caught a flying insect.

“Paradise is good for foraging bats, there were eight species discovered in a recent survey. You would be hard pressed to find more species, in one place,” said David Seilly.

But these bats are under pressure and our insects are in severe decline.

Queens’ College has submitted a planning application to build four student accommodation blocks containing 60 rooms, car and cycle parking, refuse and other storage and a new electricity substation, within outbuildings in the gardens of Owlstone Croft, next to Paradise Nature Reserve.

Bats and roosting birds are affected by peripheral light and this development may have a critical effect on their distribution and occurrence in the reserve.

Paradise Nature Reserve is managed by the Friends of Paradise and Cambridge City Council. It is probably the most diverse habitat of our riverside nature reserves which include Byron’s Pool and Logan’s Meadow. The first planning application by Queens’ College was refused, but supported by the chair of the planning committee and officers of the council. This refusal has been the subject of an appeal hearing, with the result not yet known.

“According to the plans, five trees on the building development side of the reserve will be felled, but these are an important part of the bats’ feeding corridor,” said Anita Joysey. “We should not just be concerned about the bats, but insects being drawn away from the reserve by bright lights will also affect insectivorous birds, of which we have good populations in Paradise. The insects are also important in their own right and have in recent years suffered severe declines in populations.”

The Friends of Paradise have lodged a vigorous case against this development by Queens’ College and commissioned a Bioscan bat survey which proved the existence of the eight distinct species of bats. Barbastelle bats are especially rare, and they use Paradise Nature Reserve and Adams Road Reserve, but do not breed at either.

The Friends of Paradise have launched a fund to support their case against this building development.

At Paradise Nature Reserve, these lights will draw night-flying insects out of the reserve causing a reduction in food available for the nocturnal bats. It is the same situation at a nearby nature reserve in Adams Road, where another planning development will affect the integrity of the reserve and its bat population, due to peripheral night-time light.

These developments are against the background that the UK is one of the most nature depleted countries in the world, according to the World Wildlife Fund. More than 40 per cent of our species are in decline.

There comes a time when we have to say “no” to developments that affect our natural history. There comes a time when we must grant wildlife, its habitats, and the ecology of our natural systems a priority.

Within Cambridge, we risk losing green space and green belt land which in turn piles on pressure to develop yet more adjacent land, especially in the north and east of the city.