The bats at home in our attic

https://www.theguardian.com/environment/2016/sep/12/bats-attic-wales-country-diary

Version 0 of 1.

Nearly a century ago, someone bought part of the pasture at the end of the lane and built the house we’ve lived in for about a quarter of its life. This quiet spot faces east into the Cambrian Mountains and the builder cleverly oriented the house to ensure the best view from the front windows.

The steep pitch of the roof has proved popular with brown long-eared bats (Plecotus auritus), a colony of which has shared the house with us for the whole of our tenure. Accessing the loft space through a finger-sized gap between weather-board and tiles, these intriguing mammals are only a few centimetres long but have ears almost as long as their bodies.

Our loft has become a maternity roost in which they raise their young, emerging at dusk to voraciously scour the surrounding gardens and fields for incautious insects. Moths are especially favoured, and the bats often fly close to lighted windows to pick them off. They return before dawn, and we hear the scratch and skitter of their arrival on the tiles above our heads.

Three or four times each summer, members of the local bat group, stalwarts of environmental survey, assemble in our back garden just after sunset. As we sit on benches sipping mugs of tea, the bats crawl down over the tiles and launch themselves from above the gutter, becoming silhouetted briefly against the darkening sky. Bat detectors make audible their location-calls as the bats swoop past to check out their observers.

The counts have been encouraging, with the roost tending to grow at a gentle rate. Occasionally it drops sharply in size before increasing again, suggesting that a portion of the group heads off to form a new colony. On our final count this summer 39 individuals were spotted, close to our best result. Soon, the cold weather of autumn will render them torpid and they will slumber their way through the winter towards spring – a behaviour that I have occasionally envied.

•The Birds of North Wales, this year’s memorial lecture in honour of the late Country diary writer William Condry (thecondrylecture.co.uk), by Jonathan Elphick, is at Tabernacle/MoMA, Machynlleth, 1 October, 7pm for 7.30; £5 including refreshments (no need to book)