Bats, belonging to the order Chiroptera, are the only mammals that can fly. Capable of sustained flight, bats flap their long spread-out digits covered with a thin membranous structure (patagium) for flying. They are typically more maneuverable than birds, and this ability, combined with their capability to navigate using an acoustic orientation method, has made them a highly populous order.
There are approximately 1,200 species of bats described by zoologists and naturalists. These species are categorized into two suborders, Microchiroptera or microbats, and Megachiroptera or megabats. Some of the commonly found bat species are given below:
Size: Their size varies depending on the species. Kitti’s hog-nosed bat is the smallest bat species with a length of 1.14-1.34 in (29-34 mm) and a wingspan of 5.91 in (15 cm). The golden-crowned flying fox is one of the largest bats with a forearm length of 8.5 in (215 mm) and a wingspan of 4.9-5.6 ft (1.5-1.7 m).
Weight: The smallest Kitti’s hog-nosed bat weighs about 0.07-0.09 oz (2-2.6 g) while the giant golden-crowned flying fox has an average weight of 4 lb (1.6 kg).
Color: They are usually black or brown, but may have orange, white, red, or gray coloration. Certain types like the spotted bats possess white facial markings.
Head: The shape of their head varies by species with the megabats having larger eye sockets, smaller ears, and longer snouts, giving them a dog-like appearance. Microbat species like vampire bats possess reduced snouts for accommodating large canines and incisors.
Dentition: Insect-eating bats possess 38 teeth, while blood-sucking vampire bats have 20. Bats feeding on hard-shelled insects are characterized by longer canines and robust lower jaws. Nectar-feeding bats have long canines and reduced cheek-teeth, while fruit-eating bats have cheek-teeth cusps adapted for crushing.
Wings: Bats have much thinner wings, consisting of more bones as compared to the wings of birds. The wing surface has touch-sensitive receptors, while the patagium or wing membrane contains elastic fibers, nerves, blood vessels, connective tissues, and muscles.
Aside from the Arctic, the Antarctic, and some isolated oceanic islands, bats are distributed throughout the world, being abundant in the tropics. About 45 bat species are found in the US, while approximately 100 species exist in West Africa.
Bats can live in diverse habitats depending on the season, ranging from deserts to mountains and seasides. They need suitable roosts, which are found in crevices, foliage, hollows, and human-made structures. Megabats typically roost in trees.
In the wild, the average lifespan of bats is less than 20 years. Six species, including the Indian flying fox, greater horseshoe bat, lesser mouse-eared bat, Brandt’s bat, little brown bat, and brown long-eared bat, have been found to live for more than 30 years in the wild. In 2006, scientists found a tiny bat in Siberia, which was documented to be the longest-living, having survived for 41 years.
Most microbats are insectivores and feed on flies, mosquitoes, moths, beetles, crickets, grasshoppers, bees, termites, wasps, caddisflies, and mayflies. Megabats are usually frugivores that eat fruits, pollens, and nectar. Insectivorous bats consume more than 120% of their weight, whereas frugivorous bats eat over two times their body weight. The large amounts of food consumed make up for the energy lost through a flight.
Some bat species, such as the fringe-lipped bat hunts frogs, greater noctule bat feeds upon birds, and greater bulldog bat eats fish. Several species like the common hairy-legged and white-winged vampire bats feed on the blood of mammals and birds.
Bats may have polygynous (males have multiple female partners), monogamous (males have one mate at a time), and promiscuous (both males and females have multiple partners) mating systems depending on the species. Pipistrelle, vampire, and noctule bats are polygynous, while the little brown and Mexican free-tailed bats are promiscuous, and the spectral and yellow-winged bats are monogamous.
In temperate regions, bats mate during late summer or early autumn, while tropical bats copulate in the dry season. To prevent other males from mating, males leave behind a vaginal plug after copulation. Males of hibernating species mate with females in a dormant state.
Females of some bat species exhibit delayed fertilization, meaning the sperm is deposited in their reproductive tract, and fertilization takes place in spring several months after mating. Other species have delayed implantation, which means that the egg remains free in the mother’s reproductive tract, and the birth of young is delayed until conditions become favorable to care for the offspring.
Temperate-living bats in the northern and southern hemispheres give birth in May-June and November-December, respectively, while tropical species produce their offspring at the start of the rainy season. Females usually give birth to one offspring per litter. The pup weighs about 40 percent of its mother’s weight at birth. Young bats are weaned in about 80 days.
In countries across Asia, Africa, and the Pacific, bats are eaten or hunted for food. Pressure damage caused by wind turbines also kills bats. Organizations like Bat Conservation International strive towards increasing awareness regarding the ecological roles played and the threats faced by bats. In the UK, the Wildlife and Countryside Acts protect all bat species, which means harming them in any way is a punishable offense. The Wildlife Protection Ordinance 1998 has also been implemented in Sarawak, Malaysia, to protect all bats from being hunted or eaten.
1. Are bats blind?
Although no bats are blind, most microbat species have small and poorly-developed eyes, leading to poor clarity. They can detect low levels of light, while some microbats can even detect UV light. Megabats, on the other hand, have good eyesight that is adapted to daylight and night visions.
2. Do bats hibernate?
Some species, including Indiana bat, eastern red bat, silver-haired bat, and little brown bat hibernate in places like mines, caves, and rock crevices with ideal humidity and temperature.
3. Are bats rodents?
No. Bats are not even related to rodents.
4. Are bats dangerous?
Some bats can be harmful to humans since they may carry many infectious bacteria and viruses, including rabies, Nipah, Ebola, and coronaviruses.
5. Do bats lay eggs?
No
6. What is a baby bat called?
A pup
7. What is a group of bats called?
A colony
8. What predators may eat bats?
Birds of prey like hawks, owls, and falcons, alongside terrestrial predators such as cats and snakes, may hunt and feed on bats.
