Vampire Bat Classification and Evolution
The vampire bat is a small species of bat, native to the tropics of Central and South America. There are three recognised sub-species of vampire bat, all of which are in a genus of their own despite their obvious similarities. The common vampire bat, the hairy-legged vampire bat and the white-winged vampire bat are all closely related and share the same unique feeding habits, as they are the only known mammals that feed entirely on blood. Over time, vampire bats have perfectly adapted to the consumption of their only food source, with a leaf-like heat sensor on the end of their nose which detects where the warm blood is flowing closest to the skin.
Vampire Bat Anatomy and Appearance
The vampire bat is quite a small animal, with it's body rarely growing larger than the size of a human thumb. It's wings are long, finger-like bones that are covered in a thin layer of skin, with a thumb claw that pokes out of the front and is used for grip when clambering about on their host. Vampire bats have dark brown to grey furry bodies with a lighter underside, and strong limbs which enable them to crawl about on the ground with ease. As with other bats, vampirebats use echolocation in order to determine their surroundings. When flying, they produce high-pitched sounds that bounce of the objects in the area, and it is this bounced-back sound that allows the bat to figure out where things are around them (it is so high-pitched that it cannot be heard by people).
Vampire Bat Distribution and Habitat
The vampire bat is found throughout the South American continent from Mexico to the tip of Argentina. Vampire bats are found in both tropical and subtropical regions and can adapt to living in both humid and dry climates. Many bats are nocturnal and the vampire bat is no exception, spending the daylight hours roosting in hollow trees, caves, mines and even derelict buildings in colonies that can be more than 1,000 strong. Although other bat species are known to nest in the same places as the vampire bats, it is thought that the separate species tend to keep their distance from one another to avoid conflict.
Vampire Bat Behaviour and Lifestyle
After sleeping upside in the darkness all day, vampire bats emerge when the moon appears in order 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 bats fly about a meter above ground in search of a warm-blooded animal, and once found, they land close to it. The vampire bat then crawls up to it's generally sleeping victim, before biting it and feeding on the flowing blood. Vampire bats tend to be solitary hunters but roost together in colonies that usually contain around 100 individuals, and contain alpha males and their harems of around 6 females, and their young.
Vampire Bat Reproduction and Life Cycles
Vampire bats mate all year round and are known to have a fairly long gestation period in comparison to other species of small tropical bat. After between 3 and 4 months, the female vampire bat gives birth to a single baby which she cares for until it is weaned at between 3 and 5 months of age (those bat babies born in captivity are weaned noticeably later, when they are 9 months old). As with other mammals, the young vampire bats feed on their mother's milk until they are old enough to consume an adult diet, and will not reach their full adult weight for roughly a year. Female vampire bats do appear to be very caring mothers, known to care for and adopt young orphans in the colony. Vampire bats can live for up to 12 years in the wild, although captive individuals have been known to nearly reach the age of 20.
Vampire Bat Diet and Prey
Vampire bats use echolocation, sound and smell in order to find their prey, which can be up to 10,000 times the size of this tiny predator, and it is because of this that vampire bats have evolved to taking some precautions when feeding. Firstly, the never land on their prey 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 bat then bites it's host, immediately jumping back in case the animal wakes up. Contrary to popular belief, vampire bats 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 host from feeling anything.
Vampire Bat Predators and Threats
Despite being a unique and versatile predator itself, the vampire bat is still prey to other animals, that can hunt the bat in the air when it comes out to hunt at night. Large, sharp-eyed birds of prey such as hawks and eagles are the most common predators of the vampire bat, along with snakes that hunt the bats in their dark caverns while they are sleeping during the day. Humans though are one of their biggest threats, mainly farmers that are known to poison the batsthat commonly feed on their livestock. These poisons (known as vampiricides) are specially designed to spread throughout the whole colony through social grooming, killing hundreds of individuals at a time.
Vampire Bat Interesting Facts and Features
Vampire bats feed exclusively on the blood of warm-blooded animals, drinking up to a teaspoon (25ml) of blood per 30 minute feed. Once having feasted on their host however, the bats are then so bloated that they can barely fly with their weight almost having doubled. It is said that in just one year, an average sized vampire bat colony can drink the blood of 25 cows, but their metabolism 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 diet, apart from the set of razor-sharp incisors at the front used for biting flesh.
Vampire Bat Relationship with Humans
The vampire bat is one of the only bat species that is considered a pest by humans. Farmers particularly have a very strained relationship with these flyingmammals, that feed on their sleeping cows under the cover of night. Even though the amount of blood consumed by the bat is minimal and does not harm theanimal, 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 bat individuals, and a number of other species. Fictional tales of vampire bats and their overly-exaggerated feeding habits has also increased the superstition about them.
Vampire Bat Conservation Status and Life Today
All three subspecies of vampire bat have been listed as being of Least Concern of becoming extinct in the wild in the immediate future, due to the fact that they are widespread and feed on a variety of warm-blooded animals. Deforestation of their natural habitats along with persistent human 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 thebat'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.
