Many of you will have seen bats flying around at night as you sat outside having a quiet drink by the pool. Bats are mammals in the order Chiroptera. The forelimbs of bats are webbed and developed as wings, making them the only mammals naturally capable of true and sustained flight. By contrast, other mammals said to fly, such as flying squirrels, glide rather than fly, and only for short distances. Bats do not flap their entire forelimbs, like birds, but instead flap spread out digits, which are very long and covered with a thin membrane. Although the eyes of most microbats are small and poorly developed, leading to poor visual acuity, none of them are blind. Vision is used to navigate microbats, especially for long distances when beyond the range of echolocation. It has even been discovered that some species are able to detect ultraviolet light. They also have a high quality sense of smell and hearing. Bats hunt at night to avoid competition from birds and they travel large distances of up to 800 km in their search for food.
The most common question about bats is why they hang upside down. The answer is quite simple, when you understand a little about what a bat is.
As a member of the order Chiroptera, or hand-wing, the bat has delicate and amazing wing structure consisting of two layers of skin over light bones. Their ‘toes’, along with the hooked claws at the end of four jointed fingers and a ‘thumb’ on each wing, help them to crawl along a wall or tree trunk, but the bat is the only mammal to rely mainly on wings for locomotion. As a result, their leg structure does not have the strength to keep them in an upright position for very long. They are, however, able to grip a branch, and in order to take the weight off their feet, they hang upside down. Even their young, born live, and one per year, are forced to hang the same way, to feed from the pectoral breasts.
There are about 1,100 bat species worldwide. About 70% of bats are insectivores and most of the rest are frugivores. A few species are carnivorous, including the frog-eating bats. Frog-eating bats identify edible frogs from poisonous ones by listening to the mating calls of male frogs. Whether it is innate intelligence, or simply experience, bats are able to tell the call of a poisonous frog from that of one that is edible. Frogs counter this by hiding and using short, difficult to locate calls. When the bat wants to feed, it takes off into the night, using an echo-sound system that bounces signals off objects as small as a bug, to locate them. The primary diet of bats, are night insects, which they consume in great numbers, even though they can’t ‘see’ them.
Bats are present throughout most of the world and perform vital ecological roles, pollinating flowers and dispersing the seeds of fruit. Many tropical plants depend entirely on bats for the distribution of their seeds. Most microbats are nocturnal and are active at twilight. A large portion of bats migrate hundreds of kilometers to winter hibernation dens] and some pass into torpor in cold weather, rousing and feed when warm weather allows for insects to be active. Others retreat to caves for winter and hibernate for six months. Bats rarely fly in rain as the rain interferes with their echo location, and they are unable to locate their food.
Most bats have a breeding season, which is in the spring for species living in a temperate climate. Bats may have one to three litters in a season, depending on the species and on environmental conditions such as the availability of food and roost sites. Females generally have one offspring at a time. This is maybe a result of the mother’s need to fly to feed while pregnant. Female bats nurse their youngster until it has grown to nearly adult size. This is because a young bat cannot forage on its own until its wings are fully developed.
Contrary to popular belief, bats don’t want to bite your neck! Of the over 1,000 species, only three actually live on blood and they apparently have no taste for humans.
The bat is sometimes used as a heraldic symbol. The coats of arms of certain cities in eastern Spain, like Valencia, Palma de Mallorca and Fraga have the bat over the shield. Formerly the Barcelona city coat of arms also had a bat crowning it, but the bat has been removed in the present-day versions.
The heraldic use of the bat in Valencia, Catalonia and the Balearic Islands has its origins in a winged dragon, which featured in King James I of Aragon’s helmet. This is the most widely accepted theory, although there is also a legend that says that due to the intervention of a bat, King James was able to win a crucial battle against the Saracens that allowed him to win Valencia for his kingdom.
The use of the bat as a heraldic symbol is prevalent in the territories of the former Crown of Aragon and it is little used elsewhere, however, it can be found in a few places such as in the coats of arms of the city of Albacete.
Certain Spanish soccer clubs including Valencia CF and FC Barcelona use bats in their badges. The Burgee of the Royal Valencia Yacht Club displays a bat on a golden field in its center.