Bats are the only true flying mammals. They are insectivorous (eat insects), and contrary to popular misconception they are not blind; many can actually see very well (6). All British bats use echolocation to orient themselves at night; they emit bursts of sound that are of such high frequencies they are beyond the human range of hearing and are therefore called 'ultrasound' (7). They then listen to and interpret the echoes bounced back from objects, including prey, around them, allowing them to build up a 'sound-picture' of their surroundings (7). Brown long-eared bats produce echolocation calls at frequencies between 25 and 50 kHz, which are very quiet, and have earned the species the alternative name of 'the whispering bat' (5). They emerge only after nightfall (2), and their broad wings allow them to fly slowly, but with high manoeuvrability (5). They hunt for flying insects such as moths, beetles and flies whilst on the wing, but also take spiders, earwigs and other invertebrates from leaves or tree bark (known as 'gleaning'), and may even land on the ground to deal with awkward prey (5). Their sense of hearing is so acute that they can home in on prey by listening for the sounds made by the insect as it moves around; they can also hunt by sight (5). Large prey items may be taken to a perch, which can be identified by the heap of insect remains on the floor below (5). Mating takes place in the autumn (2), but fertilisation is delayed until the following spring (6), as females store sperm inside their uterus (womb) during the winter hibernation (6). In April and May maternity roosts typically of 10-50 females form, and unlike many species of bats, males also occur in these roosts (2). A single young (rarely two) is produced around the middle of June (2). When the mother goes out to hunt, the young are left in a 'crèche'; they can fly after 3 weeks, and are independent at 6 weeks of age (5). The brown long-eared bat can live to a maximum of 22 years, but the more likely average life span is 4.5 years (2).

The brown long-eared bat is the second most common bat in Great Britain (5) after the pipistrelles (7). As the name suggests, it has exceptionally long ears that are almost as long as the body (5). When at rest, the ears are often tucked away under a wing or curled back like ram's horns, with just the long, delicate tragus visible (5). This medium-sized bat has broad wings, the long fluffy fur is grey-brown in colour, becoming yellowish in places, and the belly is a lighter grey (2). Juveniles are pale grey in colour, lacking the brown tinges of the adults (2).

Plecotus auritus is endemic to Europe, where it is widely distributed south of 65°N and west of the Urals and north of the Caucasus. In the south it is confined to higher elevations. It occurs on the British Isles and in Sardinia. Patchy distribution in Iberia, Italy and the Balkan Peninsula. In the Alps, maternity colonies are found up to 1,920 m asl, hibernacula up to 2,350 m asl (Horácek and Dulic 2004).

Plecotus auritus is found all across Eurasia, from Spain east to Japan, and south into India.

Biogeographic Regions: palearctic (Native )

Common and widespread (7) throughout Great Britain and Ireland, except for exposed islands (5). Elsewhere it is common and widespread across most of Europe with the exception of Greece, southern Italy and southern Spain (5).

As their common name implies, P. auritus have large ears--almost as long as their bodies. When in flight, the bats hold the ears fully erect and extended forward. At rest, their ears fold and curl sideways in a way that resembles ram horns. During hibernation the bats fold and tuck ears down, so that only the long pointed ear cover is visible.

P. auritus have relatively large eyes without a tapetum lucidum, and slit-shaped nostrils that open laterally. They usually weigh 6-12 grams and females are slightly larger than males. They have long, silky fur that is brownish on the upper side and grayish brown below. The dental formula for the P. auritus is 2/3, 1/1, 2/3, 3/3=36.

(Grzimek, 1975; Howard, 1995; Swift, 1998)

Range mass: 6 to 12 g.

Average mass: 8 g.

Other Physical Features: endothermic ; bilateral symmetry

Average basal metabolic rate: 0.082 W.

Habitat and Ecology

Systems

• Terrestrial

In general, P. auritus seem to prefer higher altitudes. In the summer, the long-eared bat can most often be found roosting in hollow trees at the edge of parks or woodlands. They are also commonly found clustering next to a chimney or along the beams of large roof spaces in stables, barns, lofts, and older buildings. From mid October to early April they hibernate in caves, mineshafts, hollow trees, under roofs, and in underground sites. Favorite roost sites of the long-eared bat can often be indicated by stains on the timbers.

Range elevation: 1,400 (high) m.

Habitat Regions: temperate ; terrestrial

Terrestrial Biomes: forest

Other Habitat Features: suburban

Found in open woodlands, both deciduous and coniferous, as well as parks and gardens (2). Summer roosts and maternity roosts occur in tree holes, bat boxes and attics (2), hibernation occurs in trees, hollow walls, caves, tunnels and mines (5).

P. auritus are insectivorous, feeding mainly on Lepidoptera (moths). They are opportunistic foragers, feeding on the most available insects, including beetles, flies, earwigs, and spiders. Long-eared bats forage in a variety of ways, such as catching insects in free flight, landing on the ground to capture prey, or hovering in mid-air to listen for movements of insects to pick them off the foliage. They forage at night, usually relatively close to their roost.

(Burton, 1962; Roberts and Hutson, 2001)

Animal Foods: insects; terrestrial non-insect arthropods

Primary Diet: carnivore (Insectivore )

P. auritus harbor relatively few parasites comparted to other bats, perhaps due to its small colony size. Several species of fleas in the family Ischnopsyllidae and mites in Spinturnicidae have been recorded on long-eared bats.

The only species of internal parasites that have been noted in P. auritus are bacteria in the genus Grahamella.

Mutualist Species:

• Grahamella (internal parasite)
• Ischnopsyllidae (Bat fleas)
• Spincturnidae (Mites) including:
• Spincturnix plecotina
• Ornithonussus pipistrelli
• Neomyobia plecotia
• Leptotrombidium russicum

Long-eared bats avoid most predators by only flying at night; however, they are still sometimes captured by some nocturnal predators such as owls and cats. The domestic cat is the most significant mammalian predator, especially to bats roosting under the roofs of houses. Their habit of flying close to the ground to forage and landing to catch insects makes them especially vulnerable to cats.

Known Predators:

• tawny owls (Strix aluco)
• barn owls (Tyto alba)
• long-eared owls (Asio otus)
• domestic cats (Felis silvestris)

Plecotus auritus is prey of:
Tyto alba
Asio otus
Felis silvestris
Strix aluco

This list may not be complete but is based on published studies.

Plecotus auritus preys on:
Arthropoda
Insecta

This list may not be complete but is based on published studies.

Animal / parasite / ectoparasite
Basilia nana ectoparasitises Plecotus auritus
Other: minor host/prey

Animal / parasite / ectoparasite
Nycteribia kolenatii ectoparasitises Plecotus auritus
Other: minor host/prey

In Great Britain and/or Ireland:
Animal / parasite / ectoparasite
Phthiridium biarticulata ectoparasitises Plecotus auritus
Other: minor host/prey

Climate is a very important factor for the survival of the young long-eared bat. Poor weather during lactation results in delayed growth, abandonment by mother and high mortality. Although records show that P. auritus are able to live up to thirty years, the average lifespan is seven years for males, sixteen years for females, and fifteen years for the sexes combined. High longevity could be due to the large amounts of time spent in a state of torpor, when the metabolic rate is very low.

Range lifespan

Status: wild: over 30 (high) years.

Average lifespan

Status: wild: 15 years.

Average lifespan

Status: wild: 12.0 years.

Maximum longevity: 30 years (wild)

Mating System: polygynandrous (promiscuous)

These bats and mate in autumn. For males, sperm production reaches its peak in late August and September, when the testes are descended. The testes regress and sperm production ceases in November. Females delay fertilization until spring (late April or May).

Females only bear one offspring per breeding season (every year); twins are very rare.

Breeding interval: once per year

Breeding season: Autumn

Range number of offspring: 1 to 3.

Average number of offspring: 1.

Range gestation period: 60 to 70 days.

Range weaning age: 40 to 45 days.

Average weaning age: 42 days.

Range age at sexual or reproductive maturity (female): 12 to 15 months.

Range age at sexual or reproductive maturity (male): 12 to 15 months.

Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); viviparous ; delayed implantation

Average number of offspring: 1.33.

The gestation period of Long-eared bats is relatively long, but the specifics are unknown. The young are altricial at birth, born pink and hairless with disproportionately large feet, used to grasp their mothers' fur once they are born. They feed on their mothers' milk until they are three weeks old, and then are left in the roost while the mother leaves to forage for food. At six weeks old they are weaned and able to forage for themselves. Females are often ready to breed at one year old and males are sexually mature at fifteen months.

(Roberts and Hutson, 2001; Swift, 1998)

Parental Investment: altricial ; female parental care

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 0
Species: 11
Species With Barcodes: 1

US Migratory Bird Act: no special status

US Federal List: no special status

CITES: no special status

IUCN Red List of Threatened Species: least concern

In Great Britain, all bats are fully protected under Schedule 5 of the Wildlife and Countryside Act (1981) as amended, and by the Conservation (Natural Habitats &c.) Regulations (1994). An agreement on the Conservation of Bats in Europe (EUROBATS) under the auspices of the Bonn Convention, also known as the Convention on Migratory species (CMS) is in force, and all European bats are listed under Appendix II of the CMS (4).

Population

Population Trend

Major Threats

Like all bats, this species is vulnerable to a number of threats, including the loss of roost sites; hollow trees are often felled if thought unsafe or 'untidy'. Habitat change and loss, affecting the availability of insect prey and causing the fragmentation of feeding habitat is a serious problem for many bats, furthermore pesticide use has devastating effects, by causing severe declines in insect prey abundance, and contaminating food with potentially fatal toxins (4). Insecticides applied to timbers inside buildings where roosts occur are a particular danger, the initial treatment can wipe out whole colonies (spraying timber where bats are roosting is now illegal), but the effects of these chemicals can be lethal to bats for up to 20 years (4).

Conservation Actions

In Britain, bats benefit from a very comprehensive level of legal protection (4). Under the Wildlife and Countryside Act it is illegal to intentionally kill, injure, take or sell a bat, posses a live bat or part of a bat, to intentionally, or in England and Wales, recklessly damage obstruct or destroy access to bat roosts. Under the Conservation Regulations it is an offence to damage or destroy breeding sites or resting places. Fines of up to £5,000 per bat affected and six months imprisonment are in place for these offences (3). Several species of bat also benefit by the public putting bat boxes up.

They consume large numbers of insect pests.

Positive Impacts: controls pest population