The brown long-eared bat is a common and widespread species second only to the pipistrelle in distribution both nationally and in Suffolk.
Extremely long ears, which can sometimes be partly curled like a ram’s horn, makes them easily distinguishable from other Suffolk species.
In hibernation, close examination may reveal the ears folded back beneath the wings, but the long ear lobe known as the tragus remains erect, looking like a small ear.
This species is found in a wide variety of sites from modern houses, churches to timber framed barns and including ice houses and chalk tunnels.
It is the only species regularly found both in summer and winter.
They readily use bat boxes and some 65 animals were discovered in one Thetford box a few years ago!
Nursery colonies are usually located within lofts where the animals cluster along the ridge board, giving rise to a characteristic line of droppings on the loft floor.
They have a characteristic slow, fluttering flight with occasional hovering pauses and are more frequently seen than heard because of their very quiet echolocation sounds picked up by bat detectors.
Moths form a significant part of their diet but they are also able to glean other insects, such as flies, from foliage.
Once caught the prey is taken to a favourite perch, often a porch or similar covered site where the only evidence of bat activity will be a pile of discarded moth wings and occasionally a few droppings on the floor.
Brown long eared bats rarely cross areas of open ground and tend to forage within 1-2km of the roost site using hedgerows, tree lines and banks as navigation routes. Destruction of such features may well have a negative impact on the species by isolating the feeding areas from the roosts. In addition, their habit of flying low and picking prey off the ground means they may fall prey to cats. In some cases the cats become very adept at catching bats and over the course of a summer one animal can seriously deplete a colony.
Like other bat species adapted to living in houses they are susceptible to disturbance from building work and to chemical sprays used in timber treatment.
All bats are protected by law and advice should be sought from Natural England if there is any likelihood they could be affected by building works or tree felling.
For more information about the Suffolk Wildlife Trust and its nature reserves, visit www.suffolktrust.org