Greater horseshoe bat
|Greater horseshoe bat|
|Greater horseshoe bat range|
The greater horseshoe bat (Rhinolophus ferrumequinum) is a European bat of the Rhinolophus genus. Its distribution covers Europe, Africa, South Asia, China, Korea, Japan and Australia. It is the largest of the European horseshoe bats and is thus easily distinguished from other species. The species is sedentary, travelling between 20 and 30 km between the winter and summer roosts, with the longest recorded movement being 180 km. The species is notable as having the oldest recorded age for any European bat, with a bat living for over 30 years. The frequencies used by this bat species for echolocation lie between 69–83 kHz, have most energy at 81 kHz and have an average duration of 37.4 ms.
Its distinctive horseshoe noseleaf helps to focus the ultrasound it uses to 'see'.
The greater horseshoe bat is on average between 57 and 71 mm long, with a 35–43 mm tail and a 350–400 mm wingspan. The fur of the species is soft and fluffy, with the base of hairs being light grey, the dorsal side hair grey brown and the ventral side grey-white, with juvenile bats having more of an ash-grey tint to their fur. Wing membranes and ears are light grey-brown. It weighs up to 30 grams. During the winter the bats hibernate in caves, abandoned mines or other underground places.
The greater horseshoe bat lives in warmer regions of areas of open trees and scrub, near areas of standing water (e.g., ponds), areas of limestone and human settlement. The species is mainly house-dwelling in the north and cave-dwelling in the south. In the mountains nests are normally at below 800 metres above sea level. They are faithful to their summer and winter roosts, returning to the same sites each year.
Females normally produce their young when around 4 years old in England and 3 years old in the south of Europe, with males becoming mature around the end of their second year. Mating season is from autumn to spring, with nurseries of up to 200 females clustered together with their young. The maternity roosts are usually found in old buildings, occasionally caves or abandoned mines.
The babies are born in June or July. Each bat only has one baby. Young greater horseshoe bats open their eyes at about 4 days, are able to fly after three weeks and become independent at 7–8 weeks, during August. The false nipples of female bats, which newborn bats cling to after birth, are not fully developed until after the first birth.
Diet and hunting
The species feeds preferentially on lepidoptera (moths), making up around 41% of the diet by volume. – in particular the noctuidae species, Coleoptera (beetles) constitute around 33% of the diet, of which dung beetles are often taken Aphodius rufipes is one such dung beetle forming an especially important part of its diet. Cow pats are part of its life cycle, acting as food source and habitat for the larvae. Up to 100 larvae can be found in a single cow pat. The beetle is most abundant in August when the young bats begin their first feeeding flights). The remainder of the diet being hymenoptera and diptera. Cockchafers also form an important part of its diet.
The feeding area from the maternity roost is typically of radius 4 km, as neither the lactating females or young can travel far. In late August and September the bats feed on cranefly, to fatten up before hibernation. Breeding females depend on beetles from April until June, and moths from June to August.
The greater horseshoe bat leaves its roost at dusk, and its flying is made up of slow, fluttering travel with short glides, normally between 0.3 and 6 metres above the ground, with little hunting during wet and windy weather. It hunts in terrain with poor tree cover such as hillsides, cliff faces and in gardens, locating insects from its resting place and then intercepting them. The species has the ability to pick food up off the ground while still in flight, and indeed drinks during low-level flight or while hovering. The feeding range of colonies in England is between 8 and 16 kilometres.
Status in Britain
The species is rare in Britain, confined to just a small number of sites. Its distribution can be found on the National Biodivesity website here . Its breeding sites include Brockley Hall Stables near Bristol, Iford Manor near Bath, and Littledean Hall in the Forest of Dean. Its winter hibernation sites include Banwell Caves and Compton Martin Ochre Mine in the Mendip Hills, Chilmark Quarries in Wiltshire, and Combe Down and Bathampton Down Mines near Bath. In Dorset, the species roosts at Bryanston, Creech Grange and in Belle Vue Quarry. The species also occurs at Berry Head in Devon and has a monitored roost site at Woodchester Mansion in Stroud. In recent years the species has been found in several locations across the Home Counties and in Norfolk.
The species has disappeared from over half of its former range within the United Kingdom, with about 1% of the population surviving. Like all horseshoe bats it is sensitive to disturbance, and is threatened by the use of insecticides and the elimination of beetles by the changing agricultural practices.
There are seventeen recorded species of bat in Britain as of recent survey results.The greater horseshoe bat is one of the rarest. There are currently 35 recognised maternity and all-year roosts and 369 hibernation sites. Current estimates range between 4000 and 6600 individuals. Greater Horseshoes have declined for numerous reasons ranging from the use of agrichemicals (Ivermectin in particular) to loss of habitat and redundancy of farming methods. Avermectin kills off insect larvae and thus a decrease in the abundance of food for the Horseshoes, causing them to travel further and face increased dangers. Habitat loss is primarily the lack of established hedgerows and deciduous woodland-pasture ecotones. Modern farming methods have seen the reduction of cattle-grazing and this has impacted the Horseshoes who previously found that dung attracted insects and sustained entomogenous populations, giving their prey a stable population.
- Chiroptera Specialist Group (2000). "Rhinolophus ferrumequinum". IUCN Red List of Threatened Species. Version 3.1. International Union for Conservation of Nature. Retrieved 25 August 2012.
- Maurice Burton, Robert Burton (2002). The international wildlife encyclopedia, Volume 9 Marshall Cavendish, ISBN 0-7614-7266-5
- Bristol University page on Greater Horseshoe Bat. Bio.bris.ac.uk (2005-02-24). Retrieved on 2012-12-30.
- Parsons, S. and Jones, G. (2000). "Acoustic identification of twelve species of echolocating bat by discriminant function analysis and artificial neural networks". The Journal of experimental biology 203 (Pt 17): 2641–56. PMID 10934005.
- Obrist, M.K., Boesch, R. and Flückiger, P.F. (2004). "Variability in echolocation call design of 26 Swiss bat species: Consequences, limits and options for automated field identification with a synergetic pattern recognition approach". Mammalia 68 (4): 307. doi:10.1515/mamm.2004.030.
- Nature, English (1998). Managing Landscapes For The Greater Horseshoe Bat. Ruddocks (Lincoln) Ltd. ISBN 1-85716-416-4.
- Jones, G. (1990). "Prey selection by the greater horsehoe bat (Rhinolophus ferrumequinum): Optimal foraging by echolocation?". Journal of Animal Ecology 59 (2): 587–602. doi:10.2307/4882. JSTOR 4882.
- Bat Conservation Trust Greater Horseshoe bat Species information leaflet
- Wild Devon, The Magazine of the Devon Wildlife Trust, p. 14, Winter 2009
- Schober, Wilfried; Eckard Grimmberger (1989). Dr. Robert E. Stebbings, ed. A Guide to Bats of Britain and Europe (1st ed.). UK: Hamlyn Publishing Group. ISBN 0-600-56424-X.
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- Bristol University page on Greater Horseshoe Bat
- Woodland Management For Bats Guide
- Greater Horseshoe Bat protection project in South Tyrol – Italy