Vampire bats are the only mammals that survive exclusively on a diet of blood. The scientific word is obligate sanguivores. And yes, sometimes they bite humans. There are three species of vampire bats but we are focused on the one closest to us in the United states, the common vampire bat.
Vampire bats have excellent hearing and smell which they use to locate sleeping animals. Their native food includes wildlife peccaries, capybaras, and deer.
Nowadays with intense agriculture replacing forests they feed on domestic animals cows, pigs, and horses
They have razor-sharp front incisors for slicing skin and specialized heat-sensing nose pits to locate blood vessels. They often bite their prey in places where the blood is near the surface such as the head especially the ears and also the ankles. When feeding on sleeping humans, they tend to feed on their toes, nose and earlobes. Places that may not be covered!
Vampire bats are native to the Americas from northern Mexico southwards to central Chile and Argentina. Last week we talked about Armadillos and how their range is moving north. Same with vampire bats. Currently there are just a few random appearances in the united states but a permanent colony lives about 30 miles south of Texas. You can see on the maps I have arrows pointing to southern Texas. The red dots on the map are from a research study that tracked known colonies.
One bat we do have in the United States is the very beneficial Little Brown Bat. They eat a lot of insects! You can learn more about them in my video.
Bats have a bad reputation as evil creatures of the night. Let's talk about Little Brown bats, learn to identify them, and debunk some bat myths. We will also focus on ways to humanly evict them from your home and why you should put up a bat house.
Vampire bats are not strong flyers and dont migrate. However, they are making slow and continuous expansions northward and are expected in the United states in the next several years.
One reason they can feed undetected on larger animals is that they are not very big. They are about 3.5 inches long with a wingspan of 7 inches.
A scientist can safely hold them wearing leather gloves.
Their saliva contains special anticoagulants, including one called draculin, that prevents blood from clotting while they feed. Similar to a mosquito.
Giulia Rossi @giuliasrossi is an Animal physiologist. Her experiments have shown that vampire bats use amino acids to fuel RUNNING - a rare mode of locomotion in vampire bats ideal for stalking prey.
How cool is this. Vampire bats are the only bats that use there limbs for locomotion. This allows them to sneak up on sleeping animals.
Vampire bat running. From Giulia Rossi experiments as posted on X Nov 6 2024
They land near sleeping prey, walk or hop on the ground to get near them, make a tiny incision on their skin, and lap up the flowing blood. One concern is the transfer of pathogens. Vampire bats can carry rabies. Rabies in cattle in the United States is uncommon but not unheard of. In 2024 38 cows and steers died or were euthanized due to rabies.
In Brazil the vampire bat is the leading cause of rabies transmitted to humans. It used to be domestic dogs but vaccination programs have reduced that significantly. This can be hard for persons who live far from medical care. In 2004 there was a bad outbreak and 21 people living in the amazon basin died from rabies.
USGS is developing and testing a safe rabies vaccine for vampire bats. Vaccinating vampire bats to prevent rabies virus transmission could significantly cut livestock losses from rabies and lower the risk to humans. Culling bats is not really an option because it often results in further spread of the rabies virus. Bats disperse when their colony is disrupted and may not return to that location.
Vampire bats live in social colonies and exhibit advanced social bonds. They share food with other bats who communicate hunger. They do this by regurgitating blood for other bats who failed to hunt, making sure the group survives.
One study I read in the Journal Nature said "Some areas in the Americas may benefit from an assessment of their preparedness to deal with an expected D. rotundus range expansion." Climate change is happening and many species are expanding their ranges to survive or because they have new opportunities.
Take Away
Out of roughly 1,400 bat species worldwide, only three feed on blood. And they are native to the Americas not Transylvania. Bram Stoker read about explorers who went to central and south america and told about the blood drinkers. He combined that information with many famous myths from Eastern Europe and created his fabulous 1897 novel Dracula.