Lesser Horseshoe Bat

Lesser horseshoe bat, Rhinolophus hipposideros

Morphological Description Life History Distribution Habitat Roost Sites and Roosting Patterns Emergence and Flight Pattern Foraging Behaviour Echolocation Calls Status and Protection
Morphological Description Dorsal fur is pale greyish-brown. Ventral fur is pale grey. Juveniles are darker grey. Fur is long and fluffy. Is easily identified by a horseshoe-shaped flap of skin surrounding the nostrils. Can be distinguished from the greater horseshoe bat by size. The forearm of the lesser horseshoe bat is shorter than 45mm. Average weight (as given by Greenaway & Hutson, 1990) 5-9 g. The diagram below gives important average body measurements for lesser horseshoe bats (Greenaway & Hutson, 1990).
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Life History A single young is born between June and July (Ransome, 1991b). Maximum age recorded in Europe is 21 years but on average lesser horseshoe bats only live four years (Schober & Grimmberger, 1989). Back to top
Distribution

The British and World distributions are shown by the white areas of the maps above (as given by Richardson, 2000 and Corbet & Harris, 1991 respectively).
• Rare, localised populations occur in south west England, Wales and western Ireland. Back to top
Habitat
Back to top	• Sheltered valleys, woodland edge, pasture and wetlands. • Loss of foraging habitat may be responsible for the decline in lesser horseshoe bat populations in Europe. A study on lesser horseshoe bats in Monmouthshire, UK, showed that they mainly foraged in broadleaf woodlands, as well as in other woodlands and areas of high habitat diversity (Bontadina et al., 2002). As a result of these findings, Bontadina et al. emphasise the importance of conserving such habitats if they occur within 2.5km of a lesser horseshoe bat nursery roost. Motte and Libois (2002) found similar results from a study in Belgium and recommend the conservation of woodlands and hedgerows within 1-2km of lesser horseshoe bat roosts. • The photograph on the left shows a typical habitat of lesser horseshoe bats.
Roost Sites and Patterns
Summer roosts: In Europe nursery roosts are found from April through to October (Schober & Grimmberger, 1989) . Nursery roosts usually contain 30-70 females but sometimes as many as 200 may be present (Greenaway & Hutson, 1990). Females frequently change their roost site during the summer. Show a preference for roosts which can be accessed by interrupted flight. Roost in warm buildings (attics, boiler rooms etc.) and cave-like environments. Hang freely by the feet singly in warm sites with abundant food or in clusters of up to 150 in colder roosts (Ransome, 1991b). Hang with the wings wrapped around the body. Winter roosts: Hibernate from October through to April, active during the day in the hibernacula in spring and autumn. (Greenaway & Hutson, 1990; Ransome, 1991b). Roost in caves and similar environments, hanging freely high above the ground, occasionally found in lower crevices. Groups may be found close together but clusters do not occur. McAney (1994) suggests that the decline in Ireland 's populations of lesser horseshoe bats may be due to the loss of roost sites as well as the loss of foraging habitat and a series of cold winters. Back to top
Emergence and Flight Pattern
Emerges late after sunset and returns returns to the roost close to sunrise (Ransome, 1991b). Median emergence time is 31 minutes after sunset (Jones & Rydell, 1994). Flight is fast and agile. Flight is low, up to 5m above the ground (Russ, 1999). Hunting flight is slower and initially follows a regular path before the bat moves into vegetation. Back to top
Foraging Behaviour
• Forages close to dense vegetation in pasture, woodland and water environments. • Often uses temporary night feeding perches to eat larger prey. • The diet of lesser horseshoe bats mainly consists of Diptera, particularly the suborder Nematocera. Nematocerans are generally crepuscular and the males often swarm (Vaughan, 1997). Lesser horseshoe bats forage using hawking and gleaning strategies. Perch-hunting may also be used.

Marked in blue on the diagram above is a typical foraging path of lesser horseshoe bats (based on Russ, 1999). Back to top
Echolocation Calls
	The echolocation call of lesser horseshoe bats is constant frequency with a frequency modulated component at the start and end.
	To listen to the call of the lesser horseshoe bat click here Size of sound file: 86.5 KB
	For details of how the echolocation calls were recorded click here.
	Average values for a lesser horseshoe bat echolocation call, as given by Vaughan et al. (1997), are listed below: Interpulse interval: 79.9ms Call duration: 40.3ms Minimum frequency: 98.6kHz The power spectrum on the left shows that the maximum power of the call is at a frequency of approximately 100 kHz. Lesser horseshoe bats have a constant-frequency (CF) component to their calls. Male bats have a lower frequency CF component than females. Bats less than a year old have a lower frequency CF component than older bats (Jones et al., 1992).
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Status and Protection • The British pre-breeding population was estimated at 14,000 in 1995 (7000 in England, 7000 in Wales ) (Harris et al., 1995). • Lesser horseshoe bats have become extinct in the last 50 years in the north midlands and northern England (Schober & Grimmberger, 1989) . • The worldwide IUCN status (2001) for lesser horseshoe bats is Vulnerable. • Recent data indicate that the lesser horseshoe population may be increasing (Bat Conservation Trust 2001; Warren & Witter 2002). • Summer and winter roost sites need to be protected. Potential roost entrances should be left unobstructed. • Warren and Witter (2002) found that lesser horseshoe bat populations in Wales appeared to be stable from 1993-1997. They estimated the total Welsh population to be in excess of 10,000 individuals. Lesser horseshoe bat roost sites in Britain are currently conserved as part of conservation management schemes. The results of this study show that current conservation measures are adequate to maintain lesser horseshoe bat populations in Wales . Warren and Witter (2002) suggest that the number of lesser horseshoe bats in Wales might be increased by protecting potential roost sites, such as old buildings, and protecting and improving hibernacula and foraging habitats. Back to top
© School of Biological Sciences, University of Bristol 2005. Last modified 24th February 2005.