Horseshoe bats are bats in the family Rhinolophidae. In addition to the single living

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

, ''Rhinolophus'', which has about 106 species, the extinct genus '' Palaeonycteris'' has been recognized. Horseshoe bats are closely related to the Old World leaf-nosed bats, family Hipposideridae, which have sometimes been included in Rhinolophidae. The horseshoe bats are divided into six

subgenera In biology, a subgenus ( subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the ge ...

and many species groups. The most recent common ancestor of all horseshoe bats lived 34–40 million years ago, though it is unclear where the geographic roots of the family are, and attempts to determine its

biogeography Biogeography is the study of the species distribution, distribution of species and ecosystems in geography, geographic space and through evolutionary history of life, geological time. Organisms and biological community (ecology), communities o ...

have been indecisive. Their

taxonomy image:Hierarchical clustering diagram.png, 280px, Generalized scheme of taxonomy Taxonomy is a practice and science concerned with classification or categorization. Typically, there are two parts to it: the development of an underlying scheme o ...

is complex, as genetic evidence shows the likely existence of many

cryptic species In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

, as well as species recognized as distinct that may have little

genetic divergence Genetic divergence is the process in which two or more populations of an ancestral species accumulate independent genetic changes ( mutations) through time, often leading to reproductive isolation and continued mutation even after the populations h ...

from previously recognized taxa. They are found in the

Old World The "Old World" () is a term for Afro-Eurasia coined by Europeans after 1493, when they became aware of the existence of the Americas. It is used to contrast the continents of Africa, Europe, and Asia in the Eastern Hemisphere, previously ...

, mostly in tropical or

subtropical The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones immediately to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Ge ...

areas, including Africa, Asia, Europe, and Oceania. Horseshoe bats are considered small or medium-sized microbats, weighing , with forearm lengths of and combined lengths of head and body of . The fur, long and smooth in most species, can be reddish-brown, blackish, or bright orange-red. They get their common name from their large

nose-leaf A nose-leaf, or leaf nose, is an often large, lance-shaped nose, found in bats of the Phyllostomidae, Hipposideridae, and Rhinolophidae families. Because these bats Animal echolocation, echolocate nasally, this nose-leaf is thought to serve a role ...

s, which are shaped like horseshoes. The nose-leafs aid in echolocation; horseshoe bats have highly sophisticated echolocation, using constant frequency calls at high-

duty cycle A duty cycle or power cycle is the fraction of one period in which a signal or system is active. Duty cycle is commonly expressed as a percentage or a ratio. A period is the time it takes for a signal to complete an on-and-off cycle. As a for ...

s to detect prey in areas of high environmental clutters. They hunt insects and spiders, swooping down on prey from a perch, or gleaning from foliage. Little is known about their mating systems, but at least one species is monogamous, while another is polygynous.

Gestation Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during pregn ...

is approximately seven weeks and one offspring is produced at a time. A typical lifespan is six or seven years, but one

greater horseshoe bat The greater horseshoe bat (''Rhinolophus ferrumequinum'') is an Insectivore, insectivorous bat of the genus ''Rhinolophus''. Its distribution covers Europe, Northern Africa, Central Asia and Eastern Asia. It is the largest of the horseshoe bats i ...

lived more than thirty years. Horseshoe bats are relevant to humans in some regions as a source of disease, as food, and for

traditional medicine Traditional medicine (also known as indigenous medicine or folk medicine) refers to the knowledge, skills, and practices rooted in the cultural beliefs of various societies, especially Indigenous groups, used for maintaining health and treatin ...

. Several species are the natural reservoirs of various SARS-related coronaviruses, and data strongly suggests they are a reservoir of SARS-CoV, though humans may face more exposure risk from intermediate hosts such as

masked palm civet The masked palm civet (''Paguma larvata''), also called the gem-faced civet or Himalayan palm civet, is a viverrid species native to the Indian subcontinent and Southeast Asia. It has been listed as least concern on the IUCN Red List since 2008 ...

s. They are hunted for food in several regions, particularly

sub-Saharan Africa Sub-Saharan Africa is the area and regions of the continent of Africa that lie south of the Sahara. These include Central Africa, East Africa, Southern Africa, and West Africa. Geopolitically, in addition to the list of sovereign states and ...

, but also

Southeast Asia Southeast Asia is the geographical United Nations geoscheme for Asia#South-eastern Asia, southeastern region of Asia, consisting of the regions that are situated south of China, east of the Indian subcontinent, and northwest of the Mainland Au ...

. Some species or their

guano Guano (Spanish from ) is the accumulated excrement of seabirds or bats. Guano is a highly effective fertiliser due to the high content of nitrogen, phosphate, and potassium, all key nutrients essential for plant growth. Guano was also, to a le ...

are used in traditional medicine in Nepal, India, Vietnam, and Senegal.

Taxonomy and evolution

Taxonomic history

''Rhinolophus'' was first described as a genus in 1799 by French naturalist

Bernard Germain de Lacépède Bernard-Germain-Étienne de La Ville-sur-Illon, comte de Lacépède or La Cépède (; 26 December 17566 October 1825) was a French natural history, naturalist and an active freemason. He is known for his contribution to the Comte de Buffon's g ...

. Initially, all extant horseshoe bats were in ''Rhinolophus'', as well as the species now in '' Hipposideros'' (roundleaf bats). At first, ''Rhinolophus'' was within the family Vespertilionidae. In 1825, British zoologist

John Edward Gray John Edward Gray (12 February 1800 – 7 March 1875) was a British zoologist. He was the elder brother of zoologist George Robert Gray and son of the pharmacologist and botanist Samuel Frederick Gray (1766–1828). The same is used for a z ...

subdivided Vespertilionidae into subfamilies, including what he called Rhinolophina. English zoologist Thomas Bell is credited as the first to recognize horseshoe bats as a separate family, using Rhinolophidae in 1836. While Bell is sometimes recognized as the

authority Authority is commonly understood as the legitimate power of a person or group of other people. In a civil state, ''authority'' may be practiced by legislative, executive, and judicial branches of government,''The New Fontana Dictionary of M ...

for Rhinolophidae, the authority is more often given as Gray, 1825. Horseshoe bats are in the superfamily

Rhinolophoidea Rhinolophoidea is a superfamily (taxonomy), superfamily of bats. It contains the following families: Craseonycteridae, Hipposideridae, Megadermatidae, Rhinolophidae, Rhinonycteridae, and Rhinopomatidae. It is one of two superfamilies that compris ...

, along with Craseonycteridae,

Hipposideridae The Hipposideridae are a family (biology), family of bats commonly known as the Old World leaf-nosed bats. While it has often been seen as a subfamily, Hipposiderinae, of the family Rhinolophidae, it is now more generally classified as its own fa ...

Megadermatidae,

Rhinonycteridae Rhinonycteridae is a family of bats, within the suborder Yinpterochiroptera. The type species, the orange nose-leafed species group ''Rhinonicteris aurantia'', is found across the north of Australia. Description The family accords with the des ...

, and Rhinopomatidae. Attempts were made to divide ''Rhinolophus'' into other genera. In 1816, English zoologist

William Elford Leach William Elford Leach (2 February 1791 – 25 August 1836) was an English zoologist and marine biologist. Life and work Elford Leach was born at Hoe Gate, Plymouth, the son of an attorney. At the age of twelve he began a medical apprenticesh ...

proposed the genus name ''Phyllorhina''; Gray proposed ''Aquias'' in 1847 and ''Phyllotis'' in 1866; and German naturalist

Wilhelm Peters Wilhelm Karl Hartwich (or Hartwig) Peters (22 April 1815 – 20 April 1883) was a German natural history, naturalist and explorer. He was assistant to the anatomist Johannes Peter Müller and later became curator of the Natural History Museum, ...

proposed ''Coelophyllus'' in 1867. In 1876, Irish zoologist George Edward Dobson returned all Asiatic horseshoe bats to ''Rhinolophus'', additionally proposing the subfamilies Phyllorhininae (for the hipposiderids) and Rhinolophinae. American zoologist Gerrit Smith Miller Jr. further divided the hipposiderids from the horseshoe bats in 1907, recognizing Hipposideridae as a distinct family. Some authors have considered ''Hipposideros'' and associated genera as part of Rhinolophidae as recently as the early 2000s, though they are now most often recognized as a separate family. After the split into Rhinolophidae and Hipposideridae, further divisions were proposed for ''Rhinolophus'', with ''Rhinolphyllotis'' in 1934 and ''Rhinomegalophus'' in 1951, though both additional genera were returned to ''Rhinolophus''. Danish mammalogist Knud Andersen was the first to propose species groups for ''Rhinolophus'', doing so in 1905. Species groups are a way of clustering species to reflect evolutionary relationships. He recognized six species groups: ''R. simplex'' (now ''R. megaphyllus''), ''R. lepidus'', ''R. midas'' (now ''R. hipposideros''), ''R. philippinensis'', ''R. macrotis'', and ''R. arcuatus''. The species have been frequently rearranged among the groups as new groups are added, new species are described, and relationships among species are revised. Fifteen species groups were given by Csorba and colleagues in 2003. Various

have been proposed as well, with six listed by Csorba ''et al''. in 2003: ''Aquias'', ''Phyllorhina'', ''Rhinolophus'', ''Indorhinolophus'', ''Coelophyllus'', and ''Rhinophyllotis''. Informally, the rhinolophids can be split into two major

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

s: the mostly African clade, and the mostly

Orient The Orient is a term referring to the East in relation to Europe, traditionally comprising anything belonging to the Eastern world. It is the antonym of the term ''Occident'', which refers to the Western world. In English, it is largely a meto ...

al clade.

Evolutionary history

The most recent common ancestor of ''Rhinolophus'' lived an estimated 34–40 million years ago, splitting from the hipposiderid lineage during the

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

. Fossilized horseshoe bats are known from Europe (early to mid-

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

, early

Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

), Australia (Miocene), and Africa (Miocene and late

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58 The

of horseshoe bats is poorly understood. Various studies have proposed that the family originated in Europe, Asia, or Africa. A 2010 study supported an Asian or Oriental origin of the family, with rapid

evolutionary radiation An evolutionary radiation is an increase in taxonomic diversity that is caused by elevated rates of speciation, that may or may not be associated with an increase in morphological disparity. A significantly large and diverse radiation within ...

s of the African and Oriental clades during the Oligocene. A 2019 study found that '' R. xinanzhongguoensis'' and ''R. nippon'', both Eurasian species, are more closely related to African species than to other Eurasian species, suggesting that rhinolophids may have a complex biogeographical relationship with Asia and the

Afrotropics The Afrotropical realm is one of the Earth's eight biogeographic realms. It includes Sub-Saharan Africa, the southern Arabian Peninsula, the island of Madagascar, and the islands of the western Indian Ocean. It was formerly known as the Ethiopi ...

. A 2016 study using mitochondrial and

nuclear DNA Nuclear DNA (nDNA), or nuclear deoxyribonucleic acid, is the DNA contained within each cell nucleus of a eukaryotic organism. It encodes for the majority of the genome in eukaryotes, with mitochondrial DNA and plastid DNA coding for the rest. ...

placed the horseshoe bats within the

Yinpterochiroptera The Yinpterochiroptera (or Pteropodiformes) is a suborder of the Chiroptera, which includes taxa formerly known as megabats and five of the microbat families: Rhinopomatidae, Rhinolophidae, Hipposideridae, Craseonycteridae, and Megadermatidae. T ...

sister A sister is a woman or a girl who shares parents or a parent with another individual; a female sibling. The male counterpart is a brother. Although the term typically refers to a familial relationship, it is sometimes used endearingly to ref ...

to Hipposideridae. Rhinolophidae is represented by one extant genus, ''Rhinolophus''. Both the family and the genus are confirmed as

monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

(containing all descendants of a common ancestor). As of 2019, there were 106 described species in ''Rhinolophus'', making it the second-most speciose genus of bat after '' Myotis''. ''Rhinolophus'' may be undersampled in the Afrotropical realm, with one genetic study estimating that there could be up to twelve

in the region. Additionally, some taxa recognized as full species have been found to have little

. '' Rhinolophus kahuzi'' may be a

synonym A synonym is a word, morpheme, or phrase that means precisely or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are a ...

for the Ruwenzori horseshoe bat (''R. ruwenzorii''), and ''R. gorongosae'' or ''R. rhodesiae'' may be synonyms of the Bushveld horseshoe bat (''R. simulator''). Additionally, Smithers's horseshoe bat (''R. smithersi''), Cohen's horseshoe bat (''R. cohenae''), and the Mount Mabu horseshoe bat (''R. mabuensis'') all have little genetic divergence from Hildebrandt's horseshoe bat (''R. hildebrandtii''). Recognizing the former three as full species leaves Hildebrandt's horseshoe bat

paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

. The second genus in Rhinolophidae is the extinct '' Palaeonycteris'', with the type species ''Palaeonycteris robustus''. ''Palaeonycteris robustus'' lived during the Lower Miocene and its fossilized remains were found in Saint-Gérand-le-Puy, France.

Description

Appearance

Horseshoe bats are considered small or medium microbats. Individuals have a head and body length ranging and have forearm lengths of . One of the smaller species, the lesser horseshoe bat (''R. hipposideros''), weighs , while one of the larger species, the

(''R. ferrumequinum''), weighs . Fur color is highly variable among species, ranging from blackish to reddish brown to bright orange-red. The underparts are paler than the back fur. The majority of species have long, soft fur, but the woolly and lesser woolly horseshoe bats (''R. luctus'' and ''R. beddomei'') are unusual in their very long, woolly fur. Like most bats, horseshoe bats have two

mammary gland A mammary gland is an exocrine gland that produces milk in humans and other mammals. Mammals get their name from the Latin word ''mamma'', "breast". The mammary glands are arranged in organs such as the breasts in primates (for example, human ...

s on their chests. Adult females additionally have two teat-like projections on their abdomens, called pubic nipples or false nipples, which are not connected to mammary glands. Only a few other bat families have pubic nipples, including Hipposideridae, Craseonycteridae, Megadermatidae, and Rhinopomatidae; they serve as attachment points for their offspring. In a few horseshoe bat species, males have a false nipple in each armpit.

Head and teeth

All horseshoe bats have large, leaf-like protuberances on their noses, which are called

s. The nose-leafs are important in species identification, and are composed of several parts. The front of the nose-leaf resembles and is called a

horseshoe A horseshoe is a product designed to protect a horse hoof from wear. Shoes are attached on the palmar surface (ground side) of the hooves, usually nailed through the insensitive hoof wall that is anatomically akin to the human toenail, altho ...

, earning them the common name of "horseshoe bats". The horseshoe is above the upper lip and is thin and flat. The lancet is triangular, pointed, and pocketed, and points up between the bats' eyes. The sella is a flat, ridge-like structure at the center of the nose. It rises from behind the nostrils and points out perpendicular from the head. Their ears are large and leaf-shaped, nearly as broad as they are long, and lack tragi. The antitragi of the ears are conspicuous. Their eyes are very small. The skull always has a rostral inflation, or bony protrusion on the snout. The typical dental formula of a horseshoe bat is , but the middle lower premolars are often missing, as well as the anterior upper premolars (premolars towards the front of the mouth). The young lose their milk teeth while still in utero, with the teeth resorbed into the body. They are born with the four permanent canine teeth erupted, which enables them to cling to their mothers. This is atypical among bat families, as most newborns have at least some milk teeth at birth, which are quickly replaced by the permanent set.

Postcrania

Several bones in its

thorax The thorax (: thoraces or thoraxes) or chest is a part of the anatomy of mammals and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main di ...

are fused—the presternum, first

rib In vertebrate anatomy, ribs () are the long curved bones which form the rib cage, part of the axial skeleton. In most tetrapods, ribs surround the thoracic cavity, enabling the lungs to expand and thus facilitate breathing by expanding the ...

, partial second rib, seventh cervical vertebra, first

thoracic vertebra In vertebrates, thoracic vertebrae compose the middle segment of the vertebral column, between the cervical vertebrae and the lumbar vertebrae. In humans, there are twelve thoracic vertebra (anatomy), vertebrae of intermediate size between the ce ...

—making a solid ring. This fusion is associated with the ability to echolocate while stationary. Except for the first digit, which has two

phalanges The phalanges (: phalanx ) are digit (anatomy), digital bones in the hands and foot, feet of most vertebrates. In primates, the Thumb, thumbs and Hallux, big toes have two phalanges while the other Digit (anatomy), digits have three phalanges. ...

, all of their toes have three phalanges. This distinguishes them from hipposiderids, which have two phalanges in all toes. The tail is completely enclosed in the uropatagium (tail membrane), and the trailing edge of the uropatagium has calcars ( cartilaginous spurs).

Biology and ecology

Echolocation and hearing

Horeshoe bats have very small eyes and their field of vision is limited by their large nose-leafs; thus, vision is unlikely to be a very important sense. Instead, they use echolocation to navigate, employing some of the most sophisticated echolocation of any bat group. To echolocate, they produce sound through their nostrils. While some bats use frequency-modulated echolocation, horseshoe bats use constant-frequency echolocation (also known as single-frequency echolocation). They have high

s, meaning that when individuals are calling, they are producing sound more than 30% of the time. The use of high duty, constant-frequency echolocation aids in distinguishing prey items based on size. These echolocation characteristics are typical of bats that search for moving prey items in cluttered environments full of foliage. They echolocate at particularly high frequencies for bats, though not as high as hipposiderids relative to their body sizes, and the majority concentrate most of the echolocation energy into the second harmonic. The king horseshoe bat (''R. rex'') and the large-eared horseshoe bat (''R. philippensis'') are examples of outlier species that concentrate energy into the first harmonic rather than the second. Their highly furrowed nose-leafs likely assist in focusing the emission of sound, reducing the effect of environmental clutter. The nose-leaf in general acts like a

parabolic reflector A parabolic (or paraboloid or paraboloidal) reflector (or dish or mirror) is a Mirror, reflective surface used to collect or project energy such as light, sound, or radio waves. Its shape is part of a circular paraboloid, that is, the surface ge ...

, aiming the produced sound while simultaneously shielding the ear from some of it. Horseshoe bats have sophisticated senses of hearing due to their well-developed

cochlea The cochlea is the part of the inner ear involved in hearing. It is a spiral-shaped cavity in the bony labyrinth, in humans making 2.75 turns around its axis, the modiolus (cochlea), modiolus. A core component of the cochlea is the organ of Cort ...

, and are able to detect Doppler-shifted echoes. This allows them to produce and receive sounds simultaneously. Within horseshoe bats, there is a negative relationship between ear length and echolocation frequency: Species with higher echolocation frequencies tend to have shorter ear lengths. During echolocation, the ears can move independently of each other in a "flickering" motion characteristic of the family, while the head simultaneously moves up and down or side to side.

Diet and foraging

Horseshoe bats are insectivorous, though consume other arthropods such as

spider Spiders (order (biology), order Araneae) are air-breathing arthropods that have eight limbs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude spider silk, silk. They are the largest order of arachnids and ran ...

s, and employ two main foraging strategies. The first strategy is flying slow and low over the ground, hunting among trees and bushes. Some species who use this strategy are able to hover over prey and glean them from the substrate. The other strategy is known as perch feeding: Individuals roost on feeding perches and wait for prey to fly past, then fly out to capture it. Foraging usually occurs above the ground. While

vesper bat Vespertilionidae is a family of microbats, of the order Chiroptera, flying, insect-eating mammals variously described as the common, vesper, or simple nosed bats. The vespertilionid family is the most diverse and widely distributed of bat famili ...

s may catch prey in their uropatagia and transfer it to their mouths, horseshoe bats do not use their uropatagia to catch prey. At least one species, the greater horseshoe bat, has been documented catching prey in the tip of its wing by bending the phalanges around it, then transferring it to its mouth. While a majority of horseshoe bats are nocturnal and hunt at night, Blyth's horseshoe bat (''R. lepidus'') is known to forage during the daytime on Tioman Island. This is hypothesized as a response to a lack of diurnal avian (day-active bird) predators on the island. They have especially small and rounded wingtips, low

wing loading In aerodynamics, wing loading is the total weight of an aircraft or flying animal divided by the area of its wing. The stalling speed, takeoff speed and landing speed of an aircraft are partly determined by its wing loading. The faster an airc ...

(meaning they have large wings relative to body mass), and high camber. These factors give them increased agility, and they are capable of making quick, tight turns at slow speeds. Relative to all bats, horseshoe bat wingspans are typical for their body sizes, and their aspect ratios, which relate wingspan to wing area, are average or lower than average. Some species, like Rüppell's horseshoe bat (''R. fumigatus''), Hildebrandt's horseshoe bat, Lander's horseshoe bat (''R. landeri''), and Swinny's horseshoe bat (''R. swinnyi''), have particularly large total wing area, though most horseshoe bat species have average wing area.

Reproduction and life cycle

The mating systems of horseshoe bats are poorly understood. A review in 2000 noted that only about 4% of species had published information about their mating systems; along with the

free-tailed bat The Molossidae, or free-tailed bats, are a family of bats within the order Chiroptera. The Molossidae is the fourth-largest family of bats, containing about 110 species as of 2012. They are generally quite robust, and consist of many strong-fly ...

s (Molossidae), they had received the least attention of any bat family relative to their species diversity. At least one species, the greater horseshoe bat, appears to have a polygynous mating system where males attempt to establish and defend territories, attracting multiple females. '' Rhinolophus sedulus'', however, is among the few species of bat that are believed to be

monogamous Monogamy ( ) is a relationship of two individuals in which they form a mutual and exclusive intimate partnership. Having only one partner at any one time, whether for life or serial monogamy, contrasts with various forms of non-monogamy (e.g. ...

(only 17 bat species are recognized as such as of 2000). Some species, particularly

temperate In geography, the temperate climates of Earth occur in the middle latitudes (approximately 23.5° to 66.5° N/S of the Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ran ...

species, have an annual breeding season in the fall, while other species mate in the spring. Many horseshoe bat species have the adaptation of delayed fertilization through

female sperm storage Female sperm storage is a biological process and often a type of sexual selection in which spermatozoa, sperm cells transferred to a female during mating are temporarily retained within a specific part of the reproductive tract before the oocyte, ...

. This is especially common in temperate species. In hibernating species, the sperm storage timing coincides with hibernation. Other species like Lander's horseshoe bat have

embryonic diapause Embryonic diapause (delayed implantation in mammals) is a reproductive strategy used by a number of animal species across different biological classes. In more than 130 types of mammals where this takes place, the process occurs at the blastocys ...

, meaning that while fertilization occurs directly following copulation, the

zygote A zygote (; , ) is a eukaryote, eukaryotic cell (biology), cell formed by a fertilization event between two gametes. The zygote's genome is a combination of the DNA in each gamete, and contains all of the genetic information of a new individ ...

does not implant into the uterine wall for an extended period of time. The greater horseshoe bat has the adaptation of delayed

embryo An embryo ( ) is the initial stage of development for a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sp ...

nic development, meaning that growth of the embryo is conditionally delayed if the female enters

torpor Torpor is a state of decreased physiological activity in an animal, usually marked by a reduced body temperature and metabolic rate. Torpor enables animals to survive periods of reduced food availability. The term "torpor" can refer to the ti ...

. This causes the interval between fertilization and birth to vary between two and three months. Gestation takes approximately seven weeks before a single offspring is born, called a pup. Individuals reach sexual maturity by age two. While lifespans typically do not exceed six or seven years, some individuals may have extraordinarily long lives. A greater horseshoe bat individual was once banded and then rediscovered thirty years later.

Behavior and social systems

Various levels of

sociality Sociality is the degree to which individuals in an animal population tend to associate in social groups (gregariousness) and form cooperative societies. Sociality is a survival response to evolutionary pressures. For example, when a mother ...

are seen in horseshoe bats. Some species are solitary, with individuals roosting alone, while others are highly colonial, forming aggregations of thousands of individuals. The majority of species are moderately social. In some species, the sexes segregate annually when females form maternity colonies, though the sexes remain together all year in others. Individuals hunt solitarily. Because their hind limbs are poorly developed, they cannot scuttle on flat surfaces nor climb adeptly like other bats. Horseshoe bats enter

to conserve energy. During torpor, their body temperature drops to as low as and their metabolic rates slow. Torpor is employed by horseshoe bats in temperate, sub-tropical, and tropical regions. Torpor has a short duration; when torpor is employed consistently for days, weeks, or months, it is known as hibernation. Hibernation is used by horseshoe bats in temperate regions during the winter months.

Predators and parasites

Overall, bats have few natural predators. Horseshoe bat predators include birds in the order Accipitriformes (hawks, eagles, and kites), as well as falcons and owls. Snakes may also prey on some species while they roost in caves, and domestic cats may hunt them as well. A 2019 study near a colony of bats in central Italy found that 30% of examined cat

feces Feces (also known as faeces American and British English spelling differences#ae and oe, or fæces; : faex) are the solid or semi-solid remains of food that was not digested in the small intestine, and has been broken down by bacteria in the ...

contained the remains of greater horseshoe bats. Horseshoe bats have a variety of internal and external

parasite Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted str ...

s. External parasites (ectoparasites) include

mite Mites are small arachnids (eight-legged arthropods) of two large orders, the Acariformes and the Parasitiformes, which were historically grouped together in the subclass Acari. However, most recent genetic analyses do not recover the two as eac ...

s in the genus '' Eyndhovenia'', "bat flies" of the families Streblidae and Nycteribiidae,

tick Ticks are parasitic arachnids of the order Ixodida. They are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, and species, but can become larger when engorged. Ticks a ...

s of the genus '' Ixodes'', and

flea Flea, the common name for the order (biology), order Siphonaptera, includes 2,500 species of small flightless insects that live as external parasites of mammals and birds. Fleas live by hematophagy, ingesting the blood of their hosts. Adult f ...

s of the genus '' Rhinolophopsylla''. They are also affected by a variety of internal parasites (endoparasites), including

trematode Trematoda is a Class (biology), class of flatworms known as trematodes, and commonly as flukes. They are obligate parasite, obligate Endoparasites, internal parasites with a complex biological life cycle, life cycle requiring at least two Host ( ...

s of the genera '' Lecithodendrium'', '' Plagiorchis'', '' Prosthodendrium'', and

cestode Cestoda is a class of parasitic worms in the flatworm phylum (Platyhelminthes). Most of the species—and the best-known—are those in the subclass Eucestoda; they are ribbon-like worms as adults, commonly known as tapeworms. Their bodies co ...

s of the genus '' Potorolepsis''.

Range and habitat

Horseshoe bats have a mostly Paleotropical distribution, though some species are in the southern

Palearctic realm The Palearctic or Palaearctic is a biogeographic realm of the Earth, the largest of eight. Confined almost entirely to the Eastern Hemisphere, it stretches across Europe and Asia, north of the foothills of the Himalayas, and North Africa. The ...

. They are found in the

, including Africa, Australia, Asia, Europe, and Oceania. The greater horseshoe bat has the greatest geographic range of any horseshoe bat, occurring across Europe, North Africa, Japan, China, and southern Asia. Other species are much more restricted, like the Andaman horseshoe bat (''R. cognatus''), which is only found on the

Andaman Islands The Andaman Islands () are an archipelago, made up of 200 islands, in the northeastern Indian Ocean about southwest off the coasts of Myanmar's Ayeyarwady Region. Together with the Nicobar Islands to their south, the Andamans serve as a mari ...

. They roost in a variety of places, including buildings, caves, tree hollows, and foliage. They occur in both forested and unforested habitat, with the majority of species occurring in tropical or subtropical areas. For the species that hibernate, they select caves with an ambient temperature of approximately .

Relationship to humans

As disease reservoirs

Coronaviruses

Horseshoe bats are of particular interest to public health and

zoonosis A zoonosis (; plural zoonoses) or zoonotic disease is an infectious disease of humans caused by a pathogen (an infectious agent, such as a virus, bacterium, parasite, fungi, or prion) that can jump from a non-human vertebrate to a human. When ...

as a source of

coronavirus Coronaviruses are a group of related RNA viruses that cause diseases in mammals and birds. In humans and birds, they cause respiratory tract infections that can range from mild to lethal. Mild illnesses in humans include some cases of the comm ...

es. Following the 2002–2004 SARS outbreak, several animal species were examined as possible

natural reservoir In Infection, infectious disease ecology and epidemiology, a natural reservoir, also known as a disease reservoir or a reservoir of infection, is the population of organisms or the specific environment in which an infectious pathogen naturally li ...

s of the causative coronavirus, SARS-CoV. From 2003 to 2018, forty-seven SARS-related coronaviruses were detected in horseshoe bats. In 2019, a wet market in

Wuhan Wuhan; is the capital of Hubei, China. With a population of over eleven million, it is the most populous city in Hubei and the List of cities in China by population, eighth-most-populous city in China. It is also one of the nine National cent ...

, China, was linked to the outbreak of

SARS-CoV-2 Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) is a strain of coronavirus that causes COVID-19, the respiratory illness responsible for the COVID-19 pandemic. The virus previously had the Novel coronavirus, provisional nam ...

. Genetic analyses of SARS-CoV-2 showed that it was highly similar to viruses found in horseshoe bats. After the SARS outbreak, the least horseshoe bat (''R. pusillus'') was seropositive, the greater horseshoe bat tested positive for the virus only, and the big-eared horseshoe bat (''R. macrotis''), Chinese rufous horseshoe bat (''R. sinicus''), and Pearson's horseshoe bat (''R. pearsoni'') were both seropositive ''and'' tested positive for the virus. The bats' viruses were highly similar to SARS-CoV, with 88–92% similarity. Intraspecies diversity of

SARS Severe acute respiratory syndrome (SARS) is a viral respiratory disease of zoonotic origin caused by the virus SARS-CoV-1, the first identified strain of the SARS-related coronavirus. The first known cases occurred in November 2002, and the ...

-like coronaviruses appears to have arisen in ''Rhinolophus sinicus'' by

homologous recombination Homologous recombination is a type of genetic recombination in which genetic information is exchanged between two similar or identical molecules of double-stranded or single-stranded nucleic acids (usually DNA as in Cell (biology), cellular organi ...

. ''R. sinicus'' likely harbored the direct ancestor of SARS-CoV in humans. Though horseshoe bats appeared to be the natural reservoir of SARS-related coronaviruses, humans likely became sick through contact with infected

s, which were identified as intermediate hosts of the virus. During the period from 2003 to 2018, forty-seven SARS-related coronaviruses were detected in bats, forty-five in horseshoe bats. Thirty SARS-related coronaviruses were from Chinese rufous horseshoe bats, nine from greater horseshoe bats, two from big-eared horseshoe bats, two from the least horseshoe bat, and one each from the intermediate horseshoe bat (''R. affinis''), Blasius's horseshoe bat (''R. blasii''), Stoliczka's trident bat (''Aselliscus stoliczkanus''), and the wrinkle-lipped free-tailed bat (''Chaerephon plicata''). In the market in Wuhan where the SARS-CoV-2 was detected, 96% had a similarity to a virus isolated from the intermediate horseshoe bat. Research on the evolutionary origins of SARS-CoV-2 indicates that bats were the natural reservoirs of SARS-CoV-2. It is yet unclear how the virus was transmitted to humans, though an intermediate host may have been involved. It was once believed to be the Sunda pangolin, but a July 2020 publication found no evidence of transmission from pangolins to humans.

Other viruses

They are also associated with viruses like orthoreoviruses, flaviviruses, and

hantavirus ''Orthohantavirus'' is a genus of viruses that includes all hantaviruses (family ''Hantaviridae'') that cause disease in humans. Orthohantaviruses, hereafter referred to as hantaviruses, are naturally found primarily in rodents. In general, each ...

es. They have tested positive for '' Mammalian orthoreovirus'' (MRV), including a type 1 MRV isolated from the lesser horseshoe bat and a type 2 MRV isolated from the least horseshoe bat. The specific MRVs found in horseshoe bats have not been linked to human infection, though humans can become ill through exposure to other MRVs. The rufous horseshoe bat (''R. rouxii'') has tested seropositive for Kyasanur Forest disease, which is a tick-borne viral hemorrhagic fever known from southern India. Kyasanur Forest disease is transmitted to humans through the bite of infected ticks, and has a mortality rate of 2–10%. Longquan virus, a kind of hantavirus, has been detected in the intermediate horseshoe bat, Chinese rufous horseshoe bat, and the little Japanese horseshoe bat (''R. cornutus'').

As food and medicine

Microbats are not hunted nearly as intensely as

megabat Megabats constitute the Family (biology), family Pteropodidae of the Order (biology), order Chiroptera. They are also called fruit bats, Old World fruit bats, or—especially the genus, genera ''Acerodon'' and ''Pteropus''—Pteropus, flyin ...

s: only 8% of insectivorous species are hunted for food, compared to half of all megabat species in the Old World tropics. Horseshoe bats are hunted for food, particularly in

. Species hunted in Africa include the halcyon horseshoe bat (''R. alcyone''), Guinean horseshoe bat (''R. guineensis''), Hill's horseshoe bat (''R. hilli''), Hills' horseshoe bat (''R. hillorum''), Maclaud's horseshoe bat (''R. maclaudi''), the Ruwenzori horseshoe bat, the forest horseshoe bat (''R. silvestris''), and the Ziama horseshoe bat (''R. ziama''). In Southeast Asia, Marshall's horseshoe bat (''R. marshalli'') is consumed in Myanmar and the

large rufous horseshoe bat The large rufous horseshoe bat (''Rhinolophus rufus'') is a species of bat in the family Rhinolophidae. It is endemic to the Philippines. References

Rhinolophidae Bats of Southeast Asia Bats of the Philippines Endemic fauna of the Phil ...

(''R. rufus'') is consumed in the Philippines. The

Ao Naga The Aos are a major Naga ethnic group native to Mokokchung District of Nagaland in Northeast India. Their main territory is from Tsüla (Dikhu) Valley in the east to Tsürang (Disai) Valley in the west in Mokokchung District. The Ao Nagas r ...

people of Northeast India are reported to use the flesh of horseshoe bats to treat

asthma Asthma is a common long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wh ...

. Ecological anthropologist Will Tuladhar-Douglas stated that the

Newar people Newar (; , endonym: Newa; , Pracalit script: ), or Nepami, are primarily inhabitants in Kathmandu Valley of Nepal and its surrounding areas, and the creators of its historic heritage and civilisation. Page 15. Newars are a distinct linguistic ...

of Nepal "almost certainly" use horseshoe bats, among other species, to prepare ''Cikā Lāpa Wasa'' ("bat oil"). Dead bats are rolled up and placed in tightly sealed jars of

mustard oil Mustard oil can mean either the pressed oil used for cooking or a pungent essential oil, also known as volatile oil, of the mustard plant. The essential oil results from grinding mustard seed, mixing the grounds with water, and isolating the resu ...

; the oil is ready when it gives off a distinct and unpleasant smell. Traditional medicinal uses of the bat oil include removing "earbugs", reported to be millipedes that crawl into one's ears and gnaw at the brain, possibly a traditional explanation of

migraine Migraine (, ) is a complex neurological disorder characterized by episodes of moderate-to-severe headache, most often unilateral and generally associated with nausea, and light and sound sensitivity. Other characterizing symptoms may includ ...

s. It is also used as a purported treatment for baldness and partial paralysis. In Senegal, there are anecdotal reports of horseshoe bats being used in potions to treat mental illness; in Vietnam, a pharmaceutical company reported using of horseshoe bat

each year for medicinal uses.

Conservation

As of 2023, the

IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...

had evaluated 94 species of horseshoe bat. They have the following IUCN statuses: *

Critically endangered An IUCN Red List critically endangered (CR or sometimes CE) species is one that has been categorized by the International Union for Conservation of Nature as facing an extremely high risk of extinction in the wild. As of December 2023, of t ...

: 1 species ( Hill's horseshoe bat) *

Endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...

: 13 species * Vulnerable: 5 species *

Near threatened A near-threatened species is a species which has been Conservation status, categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature (IUCN) as that may be vulnerable to Endangered species, endangerment in the ne ...

: 9 species *

Least concern A least-concern species is a species that has been evaluated and categorized by the International Union for Conservation of Nature (IUCN) as not being a focus of wildlife conservation because the specific species is still plentiful in the wil ...

: 51 species * Data deficient: 15 species Like all cave-roosting bats, cave-roosting horseshoe bats are vulnerable to disturbance of their cave habitats. Disturbance can include mining bat guano, quarrying

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

, and cave

tourism Tourism is travel for pleasure, and the Commerce, commercial activity of providing and supporting such travel. World Tourism Organization, UN Tourism defines tourism more generally, in terms which go "beyond the common perception of tourism as ...

References

{{Authority control it:Rhinolophidae