Another Life Michael VineyComing home happy from a night out with friends I found a sky suffused with moonglow and a bat at its station above the garden gate. There is always at least one such encounter in summer, when wine, night sky and bats conspire to a modicum of rapture.
I stood mesmerised as the bat flew in a long figure of eight, over and over, between me and the top of an old spruce tree. Every 10 seconds or so it would vanish, often to swerve from behind my right ear, like a conjuring trick, to resume its hunting pattern, presumably while chewing on a midge or moth. To trust absolutely to the animal's echolocation skills was to know the thrill of a knife-thrower's partner.
By day, it's the swallows that can test one's nerve a bit. We have waited a decade or more for the birds to discover the niches for swallow nests in our woodshed, which has two sides open to the air. Now, a walk to the gate must reckon with the swoopings in and out of a pair feeding a second brood. And when yet another party of south-bound migrants drops in at the acre for a feed of flies and midges - a regular occurrence in August - the residents start chasing the droppers-in, so that hectic squadrons of swallows go swirling tightly round the walls of the house and dashing through the trees.
Bats, as James Fairley points out in A Basket of Weasels, have the edge over birds when it comes to precision in flight, executing even tighter turns than swallows.
The bird has effectively only one finger, along the leading edge of the wing, with the flight feathers sticking out behind. It has relatively little direct control over changing the shape of the feathers, which themselves are as inert as hair. But the bat's wing is all living, elastic tissue, like the skin of a hand, and four fingers run through it to mould its shaping of the air.
No one fears that swallows will get tangled in their hair or suck their blood: primeval night-terrors die hard. But bats do insist on looking like flying mice, and close-ups of their faces have at best the glee of goblins (my drawing is of the lesser horseshoe bat, one of the species that hang upside-down at rest).
Bat consumption of insects is impressive - 3,000 or more on a summer night - and I think of Charles Moffat's description of Ireland's big, fast-flying Leisler's bats coming home "as hard as cricket balls" with all they've crammed into their bellies. But even people who grant bats a useful role in nature, and would regret their decline, can get fidgety about having them upstairs.
Most bats that use people's houses in summer are the pipistrelles, with a wingspan of about 22cm (but, with wings folded, one can fit into a matchbox).
Just like nesting swallows, their nursery colonies in warm roof-spaces are seasonal visitations - maternal roosts of bat mothers, each of which has a single baby in July. The young are licked over, and join their mothers in chirping calls for mutual recognition.
Young pipistrelles develop rapidly and can fly at about three weeks - about now, in fact - though suckling continues for another week or two. They learn to fly in a now-or-never way, pushed out at the exit by weight of numbers and spreading their wings as they fall. When a young bat returns from an early foray, it may miss the entrance to the roost and pick the nearest open bedroom window. It is far more frightened than you are, and thrashing about with a pillow will not help.
Bats don't bring in straw or twigs to nest and don't chew wiring (their teeth are quite different from those of rodents). Their droppings dry out and disintegrate, but the urine from a big colony can sometimes smell rather strong.
The ever-increasing local bat groups of Ireland use electronic detectors to identify Ireland's nine species from the differences in their ultrasonic echolocation sounds in flight (children can hear sounds up to 20 kiloherz, but the pulses from our bats are pitched much higher than that).
Always keen to share their enthusiasm, they have launched an umbrella organisation, Bat Conservation Ireland (www.batconservationireland.org). Funded by the Heritage Council, it provides a summer service, the Batline, which offers help and information by phone and e-mail (046 9242882 and batline@eircom.net), posts out bat-packs, and even makes house calls.
The best reading about Ireland's nine species of bat and the latest research into their lifestyles is in James Fairley's book A Basket Of Weasels, published privately in 2001 (£17). His address is 15 Luxor Gardens, Belfast BT5 5NB.