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What the sources say

Common Vampire BatDesmodus rotundus

Every figure, record and mechanism on the Common Vampire Bat profile was written from a source, and this is the working table behind it: 58 claims checked word for word against these sources. The left column is what the page says. The right column is the source's own words, copied, not paraphrased; a ... marks a cut and[brackets] an insertion. Open any source and check it yourself.

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Source
01

Animal Diversity Web, University of Michigan

Desmodus rotundus (vampire bat). Animal Diversity Web, University of Michigan.

The page sayscrosses the ground on all fours to reach it
The source saysDesmodus rotundus can walk, run, and hop quadrupedally along the groundNote: tagline; 'on all fours' = quadrupedally
The page saysIt weighs 15 to 50 grams
The source saysRange mass 15 to 50 g
The page saysa wingspan of 35 to 40 centimeters
The source saysRange wingspan 350 to 400 mmNote: converted mm to cm
The page saysa body 7 to 9 centimeters long
The source saysRange length 70 to 90 mmNote: converted mm to cm
The page saysand it eats nothing else
The source saysDesmodus rotundus feeds exclusively on the blood of other vertebrates
The page saysThe bat usually lands near its host and walks or hops up to it
The source saysUsually when a bat approaches its prey, it does not land directly on the animal, but rather, lands nearby and walks or hops up to the unsuspecting victim.
The page saysthen makes a 3-millimeter incision in the skin
The source saysthe bat makes a 3mm incision in the skin and laps up the blood from the wound
The page saysThe bite is relatively painless and rarely wakes a sleeping animal
The source saysThe bite is relatively painless and rarely wakes a sleeping victim.
The page saysThe common vampire bat walks, hops and runs
The source saysDesmodus rotundus can walk, run, and hop quadrupedally along the ground
The page saysBlood only
The source saysDesmodus rotundus feeds exclusively on the blood of other vertebratesNote: stats.diet
The page saysdangerLevel: Medium
The source saysA bite from Desmodus rotundus can cause infections and transmit diseases carried by the bat.Note: #670: tier as capability; a 15 to 50 g bat whose bite 'is relatively painless and rarely wakes a sleeping victim'. The harm is infection and rabies, not the wound
The page saystags: echolocation
The source saysVampire bats use echolocation and vision to navigate and find prey.Note: #670

Source
02

Bat Conservation International

Common Vampire Bat. Bat Conservation International.

The page saysIt ranges through warm tropical and subtropical country from southern Mexico down to northern Argentina and Chile
The source sayscommon vampire bats are restricted to warm climates, and live in tropical and subtropical areas ranging from southern Mexico to northern parts of Argentina and Chile
The page saysroosting alongside tens to thousands of others in caves, tree hollows, old mine shafts and abandoned buildings
The source saysLiving in colonies ranging from tens to thousands of individuals, common vampire bats roost in tree hollows and moderately lit caves as well as human-made structures such as old wells, mine shafts, and abandoned buildings.
The page saysIt feeds mainly on mammal blood, from wild tapirs to livestock such as cattle, horses and pigs
The source sayscommon vampire bats feed primarily on mammal blood ranging from large wild mammals such as tapirs to common livestock such as cows, horses, and pigs
The page saysProteins in its saliva keep the wound from clotting while it laps up the blood, rather than sucking it
The source saysThey don't actually suck the blood from their prey, but instead lap the blood from the wound while special proteins in their saliva prevent the wound from clotting.
The page saysOn the ground, it can run at up to 2.5 miles an hour
The source saysUsing a bounding-type movement, they can run up to 2.5 miles an hour.
The page saysCaves, tree hollows and old mine shafts in warm regions from southern Mexico to northern Argentina and Chile
The source sayscommon vampire bats are restricted to warm climates, and live in tropical and subtropical areas ranging from southern Mexico to northern parts of Argentina and Chile ... roost in tree hollows and moderately lit caves as well as human-made structures such as old wells, mine shafts, and abandoned buildingsNote: stats.habitat
The page saysmainly from mammals such as cattle, horses, pigs and wild tapirs
The source sayscommon vampire bats feed primarily on mammal blood ranging from large wild mammals such as tapirs to common livestock such as cows, horses, and pigsNote: stats.diet
The page saysAnticoagulant saliva
The source saysThey don't actually suck the blood from their prey, but instead lap the blood from the wound while special proteins in their saliva prevent the wound from clotting.Note: stats.superpower
The page saysSpecial proteins in its saliva keep the wound from clotting while the bat laps up the blood. It doesn't suck blood at all
The source saysThey don't actually suck the blood from their prey, but instead lap the blood from the wound while special proteins in their saliva prevent the wound from clotting.
The page saysIt laps it from a small cut made with its sharp front teeth
The source saysTheir front teeth (incisors) are sharp and pointed, and are used to make small cuts in their prey.

Source
03

AnAge: The Animal Ageing and Longevity Database, Human Ageing Genomic Resources

AnAge entry for Desmodus rotundus. AnAge: The Animal Ageing and Longevity Database, Human Ageing Genomic Resources.

The page saysIn captivity, one vampire bat lived to 29.2 years old
The source saysMaximum longevity 29.2 years (captivity)

Source
04

Barquez et al. 2015

Barquez et al. (2015). Desmodus rotundus. The IUCN Red List of Threatened Species 2015: e.T6510A21979045.

The page saysLeast Concern
The source saysIUCN Red List category: Least Concern (LC).Note: stats.conservationStatus

Source
05

Zepeda Mendoza et al. 2018

Zepeda Mendoza et al. (2018). Hologenomic adaptations underlying the evolution of sanguivory in the common vampire bat. Nature Ecology & Evolution.

The page saysOne of only three mammals that must feed on blood
The source saysone of the only three obligate blood-feeding (sanguivorous) mammalsNote: tagline; 'must feed on' = obligate
The page saysit is one of only three mammals that must feed on blood, a habit called sanguivory
The source saysone of the only three obligate blood-feeding (sanguivorous) mammals
The page saysOne of Only Three Blood-Feeding Mammals
The source saysone of the only three obligate blood-feeding (sanguivorous) mammalsNote: heading

Source
06

Gracheva et al. 2011

Gracheva et al. (2011). Ganglion-specific splicing of TRPV1 underlies infrared sensation in vampire bats. Nature.

The page saysit finds warm prey through heat-sensing pits on its face
The source saysthe ability to detect infrared radiation as a means of locating hotspots on warm-blooded prey ... infrared signals are detected by trigeminal nerve fibres that innervate specialized pit organs on the animal's faceNote: tagline
The page saysFinding a meal starts with heat. The bat detects infrared radiation to locate hotspots on warm-blooded prey
The source saysthe ability to detect infrared radiation as a means of locating hotspots on warm-blooded prey
The page saysthrough nerve fibers running to pit organs on its face
The source saysinfrared signals are detected by trigeminal nerve fibres that innervate specialized pit organs on the animal's face
The page saysAmong vertebrates, only vampire bats, pit vipers, boas and pythons can sense infrared
The source saysAmong vertebrates, only vampire bats, boas, pythons and pit vipers are capable of detecting infrared radiation.
The page saysA protein called TRPV1, which still detects painful heat elsewhere in the bat's body
The source saysThese splicing events occur exclusively in trigeminal ganglia, and not in dorsal root ganglia, thereby maintaining a role for TRPV1 as a detector of noxious heat in somatic afferents.Note: 'elsewhere in the bat's body' = somatic afferents from dorsal root ganglia
The page sayshas its trigger point lowered to about 30 degrees Celsius in these facial nerves
The source saysvampire bats tune a channel that is already heat-sensitive, TRPV1, by lowering its thermal activation threshold to about 30 °C ... These splicing events occur exclusively in trigeminal ganglia
The page saysinfrared-sensing pits on its face
The source saysinfrared signals are detected by trigeminal nerve fibres that innervate specialized pit organs on the animal's faceNote: stats.superpower
The page saysIt has pit organs on its face, wired to nerves that pick up infrared radiation
The source saysinfrared signals are detected by trigeminal nerve fibres that innervate specialized pit organs on the animal's face
The page saysit uses them to locate hotspots on warm-blooded prey
The source saysthe ability to detect infrared radiation as a means of locating hotspots on warm-blooded prey
The page saysApart from vampire bats, only boas, pythons and pit vipers among vertebrates can detect infrared
The source saysAmong vertebrates, only vampire bats, boas, pythons and pit vipers are capable of detecting infrared radiation.
The page saysfinds warm-blooded prey by detecting infrared radiation
The source saysthe ability to detect infrared radiation as a means of locating hotspots on warm-blooded preyNote: vibe.reason (women artists, round 2)
The page saysthrough pit organs on its face
The source saysinfrared signals are detected by trigeminal nerve fibres that innervate specialized pit organs on the animal's faceNote: vibe.reason (women artists, round 2)

Source
07

Schutt et al. 1997

Schutt et al. (1997). The Dynamics of Flight-Initiating Jumps in the Common Vampire Bat Desmodus Rotundus. Journal of Experimental Biology.

The page saysIts complex moves on the ground, which include vertical jumps that launch it into flight, are tied to its unusual way of feeding
The source saysexhibits complex and variable terrestrial movements that include flight-initiating vertical jumps. This ability is unique among bats and is related to their unusual feeding behavior.Note: 'unique among bats' deliberately dropped: dated 1997, and Riskin 2005 treats vampire running as one independent origin
The page saysIn a flight-starting jump, the push against the ground can peak at 9.5 times the bat's own body weight within about 30 milliseconds
The source saysPeak vertical force can reach 9.5 times body weight in approximately 30 ms.
The page sayslaunching it at an average of about 2.4 meters a second
The source saysmean take-off velocity of 2.38+/-0.24 m s-1Note: 2.38 rounded to 2.4

Source
08

Riskin & Hermanson 2005

Riskin & Hermanson (2005). Independent evolution of running in vampire bats. Nature.

The page saysBats have become so specialized for flight that they have almost lost the ability to move on land at all. Vampire bats are an important exception
The source saysbats have become so specialized for flight that they have almost lost the ability to manoeuvre on land at all. Vampire bats, which sneak up on their prey along the ground, are an important exception.
The page saysits run is a bounding gait powered by its wings instead of its hind legs
The source sayscommon vampire bats can also run by using a unique bounding gait, in which the forelimbs instead of the hindlimbs are recruited for force production as the wings are much more powerful than the legs
The page saysan ability that seems to have evolved independently within the bat lineage
The source saysThis ability to run seems to have evolved independently within the bat lineage.
The page saysa bounding run on land powered by its wings
The source sayscommon vampire bats can also run by using a unique bounding gait, in which the forelimbs instead of the hindlimbs are recruited for force production as the wings are much more powerful than the legsNote: stats.superpower

Source
09

Carter & Wilkinson 2013

Carter & Wilkinson (2013). Food sharing in vampire bats: reciprocal help predicts donations more than relatedness or harassment. Proceedings of the Royal Society B: Biological Sciences.

The page saysCommon vampire bats often regurgitate food to roost-mates that fail to feed
The source saysCommon vampire bats often regurgitate food to roost-mates that fail to feed.
The page saysA 2013 study that fasted 20 vampire bats one at a time
The source sayswe individually fasted 20 vampire bats (Desmodus rotundus) and induced food sharing on 48 days
The page saysfound that this sharing is not explained by kinship alone
The source saysthese findings support the hypothesis that food sharing in vampire bats provides mutual direct fitness benefits, and is not explained solely by kin selection or harassment
The page saysHow much food a bat had received from a particular partner was the best predictor of how much it gave back to that bat, 8.5 times more important than relatedness
The source saysFood received was the best predictor of food given across dyads, and 8.5 times more important than relatedness.
The page saysDonors also started the sharing more often than the hungry bats did, which does not fit the idea that they were pestered into it
The source saysdonors initiated food sharing more often than recipients, which is inconsistent with harassment
The page saysMostly by paying back help
The source saysFood received was the best predictor of food given across dyads, and 8.5 times more important than relatedness.
The page saysWhen researchers fasted bats one at a time
The source sayswe individually fasted 20 vampire bats (Desmodus rotundus) and induced food sharing on 48 days
The page saysthe amount a bat had been fed by a partner predicted what it gave that partner better than anything else, and mattered 8.5 times more than kinship
The source saysFood received was the best predictor of food given across dyads, and 8.5 times more important than relatedness.
The page saysDonors also made the first move more often than the hungry bats, which does not fit bullying
The source saysdonors initiated food sharing more often than recipients, which is inconsistent with harassment

Source
10

Wilkinson 1990

Wilkinson (1990). Food Sharing in Vampire Bats. Scientific American.

The page saysTwo nights without a blood meal and a vampire bat starves to death, biologist Gerald Wilkinson wrote in 1990, unless it can get a roostmate to share
The source saysTwo nights without a blood meal and a vampire bat starves to death-unless it can solicit food from a roostmateNote: attributed and dated; 'get a roostmate to share' = solicit food from a roostmate
The page saysTwo nights without a blood meal and a vampire bat starves to death, unless it can get a roostmate to share, Gerald Wilkinson wrote in 1990
The source saysTwo nights without a blood meal and a vampire bat starves to death-unless it can solicit food from a roostmate
The page saysHe described a buddy system that keeps food distribution among the bats fair
The source saysA buddy system ensures that food distribution among the bats is equitable

How the table was made: a writer drafted the profile from these sources and logged each claim with its quote, a reviewer with nothing but this table checked every sentence said no more than its quote, and a script confirmed each quote appears word for word in the source. The method is in the site'sAbout page.