the molossidae , or free-tailed bats , are a family of bats within the order chiroptera .

they are generally quite robust , and consist of many strong flying forms with relatively long and narrow wings .

another common name for some members of this group , and indeed a few species from other families , is mastiff bat .

the western mastiff bat ( eumops perotis ) , a large species from the southwestern united states and mexico with wings over 0.5 m ( 1.6 ft ) across , is perhaps one of the best known with this name .

they are widespread , being found on every continent except antarctica .

the family 's scientific name comes from the type genus molossus , which in turn is from the molossus breed of dog .

the family 's common name is derived from a length of " free " tail , projecting beyond the end of the uropatagium – the membrane that connects the base of the tail to the hind legs .

the tail is usually best seen when resting .

a special ring of cartilage slides up or down the tail vertebrae by muscular action to stretch or retract the tail membrane .

this gives many species a degree of fine tuning in their flight maneuvers to rival their day-flying ecological equivalents , such as swifts , swallows , and martins .

as a result , these animals include the fastest-flying of all bat species among their number .

the dental formula of free-tailed bats varies between species : free-tailed bats are usually grey , brown , or black in color , with some exceptions .

they range from 4 to 12 cm ( 1.6 to 4.7 in ) in length , excluding the tail , and can weigh from 8 to 220 g ( 0.28 to 7.76 oz ) , depending on species .

they are insectivorous , and catch their food on the wing .

while some species roost in small groups in hollow trees or rocky crevices , some cave-dwelling species form vast colonies of up to 50 million individuals .

molecular sequence data supports the monophyly of molossidae as a whole , but not that of many of its genera , such as chaerephon , mops , mormopterus and tadarida .

the grouping of chaerephon minus c. jobimena plus mops was found to be monophyletic , as was otomops .

free - tailed bat

the mexican free - tailed bat ( tadarida brasiliensis ) is also known as the brazilian free - tailed bat . it is one of the most abundant free - tailed bats in the world and one of the most abundant mammals in north america . in places like south texas , the free - tailed bat roosts in large colonies during the summer months .
tracy barbaro changed the thumbnail image of
mexican free - tailed bat ( tadarida brasiliensis )
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mexican free - tailed bats are the
jets
of the bat world . they are very fast flyers .
refer to the online version of the mammals of texas for additional details on the brazilian free - tailed bat .
brazilian free - tailed bat order chiroptera : family molossidae : tadarida brasiliensis ( i . goef . st . - hilaire )
like others of their genus , mexican free - tailed bats have prominent wrinkled lips .
the brazilian free - tailed bat is a medium - sized bat with broad ears , large feet , and the end of its tail free . they have short , velvety , reddish to black - colored fur . for more information , see
another colonial bat ( myotis velifer ) is a common associate of the brazilian free - tailed bat in the guano caves . this bat also gives birth to its young in the guano caves , but at a time about 2 weeks in advance of the brazilian free - tailed bats . while the two kinds of bats tend to roost in separate clusters , some mixing may occur .
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the brazilian free - tailed bat is classified as least concern ( lc ) on the iucn red list ( 1 ) and is listed on appendix i of the convention on migratory species ( 4 ) .
this bat is a known carrier of rabies . although the proportion of rabies cases caused by brazilian free - tailed bats is minuscule when compared to the size of their population as a whole , caution should be exercised when one of these bats is encountered , or any species of bat for that matter .
although perhaps no species’ fate should be judged solely on its importance to humans , the brazilian free - tailed bat is known to have an enormous impact on insect numbers , thereby contributing to both the ecology and economy of those countries that are home to it . it is crucial to continue to protect its roost sites and to educate the public and the media as to the reality of rabies and the benefits of the brazilian free - tailed bat ( 7 ) .
with their long , narrow wings , mexican free - tailed bats are speedsters in the bat world , designed for fast , long - distance flight . they get their name from their tail , which extends freely beyond their tail membrane .
tuttle , m . d . ( 1994 ) the lives of mexican free - tailed bats . bats , 12 ( 3 ) : 6 – 14 .
tuttle , m . d . ( 1994 ) the lives of mexican free - tailed bats . bats , 12 ( 3 ) : 6 - 14 .
the brazilian free - tailed bat is a highly colonial cave bat that has adapted to human structures , where many now roost . in some parts of the southern united states the species is active year round , roosting in buildings , under bridges , and in caves ; many also migrate southward into mexico and central america . several caves in texas harbor millions of these bats during the summer months . free - tailed bats forage on a variety of flying insects especially small moths and beetles .
copyright bat conservation international © 2018 . all rights reserved . unless otherwise noted , all images are copyright © merlin d . tuttle and / or © bat conservation international .
the densest concentrations of free - tailed bats are found living in bracken cave near san antonio , texas . their colonies can number over 20 , 000 , 000 .
mastiff bat , any of various species of free - tailed bats ( family molossidae ) named for their doglike faces . the eight new world species of bats making up the genus molossus are called mastiff bats . several other genera also include species commonly called mastiff…
s , so called for the way in which part of the tail extends somewhat beyond the membrane connecting the hind legs . some free - tailed bats are also known as
construction type ( certain types of construction are easier or harder to bat - proof ) .
this bat has received considerable attention because it is a known carrier of rabies . with the exception of the eastern red bat ( lasiurus borealis ) , the brazilian free - tailed bat has been reported to the texas department of health ( tdh ) more often than any other species . of 430 specimens reported to the tdh from 1984 to 1987 , 105 ( 24 % ) tested positive for the rabies virus . this is the highest incidence of rabies known for any texas bat . although the total number of confirmed rabies cases is minuscule when compared to the population of bats as a whole , caution should be exercised when one of these bats is encountered , or any species of bat for that matter .
the mexican free - tailed bat ( tadarida brasiliensis ) is a medium sized bat . their fur is reddish to dark brown or gray in color . they have broad , black , forward pointing ears , and wrinkled lips . their tails extend more than one third beyond the tail membranes ; most other bats have tails that are completely enclosed within the tail membranes . their wings are long and narrow .
( 305 mm ) . the free - tailed bat is so named because the tail protrudes noticeably beyond the membrane that stretches between the tail and hind legs . it is the only bat in the eastern united states that has this trait . these bats are medium to dark brown in color , slightly lighter on the belly . their ears are broad and rounded . toe hairs are very long and stiff .
a single free - tail baby bat is born during the summer . young mexican free - tailed bats roost separately from their mothers . babies roost in the highest reaches of the cave , where temperatures are the warmest . the warm conditions are essential for rapid growth and survival . in the large maternity colonies of mexican free - tails , the mother must find her own pup among the thousands . it is thought that she locates her baby by recognizing its individual call .
the mexican free - tailed bat has a range that extends from coast to coast in the us and from texas to argentina . in the us , the bats migrate south in the winter and return to roosting sites in the summer . it is still unknown where the bats go in the winter months .
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abundance of brazilian free - tailed bats in roosts in buildings in texas follows an annual pattern of one peak in spring and another in fall , with general mid - summer and mid - winter lows or periods of complete absence . this pattern complements that of bat abundance in the guano caves . brazilian free - tailed bats in buildings in texas during spring and fall usually are itinerant between tropical latitudes and the mid - latitude guano caves of texas , oklahoma , kansas , and new mexico . sufficient interchange of banded brazilian free - tailed bats has occurred among the guano caves of texas and between those in texas and the ones in neighboring states to demonstrate that individual bats are not compelled to return each year to the cave of their birth . rather , brazilian free - tailed bats exhibit ability to range over great distances and find the widely separated , often well hidden , entrances to the few traditional guano caves and roosts in buildings .
the brazilian free - tailed bat is found in many different habitats from desert through pinion - juniper woodland to pine - oak forests . it inhabits areas from sea level to 3 , 000 metres , and roosts in limestone caves , abandoned mines , under bridges , in buildings and in hollow trees ( 6 ) .
although campbell observed bats of unknown identity catching mosquitoes in the area , there is no documentation that the free - tailed bats from his artificial roosts actually ate them . given the high - speed , relatively low - maneuverability flight of free - tails , it seems unlikely that they would prey extensively on mosquitoes . bats , however , are highly opportunistic ; the larger , also fast - flying , hoary bat
rabies , a disease often associated with bats , is found in members of the brazilian free - tailed bat population . humans who attempt to handle bats without the proper precautions have been infected with rabies , which can be fatal . media sensationalism of this problem has resulted in deliberate eradication attempts and roost destruction ( 7 ) .
on its first attempt at flight , a young free - tail must avoid several mid - air collisions per second , relying on an as yet untested navigation system in a dark cave . although amazingly few serious collisions occur , those that do can break wings or ground a bat long enough to be attacked by swarms of dermestid beetles and their larva that live on the floors of most free - tailed bat caves . as with other bats , the heaviest mortality probably occurs in the first year , perhaps as much as 50 percent .
mexican free - tailed bats live for an estimated seven to eight years . once born it takes a couple years before they start breeding . mature females will give birth to one pup each year for about five years .
free - tailed bats have supported several american war efforts as well . when confederacy ports were blockaded in the latter part of 1863 , a gun powder factory was established near san antonio . the powder ' s most valuable ingredient , saltpeter , was made from local bat guano . during world war 11 , major free - tailed bat caves near san antonio were carefully guarded during top - secret research coded
project x - ray .
* the u . s . air force hoped to use bats as carriers of small incendiary bombs that would be dropped on japan . the project began to lose favor when escaped bat bombardiers set fire to air base barracks and a general ' s car . after being passed on to the navy , and finally the marine corps , the project was canceled .
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free - tailed bats eat insects and roost in tree hollows , caves , and buildings . they are found worldwide in warm regions . most species live in groups , and some form colonies with populations numbering in the millions , such as the
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welcome to our wonderful website that we created to inform you about the amazing tadarida brasiliensis . for those of you who don ' t know this organism , it is also known as the brazilian / mexican free - tailed bat . for our organismal biology course we were told to pick an animal that primarily lives in caves and we decided to research a bat species . this species in particular is distinguished by its brown fur and large ears , medium size , short snout , and wrinkled upper lips . they are also recognized by their
free - tail
that pushes out farther than their legs .
by summer , male and female free - tails will have divided into bachelor and nursery colonies . bachelor groups are relatively small , consisting of dozens to hundreds of individuals , but can number 100 , 000 or more . in contrast , most nursery colonies are large , numbering from the hundreds of thousands to millions . bracken cave is home to some 20 million free - tailed bats , a population that almost doubles when the bats give birth . this is the largest known bat colony in the world .
a particularly well - studied species , the brazilian free - tailed bat exhibits some spectacular behaviour . it forms the largest warm - blooded colonies in the world , emerging to feed at dusk in huge columns of several million individuals . their flapping wings create a sound equivalent to a white - water river and their numbers are great enough to be detected by airport and weather radars ( 5 ) . feeding for longer each night than any other bat species , it travels as far as 31 miles from the roost to the feeding grounds and uses echolocation to find its prey . the brazilian free - tailed bat flies at up to 47 mile per hour in open spaces , foraging with fast , straight flight ( 7 ) . each bat consumes between 200 and 600 insects a night , selecting mainly moths , but also eating beetles , flying ants and leafhoppers ( 3 ) . the brazilian free - tailed bats of texas are estimated to consume from 6 , 000 to 18 , 000 metric tons of insects each year , many of which are agricultural pests ( 2 ) . at dawn , they return to their roosts where they swarm before re - entering . thought to be a predator - avoidance tactic , the bats gather into groups at a great height above the cave , before closing their wings and dropping rapidly in one continuous stream . predators waiting at the mouth of the cave to catch emerging bats include red - tailed hawks , owls , raccoons , opossums , skunks and snakes ( 5 ) .
on this site you will find a variety of information about the brazilian / mexican free - tailed bat . such information includes classification , habitat , form and function , reproduction , and interactions . to see where this amazing creature tadarida brasiliensis fits into the world of organisms please click at the bottom of the page to continue to the classification page . we hope you enjoy learning more about the tadarida brasiliensis !
> free - tailed bats ( family molossidae ) , and horseshoe bats ( family rhinolophidae ) —are well represented in the temperate zones . a few american leaf - nosed bats ( family phyllostomidae ) range into mild temperate regions . several vesper bats range well into canada . …
the flight of brazilian free - tailed bats on leaving and returning to a roost uniformly is accomplished in groups . it is presumed , therefore , that group flight is the norm in this animal . yet , in the roosting clusters , where grouping is also the norm , there is strong evidence that each bat has affinity not to a specific , stable group of acquaintances but to any convenient group of its kind .
despite their rather plain appearance , these are some of the world ' s most intriguing bats . speedsters of the bat world , they have been clocked flying at 60 miles per hour using tail winds , and at altitudes over 10 , 000 feet , higher than any other bat . free - tails can live in an atmosphere more like another planet than earth , one that can quickly kill most other creatures , including humans . and they form colonies larger than any other bat , larger , in fact , than any warm - blooded animal in the world .
in texas , the brazilian free - tailed bat seems to be primarily a cave dweller , and its use of buildings as roosts is likely a relatively recent , possibly expanding practice . only a small fraction of the numbers of bats found in caves is ever found in the total of all roosts in buildings . every town in the brazilian free - tailed bats range in texas is likely to have at least 15 roosts per 5 , 000 human population , but the occupation of buildings is especially common in eastern texas . most roosts in buildings house less than 100 bats at a time , but a few buildings traditionally house many hundreds each year . overwintering in buildings occurs infrequently in the southern gulf coast prairies of texas .
general condition of the building ( older or more deteriorated buildings are typically more expensive because they require more man hours / materials to bat - proof ) .
dozens to millions of brazilian free - tailed bats roost closely together in dark , dry retreats . because of their use of roof underhangs , attics , and narrow spaces between signs and buildings , brazilian free - tailed bats are often called
house bats .
millions arrive in central texas each spring and take up residence in a few particular caves in the balcones escarpment and the edwards plateau . they migrate to mexico , central america , and possibly south america for the coldest winter months . however , in east texas , these bats are non - migratory and are year - round residents .
a member of the molossidae family , the brazilian free - tailed bat has the characteristic mouse - like tail protruding beyond the flight membrane stretched between its hind legs . relatively plain when compared to many bats , this species has brown fur , large ears that are nearly square , and a strongly wrinkled upper lip . however , it is superbly adapted to its aerial lifestyle , having long , narrow wings with pointed tips to enable very fast flight , and long hairs on the toes to judge flight speed and turbulence . the hind legs are short and powerful , making this bat an excellent climber ( 3 ) .
a member of the molossidae family , the brazilian free - tailed bat has the characteristic mouse - like tail protruding beyond the flight membrane stretched between its hind legs . relatively plain when compared to many bats , this species has brown fur , large ears that are nearly square , and a strongly wrinkled upper lip . however , it is superbly adapted to its aerial lifestyle , having long , narrow wings with pointed tips to enable very fast flight , and long hairs on the toes to judge flight speed and turbulence . the hind legs are short and powerful , making this bat an excellent climber ( 3 ) .
mexican free - tails are found in the western united states , south through mexico , central america and into northern south america .
mexican free - tails feed exclusively on flying insects , mostly moths , flying ants , and beetles , according to samples thus far reported . at the turn of the century , charles campbell , the city bacteriologist for san antonio , texas , built large artificial bat roosts to
control mosquitoes
family molossidae ( free - tailed bats ) 100 robust , small to very large species in 16 genera , some ranging into mild temperate regions . tail projects well beyond the well - developed interfemoral membrane ; ears large , rather immobile , often fused to one another , and unusually shaped ; lips and snout often heavy ; eyes…
each free - tail cave is also a potential treasure trove for biotechnologists . microbiologist bernie steele examined guano from bracken cave , finding that a
. although every effort is made by google to ensure translation accuracy , errors may occur . bat conservation international does not guarantee or warrant the accuracy or reliability of this tool .
austin bat conservation international 500 n capital of tx hwy . , bldg . 1 austin , tx 78746 , usa + 1 ( 512 ) 327 9721 1800 - 538 - bats
the annual movement of this animal between texas and mexico may be accomplished by most individuals in a few direct , long - distance flights between guano caves . most adult male brazilian free - tailed bats apparently do not leave the tropical and subtropical portion of the range and play no part in the sociology of bearing and rearing the young .
that free - tailed bats can thrive in this toxic atmosphere may be one of the most remarkable things about them . concentrations of ammonia in free - tail caves can quickly build to levels that are lethal to humans , but the bats survive by lowering their metabolic rates . carbon dioxide then accumulates , both in the bats ' blood and in respiratory mucous , directly proportional to increases in ammonia inhalation . the carbon dioxide neutralizes the ammonia in a buffering mechanism that protects the lungs .
for answers to our 9 most commonly asked questions , please download our free faq’s brochure . if you would like additional information about the risks bats pose to your property , family , and health , or if you would like information on how to remove the bats from yourself , please download our ebook , “the complete guide to bat removal” .
then again , you may not even see a bat , you may just hear weird noises coming from your attic or walls . or , perhaps you catch a whiff of some peculiar smells .
swift fliers with long , slender wings , free - tailed bats are small - eyed , often heavy - snouted bats about 4–13 cm ( 1 . 6–5 . 1 inches ) long excluding the 1 . 5–8 - cm ( 0 . 6–3 . 1 - inch ) tail . their ears are large and are joined across the forehead in some species . except for the
brazilian free - tailed bats appear on the wing several minutes before dark . the famous bat flights at carlsbad caverns are made up almost entirely of this species . one of us ( davis ) watched these bats emerge from the attic of a house one evening . they fell from the exit , dropped nearly to the ground , then zoomed upward and , flying high , disappeared from view , each bat following the general direction of the one in front of it . in foraging , the bats fly rather high  15 m or more as a rule  except when sweeping over some body of water to drink . their flight is rapid and aggressive , reminding one of swifts , and the long , angular , and narrow wings , plus relatively large size , make them easy to identify .
walston and bates ( 2001 ) report a single bat captured in lowland degraded mixed deciduous forest ( nearby one of the few semi - evergreen patches in the area ) at 140 m asl in cambodia .
a number of species of snakes , birds , and mammals prey on house bats at the caves , but the total of this loss of bats is a very small proportion of the total bat population .
despite its name , the brazilian free - tailed bat is actually widespread throughout south , central and north america . it has fairly complex migratory habits ; some populations travel from the extreme north of the range to the extreme south , whilst others remain resident year - round . the largest and most well - known populations are found in mexico and texas , usa . there are nine subspecies in total ; all occupy different ranges and have different migration routes ( 3 ) . the population is thought to total between 95 and 105 million individuals , with bracken cave in texas holding between 20 and 40 million individuals alone ( 2 ) .
lose roosting habitat as old buildings are destroyed . human disturbance and vandalism of key roosting sites in caves are likely the single most serious causes of decline . grossly exaggerated media stories about rabies have led to the intentional destruction of large colonies . one of the most cost - effective ways to help this highly beneficial bat is through key roost protection , public education , and provision of
bat - friendly
bridge designs and other artificial roosts .
the largest populations of mexican free - tailed bats live in central texas and mexico , but they are also common throughout much of western north america , southward through central america , and into the arid and semi arid regions of western and southern south america . they live in many habitats , including urban areas , and range - from deserts to piñon - juniper woodlands and pine - oak forests . although bachelor colonies of free - tails have been found at elevations over 9 , 000 feet , large nursery colonies tend to prefer relatively dry areas below 5 , 000 feet . mexican free - tails typically live in caves , abandoned mines , or tunnels , and also roost in buildings , under bridges , in rock shelters , in hollow trees , and in cliff - face crevices .
whether you live in the outer banks , eastern carolina , the piedmont or the appalachian mountains in the west , you can count on get bats out for all your bat problems . when you need us , we’ll be there .
free - tails spend more time on the wing each night than most bats , consuming countless insects , including many agricultural pests . a large colony collectively can eat literally tons of insects .
at the bottom of the article , feel free to list any sources that support your changes , so that we can fully understand their context . ( internet urls are the best . )
no particular style , size , age , state of repair , or use by man exempts a building from use by brazilian free - tailed bats . the critical feature is whether the building has any accessible small cracks or niches into which bats can retreat into semidarkness during the day . such openings usually are to be found even in the most modern , compact types of structure . one architectural type common in south texas , the spanish style building with clay tile roof , is among the most vulnerable to invasion by brazilian free - tailed bats . the bats roost under the tiles and seldom can be driven out permanently from a roost in a building either by killing those present or by chemical treatment of the surface of the roost . the simplest , most effective method is to close the entrance to the roost . with clay tile roofs this is almost impossible unless the tile is replaced by some other kind of roofing material .
the accumulation , under crowded conditions , of millions of brazilian free - tailed bats per guano cave each summer in texas for the purpose of giving birth and rearing young may be an outgrowth of overpopulation , but it probably is functional in creating favorable conditions for survival of the young . mortality among prenatal and prefledgling babies , as well as among adults , appears to be low . longevity of adults probably is great , with an average of more than 11 years .
adult male brazilian free - tailed bats arriving in texas in spring are still sexually active , but sperm production is waning . their sex glands decrease steadily in size in spring , and reach a resting stage size by early may . the small proportion of the male population which shows no sexual activity is composed principally of the youngest age class . in these , the testes , prostate , and hedonic glands are smaller than the resting stage sizes of the same glands in adult males . in late fall , the few adult males remaining in texas again show some increase in size of testes and prostates , but sperm are absent . peak production of sperm , thus , must occur during winter while the males are in lower latitudes . since the highly disproportionate ratio of male to female brazilian free - tailed bats in texas cannot be explained easily as resulting from higher mortality among males , it must be that most males do not summer in texas .
at dusk , just before dark , brazilian free - tailed bats emerge from their roosts to feed . their flight is rapid and forceful , similar to swifts . their long , angular , narrow wings and relatively large size make them easy to identify . insects such as moths , beetles , flying ants , and june bugs are their sole source of food . it is estimated that house bats eat 6 , 000 to 18 , 000 metric tons of insects annually in texas .
over a 24 - hour period , she may produce as much as a quarter of her own body weight in milk . young free - tails grow rapidly , benefitting from prodigious quantities of this extremely rich
free - tail bats consume enormous amounts of moths and other insects . some roosts are known to contain millions of bats . in those colonies it is estimated that 250 tons of insects can be consumed every night .
in world war ii this species was secretly investigated by the u . s . air force for its potential to carry tiny bombs into japan . bat caves were carefully guarded but the bats refused to cooperate , instead wreaking havoc in air force bases ( 5 ) .
it is believed that this bat may have occurred commonly in kentucky at some time in the past , but the only recent record is of an individual collected at murray , calloway county , in 1971 . the species is to be expected only as an occasional vagrant here .
one roosting spot is located in the urban setting of austin , texas , underneath the congress street bridge , south of downtown . every night 700 , 000 to 1 . 5 million bats ( depending on how many baby bats have been born in the season ) emerge to feed on flying insects in the night sky . the bats in austin are a spectacle that tourists have flocked to see since the bridge construction was made “bat - friendly” in 1980 . interestingly enough , this was done completely by accident . small 1 . 5 inch slats on the bridge’s concrete extend 20 inches into the bridge . this hiding space proved to be an ideal roosting spot for mexican free - tailed bats . today other bridges in texas are being fitted with similar slats to allow for the habitation of bats .
the gestation period of brazilian free - tailed bats appears to be slightly in excess of 90 days . no more than one young is born per year by each adult female . females in texas are almost all pregnant the summer following birth . the left horn of the uterus does not carry an embryo . lactation begins after delivery of the young , and two long mammae are located laterally , each with one functional pectoral teat . a vaginal plug still exists in some females arriving at the texas caves in early spring .
davis believed that migratory movements were rapid , crossing texas in one or a few nonstop flights , covering at least 290 miles a night . given knowledge of bat flight speeds with tail winds , migrating free - tails should be able to cover that distance in no more than five hours , perhaps substantially less , depending on wind velocity . such timing would ensure arrival at stopover caves at optimal times for following other bats in , if necessary , and allow for unanticipated delays due to bad weather .
contains billions of bacteria . he concluded that the cave contains thousands of species of bacteria , many of which may live nowhere else , and most of which we know nothing about . species he identified produce enzymes useful in detoxifying industrial wastes , producing natural insecticides , improving detergents , and converting waste byproducts into alcohol . a large proportion are also potential sources of new antibiotics . stratified guano deposits in free - tail bat caves have also been used to monitor environmental pollution and to investigate prehistoric climatic changes .
to be clear , professional exclusion of bat colonies can be very expensive . but , going about it on your own , or through a cut rate or inadequately equipped pest control service may end up costing you more in the long run ( even if they claim to have experience in
brazilian free - tailed bats can live up to 11 years in the wild . their residency in central texas is marked by the birth and development of their young . females born in texas are almost all pregnant when they return the summer following their birth . most mating in the texas population takes place each spring before the bats ' return journey to the texas caves . male house bats outnumber females at the caves only briefly , in early spring . however , by mid - june , adult females outnumber adult males more than three to one .
mexican free - tailed bats are also known as
guano bats
for the prodigious quantities of droppings that they produce . extraction of guano for use as natural fertilizer was once big business , and some is still sold commercially . from 1903 to 1923 , at least 100 , 000 tons were removed from carlsbad caverns alone and sold to fruit growers in california . according to charles campbell , bracken and frio caves in central texas on average each produced 75 to 80 tons annually in the early 1900s . officials of the southern pacific railroad estimated that , early this century , they annually transported 65 carloads of 30 , 000 pounds each from texas , making bat guano the state ' s largest mineral export before oil . bracken cave , now owned and protected by bci , was still producing from 80 to 85 tons per year in the late 1980s .
mexican free - tailed bats are designed for rapid , long - distance travel . their exceptionally long , narrow wings are geared for relatively highspeed , low - maneuverability flight in open areas . even their short , velvety fur appears to be an adaptation to reduce drag , and their ear orientation appears to form airfoils that contribute lift during flight . they have been clocked at average flight speeds of 25 miles per hour and as high as 47 miles per hour in level flight , but they can also attain speeds of over 60 miles per hour using tail winds .
whilst the brazilian free - tailed bat exists in extremely large numbers and across a great range of countries and habitat types , it is still classed as a threatened species . this is due to its reliance on a relatively low number of roost sites . with the loss of just one roost site , a large proportion of the population could be destroyed . some significant declines have been documented , such as the population of eagle creek cave , which fell from 25 million individuals in 1963 to just 30 , 000 individuals in 1969 . these declines are not fully understood , but several threats are present , particularly from the alteration of roost sites and the use of organochlorine pesticides . insecticides which are found in the bodies of living insects accumulate in the bodies of the bats that eat them in such large numbers , resulting in reduced reproductive success and death ( 7 ) .
don’t delay ! if you do have bats , the longer you allow a colony to roost in a given location , the stronger their instinct will be to stay and even return to that location . basically , time is not on your side when you suspect a bat infestation – it is in your best interest to
mexican free - tails prefer to roost in caves , but will also choose attics , under bridges , or in abandoned buildings . they choose roosts near water . the water attracts the insects they eat , as well as allowing them the opportunity to drink .
these morphological data dictate that cynocephala and mexicana be regarded only as subspecies rather than as separate species , which has been the tendency in the past . recent biochemical genetic studies of these bats have pointed strongly to specific status for each , however . additional study will be required to finally settle the taxonomy of this most interesting bat .
the longest proven migrations are of bats banded by bryan glass in northwestern oklahoma and later recovered up to 1 , 104 miles south in mexico . the northernmost area where he believed any of his bats could have overwintered was 480 miles south in texas . the original bandings were made at four caves less than 48 miles apart , between which the bats intermingled . one bat was recaptured at its cave of birth in oklahoma after having completed eight migratory circuits . free - tails typically return to their home areas , but for these long distance travelers , a home area may include caves over 100 miles apart .
while free - tailed bats are among the more studied , what remains to be discovered about them may be even more fascinating than what we already know . why do so many fly so high ? are they simply catching tail winds to aid in rapid travel to distant locations , or are they actually feeding at such high altitudes ? how do they navigate at high altitudes , given the fact that their echolocation signals reach little more than 100 feet and that cave entrances can be nearly impossible to see from even a few hundred yards ? bats are known to use celestial cues , but whatever cues they are relying on must work both night and day , since flights often arrive in midmorning .
walston and bates ( 2001 ) report a single bat captured in cambodia . the population in barapede cave seems to fluctuate between 40 and 100 as reported by different workers , while the population numbers and trends in the two new locations are unknown . the average count from the barapede cave from 2012 to 2015 is about 82 + individuals ( prabhukhanolkar , pers . comm . 2015 ) .
true southward migration of the free - tails appears not to begin until october . the vast majority of the u . s . population spends the winter mostly in large caves of northern and central mexico . populations living in california , western arizona , oregon , nevada , and southwestern utah apparently live in roughly the same areas year - round , though seasonal movements among roosts are common . there are two main migrations . most of those from the southwest migrate south along the sierra madre occidental and the west coast of mexico at least as far south as the state of sinaloa . free - tails from the great plains typically travel southward through
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predation at entrances to nursery caves increases dramatically as the young bats learn to fly . avian predators are many , with red - tailed hawks and owls the most common , catching flying bats during emergence and occasionally entering caves to catch those roosting near entrances . raccoons , opossums , skunks , and other mammals also prey on the emerging bats , as well as several types of large snakes . given the huge numbers of bats present , such predators likely have relatively little impact .
bats begin arriving in central texas in late february , having migrated from overwintering sites in mexico . active year - round , free - tails do not hibernate . just before their northward migration , they mate . although young males apparently do not reach sexual maturity until their second year , females as young as a year old have been found pregnant .
most populations of the migratory subspecies , mexicana , have normally completed their move into mexico prior to the onset of breeding , whereas cynocephala remains in the united states during the breeding season . this movement pattern would indicate that the two races are reproductively isolated and possibly separate species . however , overwintering populations of mexicana have been discovered in an area of contact between the two in southeastern texas . a colony of mexicana was known to overwinter at the old animal pavilion on the texas a & m university campus in college station ( brazos county ) , which is only 160 km from colonies of cynocephala in extreme eastern texas . a morphological analysis of cranial measurements from free - tailed bats captured near navasota ( grimes county ) found these bats to be intermediate between cynocephala and mexicana . thus , it appears the two subspecies are not reproductively isolated and that they likely interbreed in this part of texas .
as annoying and frightening as they may be ( especially when they are terrorizing your home ) , you shouldn’t kill bats . despite their bad reputation , general lack of physical appeal ( they are ugly ) , and the fact that they and their guano can be very hazardous to human health , bats are actually quite important to our ecosystem . so , for those reasons a responsible property owner should not attempt to eradicate their bat problem using lethal force – also , it’s illegal
the species is threatened from increased tourism , human interference and collections for scientific purposes ( molur et al . 2002 ) . the habitat close to the barapede cave is threatened from submergence due to a proposed dam and river diversion project in the region ( prabhukhanolkar , pers . comm . 2015 ) ( molur et al . 2002 ) . the spread of alien plants species prosopis sp . at the cave mouth is a visible hindrance to bat activities ( pradhan pers . comm . 2003 ) .
even among populations that migrate , not all bats leave . several thousand have been observed overwintering in bracken cave , as well as in concrete crevices beneath the congress avenue bridge , and in old buildings in austin . although free - tails can enter torpor during inclement winter weather , they are not true hibernators . during extremely cold weather , many die . it is unknown why some stay behind .
free - tails spend more time traveling and feeding each night than most bats , in part due to competition from large numbers of roost mates . they typically are on the wing from dusk until dawn . nursing mothers require at least twice as much food as nonreproductive bats , especially as their pups near fledging . at such times , researcher thomas kunz found that they may consume their body weight nightly .
brazilian free - tailed bats appear every year in texas in multimillion numbers to inhabit a few select caves ( known as
guano caves
) located in the balcones escarpment and the adjacent edwards plateau . the total population of these bats that inhabit texas caves during the summer has been estimated at 95 - 104 million . the largest of the caves , bracken cave near san antonio , is thought to hold between 20 and 40 million bats . these same caves have been the summer homes of this animal for at least the past 100 years . few , if any , house bats ever overwinter in the texas guano caves . they spend the depth of winter , from early december to late february , at lower latitudes  probably in mexico , central america , or even south america . in east texas , where these bats are common inhabitants of old buildings and similar structures , they are nonmigratory and are year - round residents of that part of the state .
while most people are unaware of the presence of these bats in their area , mexican free - tails are very much a part of life in central texas , where the largest populations in the united states make their summer homes . these huge colonies , several numbering in the millions each , are where mothers congregate to give birth . the importance of these nursery sites is enormous ; bats born here help replenish colonies throughout much of the southwest and other areas .
description . a medium - sized bat with broad ears , large feet , and terminal half of tail free ; ears broad , extending to tip of snout when laid forward , apparently , but not actually , united across forehead , with a series of wartlike structures on anterior rim ; tragus small and blunt ; second joint of fourth finger 6 - 9 mm long ; feet with distinct white bristles on sides of outer and inner toes ; ratio of foot to tibia about 75 ; pelage short ( 3 - 4 mm ) and velvety ; upperparts varying from reddish to black ; underparts slightly paler ; membranes and ears blackish . dental formula : i 1 / 2 or 1 / 3 , c 1 / 1 , pm 2 / 2 , m 3 / 3 x 2 = 30 or 32 . the total number of lower incisors is variable , usually six , sometimes four , occasionally five . external measurements average : total length , 95 mm ; tail , 38 mm ; foot , 10 mm ; ear , 19 mm ; forearm , 42 mm . weight , 11 - 14 g .
in his research gary mccracken ( left ) marked pairs of mothers and nursing young , discovering that mother bats did not randomly nurse any pup , as had been previously believed . after her pup is born , mother and young spend up to an hour getting to know each other ' s scent and vocalizations ( right ) . she roosts separately from her pup , returning only to nurse it . remarkably , among the many thousands of other pups covering the cave walls ( opposite page ) , she will find her own young . note the other bat in the upper right corner , nearly buried by pups .
be enough to warrant a comprehensive inspection . why would we say that ? the fact is , these creatures are reclusive by nature and typically only come out at a time of day when they are difficult to see ( this is obviously a strategic advantage both for their own hunting purposes as well as protection from predators ) . and , it is rare ( although it can happen ) that a bat will randomly get trapped in your home , so if you happen see one or one gets into your home , then it’s likely that there are more and / or that they have been there for a while .
at dawn , the free - tails return to their roost in an event sometimes said to be even more spectacular than evening emergences . richard davis and his fellow researchers observed flocks of thousands of bats each , first becoming visible 4 , 900 to 8 , 200 feet above bracken cave . these high - altitude flocks sometimes flew past the entrance at speeds of almost 60 miles per hour before turning around and diving toward the entrance . beginning about two hours before sunrise , small groups built up into a continuous diving stream , reaching the greatest density about 30 minutes before dawn . the first arriving bats came in shallow , zigzagging glides , but as flight density increased , they formed a continuous stream of individuals dropping out of the sky into the mouth of the cave . each was executing a rapid series of free falls with closed wings , alternating with abrupt , brief wing openings to control speed and direction . some groups dropped nearly 10 , 000 feet at speeds estimated to exceed 80 miles per hour .
please subscribe now ! urltoken caves are without question the number one habitat we think of when it comes to bats , but it might surprise you to know that there could literally be thousands of bats living right under a place many of us use every single day . . . the road ! this week coyote has teamed up with wildlife expert philip
wildman
rakoci to seek out the mexican free - tail bat under the dark desert highways of arizona . most people are terrified of bats but coyote and wildman phil are determined to show you why these stealthy little predators are nothing to fear and are actually pretty darn cute ! special thanks to wildman phil for all of his help on this episode and make sure to check out his work in animal conservation and education at urltoken breaking trail leaves the map behind and follows adventurer and animal enthusiast coyote peterson and his crew as they explore a variety of wildlife in the most amazing environments throughout north america ! watch more breaking trail : urltoken subscribe now ! urltoken find more info at : urltoken coyote peterson on twitter : urltoken coyote peterson on facebook : urltoken coyote peterson g + : urltoken
as large numbers of bats leave the cave , they begin appearing in groups of tens to hundreds of thousands under highway bridges and in almost any other available place . during 1993 , an extremely dry year in central texas , so many free - tails attempted to move under austin ' s congress avenue bridge that tens of thousands were forced to hang out in the open on the concrete pillars . with three - quarters of a million bats of its own , the bridge is the site of the largest urban colony of bats in the world .


granulifusus hayashii is a species of sea snail , a marine gastropod mollusk in the family fasciolariidae , the spindle snails , the tulip snails and their allies .

granulifusus hayashii

genus and description : granulifusus hayashii , 42 . 5 & 45mm , f + +
family : fasciolariidae born : 1961 , habe genus and description : granulifusus hayashii , 50 mm , f + + origin : collected by a local fishermen by nets off aliguay island philippines , july 2013 .
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version 43 . 0 went live 11 / 6 / 2018 - i hope that the majority of issues have been fixed . my email address is on the home page if you see anything wrong .
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in : okutani , t . ( ed . ) , marine mollusks in japan . tokai university press , tokyo , 505 - 517 ( in japanese ) .
occurrence record in darwincore format ( elements of obis schema and some of dwc1 . 4 )
- note : several protected species are illustrated here only for identification purposes . they are not for sale . - the photos in our gallery are in most cases just a sample from our stock , except when only one specimen is offered . we try to match the original color but it can vary if your screen is not correctly adjusted ( gamma correction ) .


the hairy-legged vampire bat ( diphylla ecaudata ) is one of three extant species of vampire bats .

it mainly feeds on the blood of birds , but can also feed both on domestic birds and humans .

this vampire bat lives mainly in tropical and subtropical forestlands of south america , central america , and southern mexico .

it is the sole member of the genus diphylla .

hairy - legged vampire bat

hairy - legged vampire bats are the rarest of the three vampire bat species ( mccarthy 1987 ) .
the flying mammals are well known to feed on blood , however , the hairy - legged vampire bat and white - winged vampire bat subspecies predominantly feast on birds .
schutt , jr . , w . , j . altenbach . 1997 . a sixth digit in diphylla ecaudata , the hairy legged vampire bat .
hairy - legged vampire bats are nocturnal . they roost either alone or in small groups of 12 or less . in one study ,
texas parks & wildlife , 1994 .
hairy legged vampire
( on - line ) . accessed march 21 , 2001 at urltoken .
reddell , j . r . 1968 . the hairy - legged vampire , diphylla ecaudata , in texas . journal of mammalogy 49 : 769 .
vampire bats ( desmodus rotundus ) are bats that feed on blood . this particular habit in certain animals is known as ‘hematophagy’ . there are only three bat species that actually feed on blood : the common vampire bat ( desmodus rotundus ) , the hairy - legged vampire bat ( diphylla ecaudata ) and the white - winged vampire bat ( diaemus youngi ) .
, commonly referred to as hairy - legged vampire bats , range from reddish brown to sooty brown in color . they have a narrow , hairy interfemoral membrane and a pug - nosed snout . hairy - legged vampire bats are distinguished by their typically smaller body and ears than other vampire bats . they also have a total of 26 teeth , more than other vampire bat species . hairy - legged vampire bats have highly modified upper incisors . these incisors are larger than the canines and occlude against each other so that they are continuously sharpened to a very fine edge . the outer incisors are much reduced ( carattini 2001 ; texas parks and wildlife 1994 ) .
vampire bats only come out to feed when it is fully dark . like fruit - eating bats and unlike insectivorous and fish - eating bats , they only emit low - energy sound pulses . the common vampire bat feeds mostly on the blood of mammals , whereas the hairy - legged vampire bat , and the white - winged vampire bat feed on the blood of birds .
none of these theories about the origins of vampire bats has been proved . evidence from proteins suggests that vampire bats have been around for 6 to 8 million years . these are the dates when the hairy - legged vampire bats separated from the white - winged vampire bats and the common vampire bats .
vampire bats are among the most fascination of mammals , although we know relatively little about the details of their lives . common vampire bats , as their name implies , are the most widespread of vampires . they adapt well to captivity and often are exhibited in zoos . these bats may be among the best studied in the world . hairy - legged vampire bats and white - winged vampire bats are less common and are less often caught by biologists . while common vampire bats may feed on the blood of mammals or birds , the white - winged vampire bat and the hairy - legged vampire bat are thought to prefer bird blood .
scientists in brazil have discovered that hairy - legged vampire bats have resorted to feeding on humans , sparking fears that the rabies and hantavirus - carrying creatures could cause an increase in disease in humans .
…or desmodus , youngi ) and the hairy - legged vampire bat ( diphylla ecaudata ) are the only sanguivorous ( blood - eating ) bats . the common vampire bat thrives in agricultural areas and feeds on livestock such as cattle , pigs , and chickens . the other two vampires are primarily restricted to intact forests , where they feed on birds , reptiles , …
vampire bat colonies appear to be naturally decimated by rabies virus infections and discrete colonies may fall to population densities incapable of maintaining transmission . the so - called ‘migration’ of vampire bat - associated rabies described from south america ( for detailed discussion of the epidemiology of vampire bat rabies , see
) , and wildlife rabies control programs are still nonexistent ( other than vampire bat control ) .
) . cyclic changes in vampire bat populations could drive cyclic and periodic epidemics of cattle rabies caused by vampire bat transmitted rabies . in regions of central and south america , areas affected by vampire rabies experience outbreaks every 2 to 3 years (
because hairy - legged vampire bats almost always feed by taking the blood of birds , they rarely attack humans . if they were to bite a human , the wounds would not be serious . however , it is possible for them to transmit rabies and other diseases through those wounds . because hairy - legged vampire bats may occasionally take blood from livestock and trasmit diseases , they are potentially economically important to cattlemen and sportsmen of texas as a reservoir of bovine paralytic rabies ( texas parks & wildlife 1994 ; carattini 2001 ; britannica 1999 - 2000 ) .
let ' s follow the process as a common vampire bat sets out for a night ' s foraging .
while in the wild , this species of vampire bat may live about 9 years . in captivity they may survive much longer (
vampire bats
2001 ) .
perhaps as a result of being so misunderstood , vampire bats and many other bat species are at risk of extinction .
does not eat for more than 2 nights in a row then it will die from starvation . it has been estimated that about 1 / 3 of hairy - legged vampire bats does not eat each night , they must then rely on shared food from roost mates ( schutt & altenbach 1997 ; tomlinson ; texas parks & wildlife 1994 ) .
carattini , l . 2001 .
the vampire bat
( on - line ) . accessed march 21 , 2001 at urltoken .
source / reference article learn how you can use or cite the vampire bat article in your website content , school work and other projects .
vampire bats tend to live in almost completely dark places , such as caves , old wells , hollow trees and buildings . colonies can range from a single individual to thousands . vampire bats often roost with other species of bat .
studies of common vampire bats in costa rica indicate that it is risky to depend upon blood as the only source of food . each adult common vampire bat has a 7 % chance of not feeding on any night . this means that about once every 25 nights the bat will miss its meal and go hungry . common vampire bats cannot survive two nights without meal , so fasting is dangerous . for young bats , the risk of not finding food is higher , 33 % . so , twice a week each young common vampire bat will probably miss a meal .
) . such areas have been associated with high incidences of vampire bat rabies transmission to both humans and herbivores and have identified the circulation of specific virus lineages within localized geographical locations . it is hypothesized that topological features such as dense jungle may restrict vampire bat movement and that this results in the generation of viral sublineages circulating within distinct regions (
further surveys are needed in the amazon region to confirm the species presence or absence . as for other vampire species , education programs about vampire and rabies control programs are required . the species should be excluded from vampire control programs .
there are no major threats throughout its range . there are vampire control programs .
once the common vampire bat locates a host , usually a sleeping mammal , they land and approach it on the ground . a recent study found that common vampire bats can , in addition to walking , run at speeds of up to 1 . 2 metres per second . vampire bats locate a suitable place to bite their victims using their infrared sensors .
shedding the plasma makes taking off from the ground easier . but the bat still has added almost 60 % of its body weight in blood . to take off from the ground the bat must generate lots of lift . common vampire bats have very long thumbs . as the bat prepares to take off it crouches close to the ground and then , by contracting its chest muscles , flings itself skyward . the thumbs provide extra leverage for takeoff . usually within two hours of setting out , the common vampire bat returns to its roost and settles down to spend the rest of the night digesting its blood meal .
the tank is the bat ' s stomach , and its lining rapidly absorbs the blood plasma . in turn , the circulatory system shunts the plasma to the kidneys . from there it passes to the bladder and out of the bat . within 2 minutes of beginning to feed , a common vampire bat begins to urinate . the urine is very dilute - - no wonder , it is the plasma from that blood meal . the plasma is heavy but contains no nutritive value , so the bat benefits from leaving it behind .
tropics . only one specimen of a vampire bat has ever been found in the united states , in texas in 1967 , and it probably had wandered some 700 km north from its breeding population . .
common vampire bats usually roost in hollows , so they may be found in caves , hollow trees and buildings . the bat leaves its roost just after dusk , setting out to find a meal . the relatively long and narrow wings - - providing a high aspect ration on high wing loading - - make it possible for the common vampire bat to fly rapidly and consume relatively little energy in doing so .
vampire bats are not an endangered species and have a conservation status of being ‘least concern’ .
) . alongside this , both deforestation and the introduction of prey species such as livestock into new areas provide a food source that will help increase populations of vampire bats . the white - winged vampire bat is found from mexico to southern argentina and is also present on the islands of trinidad and isla margarita . in trinidad , white - winged vampire bats have been found cohabiting roosts in caves with
is one of three species of vampire bats , all of which are found only in the new world tropics . only one specimen of a vampire bat has ever been found in the united states , in texas in 1967 , and it probably had wandered some 700 km north from its breeding population . .
vampire bats can live up to 9 years in the wild and up to 19 in captivity .
it sounds like the stuff of horror fiction , but scientists have raised health fears after a species of disease - carrying vampire bat , previously thought to mostly diet on birds , has been discovered feeding on human blood .
the feeding pattern of the vampire bat adds a layer of complexity to its anatomy . because they often do not find host organisms for many hours and may have to fly a long distance to do so , vampire bats usually feed in enormous quantities . this influx of proteins can however make the bat too heavy to fly . vampire bats have so much stealth that they can drink for 30 minutes without awakening the animal . if vampire bats do not get blood for two days , they will eventually die , but that is less likely to happen . female bats are generous and will give their blood to other bats who lack food .
unlike fruit - eating bats , the vampire bats have a short , conical muzzle without a nose leaf . instead they have naked pads with u - shaped grooves at the tip . the common vampire bat also has specialised infrared sensors on its nose , by which it perceives temperature . a nucleus has been found in the brain of vampire bats that has a similar position and has similar histology to the infrared nucleus of infrared sensitive snakes .
radio - tracking studies suggest that a foraging common vampire bat returns to a general area where it has found prey before . having reached its foraging area , the bat must find and select a victim . the fine details of its search and selection behaviour remain unknown . however , the inferior coliculus , part of the bat ' s brain thatt processes sound , is specialized for detecting the regular breathing sounds of a sleeping animal such as a cow . the bat lands on the ground near its intended victim and approaches on foot . among bats , common vampires are the most agile on the ground , hopping about like ballet dancers .
2001 .
vampire bats
( on - line ) . accessed march 21 , 2001 at urltoken .
, native to the tropics of central and south america . there are three recognised sub - species of vampire
the human population across central america and vast regions of south america remains at risk of rabv transmission from bats , in particular , hematophagous or vampire bats . there are only three species of hematophagous bat that consume blood exclusively as their diet : the
vampire bats have burnt amber coloured fur on their backside while soft and velvety light brown fur that covers their belly . vampire bats have a wingspan of about 8 inches and a body about the size of an adults thumb .
apparently , the bats urinary system accommodates this by releasing dilute urine consisting of a lot of water and fewer solutes . however , when the bat is resting , a new problem is faced . the large amounts of protein create excess urea and must be disposed of . the urinary system of the vampire bat then uses various hormones to make concentrated urine which consists of more urea and less water .
groom each other and help other bats in need . by learning to recognize other bats in a colony through voice and smell , bats can communicate with each other when necessary . a bat can beg for food and another bat who has built a strong bond with that bat will regurgitate blood for it to eat , demonstrating reciprocal social behavior . these bats are shy , quick to take flight , and seem to rapidly vacate roosts once they have been disturbed by humans (
vampire bats
2001 ; texas parks & wildlife 1994 ) .
existing data on colonies of bats in the united states : summary and analysis of the u . s . geological survey ' s bat population database
) is compatible with a traveling wavefront of rabies propagating among neighboring vampire bat metapopulations , whereby populations are decimated in the trough behind the traveling wavefront and require time to recover above some critical population density to support rabies virus transmission . control of population densities below the
then crawls up to it ' s generally sleeping victim , before biting it and feeding on the flowing blood . vampire
is present across much of latin america . it has been postulated that the introduction of domesticated livestock to the americas has increased vampire bat densities considerably over the past 300 years through an increase in available prey species such as cattle , horses , goat , and sheep (
vampire bats are members of the new world leaf - nosed bats , the phyllostomidae . all three species of living vampire bats occur in south and central america . fossils of three other species reveal that several thousand years ago vampire bats were more widespread . they are known from cuba and from as far north as west virginia and the northern califfornia , places where they no longer occur . with the exception of captive amimals , vampire bats have never been found outside of the new world .
do not suck the blood of their victims , but inside lap it up using their grooved tongue as it flows out of the wound . chemicals in the vampire bat ' s saliva both stop the blood from clotting and numb the area of skin around the bite to prevent the
there is a heat ( infrared ) sensor on the nose - leaf of common vampire bats , permitting them to locate an area where the blood flows close to the skin . if there is fur on the skin , the common vampire bat uses its canine and cheek teeth like a barber ' s shears to clip away the hairs . the bat ' s razor - sharp upper incisor teeth are then used to make a quick cut , leaving the 5 - mm wound described above . the upper incisors lack enamel , making it easier to keep them razor sharp .
a vampire bat finds its prey with echolocation ( use of ultra - high frequency sounds for navigation ) , smell , and sound . they fly about one metre above the ground . then they use special heat sensors in their noses to find veins that are close to the skin .
sources : 1 . david burnie , dorling kindersley ( 2008 ) illustrated encyclopedia of animals [ accessed at : 09 mar 2011 ] 2 . david burnie , kingfisher ( 2011 ) the kingfisher animal encyclopedia [ accessed at : 09 mar 2011 ] 3 . david w . macdonald , oxford university press ( 2010 ) the encyclopedia of mammals [ accessed at : 09 mar 2011 ] 4 . dorling kindersley ( 2006 ) dorling kindersley encyclopedia of animals [ accessed at : 09 mar 2011 ] 5 . richard mackay , university of california press ( 2009 ) the atlas of endangered species [ accessed at : 09 mar 2011 ] 6 . tom jackson , lorenz books ( 2007 ) the world encyclopedia of animals [ accessed at : 09 mar 2011 ] 7 . vampire bat behaviour ( date unknown ) available at : [ accessed at : 09 mar 2011 ] 8 . vampire bat feeding ( date unknown ) available at : [ accessed at : 09 mar 2011 ] 9 . vampire bat lifecycles ( date unknown ) available at : [ accessed at : 09 mar 2011 ] 10 . vampire bat senses ( date unknown ) available at : [ accessed at : 09 mar 2011 ] 11 . vampire bats ( date unknown ) available at : [ accessed at : 09 mar 2011 ]
the feeding process usually takes about a half an hour . an adult may consume about 5 teaspoons of blood , which is about half of its body weight . after the bat feeds , it urinates continuously until it is light enough to fly again . the longest this bat can go without eating is 2 nights . if
common vampire bats will almost always have only one offspring per breeding season . each colony will typically contain only one reproducing male , with around twenty females and their offspring . vampire bats need blood at least once every few days to survive . if they cannot get blood , they will approach another vampire bat whilst roosting , asking for a blood ‘transfusion’ . the blood is exchanged mouth - to - mouth in a motion that looks very much like kissing . their babies use tiny thumbs in the middle of the wing to cling on the mothers furry belly .
participate in altruistic feeding , whereby a bat that has fed will regurgitate blood for one that has not . this could provide a further opportunity for transmission of virus .
tomlinson , d .
natural history of the vampire
( on - line ) . accessed march 20 , 2001 at urltoken .
vampire bats have small ears and a short tail membrane . their front teeth are specialised for cutting and their back teeth are much smaller than in other bats . their digestive systems are also specialised for their liquid diet . the saliva of vampire bats contains the substance , ‘draculin’ , which prevents the victims blood from clotting . vampire bats therefore , lap blood rather than suck it as most people imagine .
vampire bats are amazingly well - equipped to live on a diet of blood and only blood - something no other mammal in the world does . its teeth are so razor - sharp that the bird or mammal it feeds on usually does not even feel the tiny bite it inflicts . the bat ' s saliva contains a chemical that keeps the blood flowing , and its tongue is grooved - the bat uses it almost like a straw . as soon as the bat feeds , it urinates . its body retains the nourishing part of the blood but gets rid of the water , so that it does not have to fly away carrying an extra load of weight .
encyclopaedia britannica , 1999 - 2000 .
vampire bat
( on - line ) . accessed march 21 , 2001 at wysiwyg : / / 42 / http : / / www . britannica . com / b . . . 1 + 1 + 74754 , 00 . html ? query = diaemus % 20youn .
vampire bats are amazingly well - equipped to live on a diet of blood and only blood - something no other mammal in the world does . its teeth are so razor - sharp that the bird or mammal it feeds on usually does not even feel the tiny bite it inflicts . the bat ' s saliva contains a chemical that keeps the blood flowing , and its tongue is grooved - the bat uses it almost like a straw . as soon as the bat feeds , it urinates . its body retains the nourishing part of the blood but gets rid of the water , so that it does not have to fly away carrying an extra load of weight .
when a common vampire bats rerturn to the roost , they often meet face - to - face and groom one another . a bat that fails to feed uses this face - to - face contact to beg blood from a roostmate . the successful bat may then regurgitate some blood to the unsuccessful one . the cost of the doner is relatively small , particularly since before the month is out it will need a donation itself . the benefit to the receiver is high , for it is survival .
other blood - feeding animals such as ticks , insects and leeches do not face the same problem as vampire bats because they can go for weeks , months or even years without a meal . vampire bats , however , are warm - blooded , and the cost of staying warm means that fasting is soon fatal . the costs of keeping warm account for the absence of vampire bats from cooler parts of north , central and south america .
5 . white - winged vampires will also take their meals in the trees instead of the barnyard . while a bird roosts on a branch , the bat sneaks up on it from below , crawling along the underside of the branch and staying out of sight . once it’s directly underneath its prey , the bat bites the bird’s big rear - pointing toe and drinks its fill .
vampire bats are the only known mammals that exist entirely on a diet of blood . their preferred prey are lareg birds , horses , cows and pigs .
genetic analyses have revealed that colonies of common vampire bats are mixtures of relatives and nonrelatives . this means that the social support provided by the colony transcends the business of helping relatives . cooperation may be one of the central keys to the success of common vampire bats . we would expect that common vampire bats that are not part of the colony would not get blood from the members of the group . giving blood appears to depend upon the prospect of a donation in return .
the bat then begins to use its tongue in the wound as well as its saliva . the action of he tongue keeps blood flowing , while grooves on the underside of the tongue draw blood toward the bat ' s mouth . meanwhile , the saliva has at least three active ingredientts that promote bleeding . one is an anticoagulant that counters the clotting defences . a second keeps red blood cells from sticking together and a third inhibits the constriction of veins near the wound . it may take the bat about 20 minutes to fill its tank ; then it is time to take off and return to its roost .
each vampire bat , whatever the species , needs about two tablespoonful of blood every day . this represents about 60 % of the bat ' s body weight , or 20 g of blood . the bats extract this blood through a wound they make with their front ( incisor ) teeth . the wounds are approximately 5 mm deep and 5 mm in diameter and do not cut arteries or veins . if you made a wound this size on your body , it would produce about one drop of blood or less than a gram . it appears that vampire bats are
one stop shoppers ,
feeding on one victim each night . getting 20 g of blood from a wound that normally produces just one drop is a specialized business .
7 . unlike its cousins , the common vampire bat eats solely on the ground , and it has evolved to be as nimble there as it is in flight . while most other bats are awkward crawlers , the common vampire can move with a quick run - like gait or hop along the ground , supporting its weight on its hind legs and using its wings and elongated thumbs to steer and push off of the ground . this comes in handy for chasing after prey on the move and for jumping out of the way if it needs to .
4 . white - winged vampires have a few tricks for feeding on domestic chickens without startling the birds . sometimes , they’ll approach a hen and mimic a chick by nuzzling up to her brood patch . this featherless section of skin on the hen’s underside is densely packed with blood vessels and is used to transfer heat to her eggs or chicks during nesting . the vessels make an easy target for the bat , and if the hen thinks it ' s her baby cuddling up to her , she’ll sit on the bat to give it access to drink . other times , the bats will climb up on a hen’s back , mimicking the touch and weight of a mounting rooster and sending the hen into the crouching stance they take before mating . the bat can then shimmy up to the hen’s neck for a bite and she’ll stay in that position until the bat hops off .
biologists have argued for years about whether vampire bats should be housed in their own family ( the desmodontidae ) or included among the new world leaf - nosed bats ( the phyllostomidae ) . people on both sides of this argument agree that the new world leaf - nosed bats are the vampire bats ' closest relatives . vampire bats are highly specialized for feeding on blood . this situation raises several questions : how did blood - feeding arise in bats ? why is it restricted to the new world tropics ? when did it appear ?
three theories account for the origin of vampire bats . the first proposes that vampire bats originated from fruit - eating bats . this theory suggests that large , strong upper incisor teeth would make fruit bats well suited to switching to blood . this theory does not explain why blood - feeding did not also appear among the old world fruit bats , the pteropodidae .
people are often surprised to learn that vampire bats are not found in central europe . it seems common to suppose that human myths about vampires and stories about dracula somehow involve vampire bats . the truth is that vampire bats got their names from human myths about vampires . in many human cultures , vampires are people who return from the dead to feed on the blood of living people . after the bats were discovered by european explorers , they were given the name vampire , denoting blood - feeding . the blood - feeding were well known to many human inhabitants of south and central america well before their discovery by europeans . bram stoker , intrigued by the publicity surrounding bats that fed on blood , included bats in his book dracula .
is so fast that they must feed every two days to ensure their survival ( blood is very nutritious containing high amounts of water ) . the nearly 20 teeth in the bat ' s mouth are mostly redundant due to their liquid
to hunt for food . despite being incredibly strong fliers , the design of their arms and legs means that they can also move about on the ground with surprising speed and agility . vampire
fears about vampire bats are fueled by a lot of misconceptions . a common one is that the bats bite the throats of their human victims . this is very far from the truth !
) of a vampire bat rabies virus isolate . as previously reported , a decrease in feeding was observed following the onset of clinical disease in those that succumbed leading to dehydration and reduced salivation . infected bats were swabbed prior to and following the onset of clinical disease . no viral material was detected in swabs from clinical animals ; however , virus isolation in tissue culture was successful from three bats that survived infection after 6 (
ellison , l . e . , t . j . o ' shea , m . a . bogan , a . l . everette , and d . m . schneider . 2003 . existing data on colonies of bats in the united states : summary and analysis of the u . s . geological survey ' s bat population database . monitoring trends in bat populations of the united states and territories : problems and prospects . u . s . geological survey 127 - 237 .
bats are firmly rooted in western vampire lore , but only three species , out of some 1100 in the order chiroptera , actually have a taste for blood . the vampire bats are the only mammals in the world that live on blood alone , and the unique challenges of that diet make them some of the most specialized , fascinating and downright weird animals that nature has to offer .
when you remember how much blood is available in different sized mammals and birds , it is obvious that one stop shopping for vampire bats will only work with large prey . the availability of large prey and the difficulty of obtaining large amounts of blood probably explains why vampire bats are no bigger than 40 g . fossil species that probably weighed about 60 g may have had more large mammals and birds to tap .
, it is the bite itself that can cause problems becoming infected or diseased . farmers have not only attempted to poison entire colonies but are also known to destroy their daytime lairs using dynamite , often eliminating thousands of vampire
) , but it is a solitary bat and does not form groups like desmodus . there are no lingual grooves under the tongue as in desmodus and diaemus , but it does have a groove along the roof of the mouth which may serve as a
blood gutter
.
description . a relatively large , sooty - brown bat with no tail ; a narrow , hairy interfemoral membrane ; short , rounded ears ; and a short , pug - nosed snout . the dentition is highly modified with the middle upper incisors larger than the canines ; the outer incisors very small and set so close to the canines that they are easily overlooked ; the crowns of the outer lower incisors seven - lobed , fan - shaped , and more than twice as wide as the inner lower incisors ; premolars and molars very small and probably non - functional . dental formula : i 2 / 2 , c 1 / 1 , pm 1 / 2 , m 2 / 2 x 2 = 26 . external measurements average : total length , 85 mm ; foot , 13 mm ; forearm , 53 mm . weight , 30 - 40 g .
) . cattle may also be infected from dogs or foxes , in areas where such rabies is endemic . in north america , predominant sources of infection are from wild carnivore species , such as from skunks in the midwest and raccoons in the east . in addition , cattle may infrequently become infected with insectivorous bat rabies virus variants . among 47 rabies - positive bovine samples provided to the centers for disease control and prevention from various state health departments within the us , 8 % ( 4 / 47 ) were bat - associated variants ( j . s . smith , personal communication ) .
produces an anticoagulant in their saliva that is about 20 times more powerful than any other anticoagulant known . the saliva has been used as a blood - thinning drug to treat heart attacks and strokes in humans (
vampire bats
2001 ) .
) include an alpha form that is more fibrin dependent than t - pa . its half - life is also longer than that of t - pa . experimental studies have shown that the recombinant alpha - 1 form and the bat plasminogen activator may be superior to t - pa in sustaining recanalization and may cause less fibrinogenolysis .
) include an alpha form that is more fibrin - dependent than t - pa . its half - life is also longer than that of t - pa . experimental studies have shown that the recombinant alpha - 1 form and the bat plasminogen activator may be superior to t - pa in sustaining recanalization and may cause less fibrinogenolysis .
in mammals and birds , which are thought to be the usual prey of vampire bats , blood amounts to 6 - 10 % of the animal ' s weight . this means that a 100 - kilogram person ( 220 pounds ) would have no more than 10 kilograms of blood , or a 1 , 000 - kilogram moose would have 100 kilograms of blood . a 450 - gram ( 1 - pound ) rat would have no more than 45 g of blood , and the vampire bats themselves have only 4 g of blood .
9 . vampires are known to share meals with each other . mother bats regurgitate previously - drunk blood for their offspring until the babies are old enough to hunt on their own . other related bats and even unrelated ones have also been observed puking blood up for one another in a reciprocal arrangement . if a bat can’t find a meal one night , one of its roost - mates may share some of its meal . in the future , the bat who was fed is highly likely to return the favor . if it cheats , or takes a blood donation without ever giving back , it may find that it gets the cold shoulder the next time it needs help .
but inside land on the ground close by and crawl up to it , where they are able to detect veins close to the skin ' s surface with precision , thanks to their heat - sensing nose . using it ' s set of sharp front teeth , the vampire
efforts to eradicate who colonies at a time however , have led to population declines in certain areas . scientists have also discovered though that the anti - coagulant found in the bat ' s saliva , proves to more effective at preventing blood clotting than any medicine , meaning that this could have significant positive implications for patients with strokes or heart attacks .
vampire bats very rarely bite people because they apparently dislike human blood . the three species of bats are quite different from each other and are therefore placed within different genera ( no other species are currently classified in any of the three genera concerned ) . but they are related .
is primarily an inhabitant of tropical and subtropical forestlands . they can be found in both mesic , forested and arid , open areas . during the daytime these bats roost in caves , mine tunnels , hollow trees , or abandoned buildings (
vampire bats
2001 ; texas parks & wildlife 1994 ) .
the food of diphylla is the blood of warm - blooded vertebrates , mainly birds , including domestic chickens . ernest walker reported that diphylla attacks the legs and cloacal region of chickens . one bat was
observed alighting on the tail of a chicken , hanging by its hind legs and biting the exposed skin in the cloacal region , and then lapping up the blood while in an upright position .
common vampire bats live together in structured societies that provide a network of social support . like other bats , common vampires are long - lived . banding studies suggest that some survive almost 20 years in the wild . banding studies also reveal that individuals remain in their roosting groups for at least three years and probably for their entire lives . colonies of common vampire bats usually include one adult male with several females and their young . the bats may not all roost together at any one time , for they move between several roosts within the home range of the colony . females that roost together often forage in the same general area , and several bats may line up , feeding in succession at a wound .
the third theory proposes that the ancestors of vampire bats began to feed on insects and insect larvae they found in wounds on large animals . this theory notes that insectivorous bats often feed where there are many insects and some of them adjust their hunting style according to the situation . throughout the tropics , flies known as screwworms lay their eggs in wounds and their larvae develop into large masses . this theory identifies strong , sharp upper incisor teeth as the key to why blood - feeding only appeared in new world bats . many new world leaf - nosed bats have large , strong upper incisors . these teeth are lacking from those old world bats with flexible foraging behaviour , namely the slit - faced bats and the false vampire bats .
feeding for common vampires is often risky , given that their preferred victim , the domestic cow , is several thousand times larger than they are . they usually bite cows on the area of the leg just above and behind the hoof , since the skin is relatively thin and the blood vessels run close to the surface . one step backwards , and a bat could be squashed if it hadn’t figured out how to run or make impressive three - foot leaps into the air .
) . this study corroborated earlier observations that are of general interest . first , the detection of early clinical signs was not possible merely through observation , and it was not until animals were separated and forced to move around that disease signs were evident . this suggests that bats that have become separated from a roost with clear clinical disease may be in a late stage of infection , although it remains unknown how clinical disease progression correlates with virus excretion . this may have significant consequences for contact and transmission rates within bat species . second , as reported previously (
vampire bats do not kill their prey . they only take about a teaspoon or two of blood at a feeding . since bats rarely carry rabies , there is little chance their victims will die from that disease . however , it has been said that some do carry the disease and it is not the blood - sucking that kills the victim , but the transfer of the rabies . i guess it depends upon species and whether that species has contracted the disease .
found in all types of forest , mainly at low elevations . roosts in caves and mines , rarely in hollow trees . individuals are well spaced in the roost , and group size is usually small , although a group of more than 500 was found in a cave in puebla , mexico , where numbers were much reduced in january , perhaps indicating seasonal movements or migration . avian blood may predominate in the diet of wild individuals , although cattle are occasionally exploited . unlike other vampires , this attractive bat is gentle and easy to handle . reproduction occurs year around ( reid 2009 ) . also occurs in open areas ( aguiar pers . comm . ) .
the second theory suggests that the ancestors of vampire bats acquired a taste for blood by feeding on ticks and other blood - feeding ectoparasites of large mammals . today in africa , birds known as ox - peckers make their living by feeding on ticks . it appears to be a viable life - style . but as the ox - peckers show , both ticks and blood - feeding ectoparasites and large mammals occur in africa . again we are left with the question , why did blood - feeding bats not appear in the old world tropics ?
8 . to meet their energy needs , vampire bats need to drink about an ounce of blood at every meal , meaning they consume half their body weight during each 20 to 30 minute feeding session . their bodies have adapted to lighten that load , and their stomach lining rapidly absorbs much of the blood’s water content and sends it to the kidneys so it can be excreted . the bats can process their meal so quickly that they may begin disposing of it before they’re even finished with it , and start urinating just a few minutes into the feeding .
blood - feeding is a risky business , particularly for a warm - blooded animal . among bats , the vampires are exceptional because they spend so much time caring for their young . young common vampires nurse for up to nine months , three months longer than flying foxes , which are many times their size , and at least six months longer than most other bats . female common vampire bats show no seasonal pattern of reproduction . but even though they may have young at any time of the year , the long period of nursing means that each female produces just one young a year .
3 . when the bats feed , they use their teeth to shear away hair or feathers from a small spot and then cut into their victim’s flesh with their sharp incisors . ( according to zoologists at chicago’s field museum , even the teeth on old , preserved bat skulls in museum collections are sharp enough to cut someone handling them carelessly . ) rather than actively suck the blood from the wound like their namesakes , the bats let the physics of capillary action do the work . they lap at the blood and specialized grooves on their lips , tongues , and / or roof or their mouths suction it up . a protein in the bats’ saliva called a plasminogen activator prevents the blood from clotting and keeps it flowing freely while they drink .
10 . vampire bats have a few different tools for finding their food . they have well - developed senses of smell and , despite bats’ reputation , keen eyesight . they’ve also got heat - seeking faces —their wrinkly , leaf shaped noses are loaded with nerves that are , in turn , loaded with proteins that are sensitive to the infrared radiation given off by warm - blooded animals . they also have finely - tuned hearing and specialized neurons that react only to the sound of breathing . they can even distinguish the breathing sounds made by different individuals , and may be able to remember the unique sonic components of an individual animal’s breathing , allowing them to return to the same reliable source of blood night after night .
2 . other bats with less grisly diets got a bad rap from european explorers in the americas . the europeans had heard stories about blood - drinking bats and encountered native people and livestock that had been bitten in the night and , without any real knowledge of the animals’ diets , began labeling different bats as vampires willy nilly , usually applying the term to bigger and / or uglier ones . bats that lived on insects or even fruit were assumed to be vampires thanks to their appearance , and the association stuck when they were scientifically described and saddled with names like vampyrum spectrum and pteropus vampyrus . meanwhile , when a naturalist finally got his hands on an actual vampire , d . rotundus , no one one believed his assertions that it drank blood , and he made no mention of it in his description .
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distribution in texas . from southern texas southward to eastern peru and brazil . known from texas on the basis of one female taken may 24 , 1967 from an abandoned railroad tunnel 19 km west of comstock , val verde county .
this species seems to be reproductively active throughout the year . pregnant females have been reported from mexico and central america in march , july , august , october , and november . the number of embryos per female is normally one , but one female captured july 8 in chiapas , mexico , contained two nearly full - term ( crown - rump length 34 mm ) embryos . the reproductive condition of the female captured in texas was not recorded .
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justification : this species is listed as least concern as it is widespread , relatively tolerant to a range of habitats , and is unlikely to be declining rapidly enough to qualify under a more threatened category .
this species ranges from southern tamaulipas ( mexico ) to colombia , venezuela , ecuador , peru , bolivia , and brazil ( except the central amazon basin ) ; a single vagrant individual has also been reported from southern texas , usa ( simmons 2005 ) . its altitudinal range goes from lowlands to 1 , 900 m ( reid 2009 ) .
this species is uncommon and local , but widespread ( emmons and feer 1997 ) . they roost either alone or in small groups of 12 or less , rarely numbering over 40 to 50 individuals ( uieda 1987 ) . in one study , d . ecaudata was observed to be more solitary and did not gather into groups when in the presence of other bats in a cave . they have a structured society in which they build strong social bonds with other bats in the colony . very rare in belize ( miller pers . comm . ) .
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