Chevin Forest Park GeoTrail #10: Long-Eared Bat
The 10th cache in the series, a camo-taped pre-form tube, is located at the top of The Chevin ridge at a location with a great panoramic view to the south and south-east.
For background info on the Chevin Forest Park and the series, including a map showing parking options, trails and cache locations, see GCB7RA1.
If you are in the right place (especially around the White House and adjacent fields) at the right time, one of the creatures you may be able to spot on The Chevin is . . . the Brown Long-Eared Bat (Plecotus auritus). The best time to see it is an hour or more after sunset (later than most bats), when it leaves its roosts to hunt. It usually follows linear features like streams, fences and hedges, and flies somewhat slower than other bats.
This elusive bat is one of the UK’s most fascinating yet little-known mammals and plays an important ecosystems role, helping to control insect populations and providing key indicators of environmental health.
It is immediately recognisable by its huge ears, which are up to 4cm long and nearly as long as its body. However, at rest, they are often folded back or tucked beneath its wings, making them less obvious. Each ear has 24 distinctive folds on its surface, believed to help funnel sounds more effectively.
The eyes are large and bright, positioned above a bulging nose on a pinkish brown face. Its fur is soft, light brown on the back, more yellow-brown on the undersides, its wingspan is around 23-30 cm, and its body length is just 4-5 cm.
Adults weigh 12g in autumn at their heaviest just before they begin hibernation in winter roosting from November to April, hidden away in tunnels, caves and mines. They lose up to half of their body weight before emerging in Spring.
They emit sharp clicks and chirps while hunting at the ultrasonic range of 25-50 kHz, which is weak for bats, making them hard to hear with a bat detector – hence the nickname ‘whispering bat’.
It is widely distributed across the UK, favouring woodland, parkland, gardens, and older buildings. It needs both suitable roosting sites and good foraging habitat and is often found in ancient/light woodland and hedgerow networks that provide shelter, flight corridors, and rich sources of insect prey. It often roosts in tree holes, barns, attics, and old churches. Summer roost colonies are large and can contain up to 50 bats - both males and females.
It is primarily insectivorous, feeding on moths, beetles, flies, and spiders, capturing smaller prey mid-flight or gleaning it from leaves and bark. Larger prey is taken to a perch and consumed while upside-down. It may visit gardens looking for food, but avoids built-up areas.
What sets it apart from many other bat species is its method of hunting. Rather than relying on echolocation only, it uses its excellent hearing to detect faint rustles of insects in vegetation.
Mating usually takes place in late summer or autumn, but fertilisation is delayed until spring. Females gather in maternity roosts of up to 30 pregnant bats during the later spring warmer months and give birth to a single pup in late June or July. The young are weaned and fly within 3-4 weeks. It can live for >20 years in the wild, although most reach only 4-5 years due to predation and habitat loss.
It is relatively common, but populations are still vulnerable to changes in land use, agricultural intensification, and loss of roosting sites. The related grey long-eared bat found in the far south is one of the rarest mammals in the UK, with possibly <1,000 left.
Conservation efforts focus on protecting roost sites, maintaining and restoring suitable foraging habitats, and improving public awareness. Initiatives such as agri-environment schemes and organisations like the Bat Conservation Trust have been vital in promoting bat-friendly environments.
See short videos here, here (ID guide) and here.
