With Halloween a couple weeks away, I thought we'd check in with one of the animals that's associated with the holiday, those lovable, furry, butt-ugly bats!
OK, that's unfair. I'm sure that bats think they're beautful and that we humans are their worst nightmare. I also think they're cute, in a face-only-a-mother-could-love sort of way. Bats are nocturnal and are the world's only flying mammal. They're social animals and live in colonies. The females give birth to a single offspring each year. Bats are generally not aggressive, even when they're sick, and they are not dangerous to humans unless they have rabies. If you see a bat out and about during the day, avoid it.
There are about 1000 species of bats, of which 3 are vampires. The largest bat has a wingspan of almost 6 feet (how would you like one of those babies in your hair?!). These megabats live in warm tropical climates and tend to eat fruit and nectar. The vampires are smaller, and they live in Central and South America, thank The-Deity-of-Your-Choice for that. The smallest bats, such as the Smokey Bat, have a wingspan of around 6 inches. The Little Brown Bat is the most widely distributed and the one most often seen by people. It likes to roost in hot attics, and attic colonies can number into the thousands. Little Browns like to dine on pest insects, such as mosquitoes, gnats, wasps, and moths. They can live 30 years or more.
The legendary vampires of Europe were brooding in their drafty castles long before the discovery of vampire bats in the New World. The bats got their name from the legends, not the other way around. The White-Winged and the Hairy-Legged vampire bats prefer blood from birds and are less abundant. The Common vampire bat is the most abundant and prefers mammalian blood (cow blood is particularly popular). Vampire bats need 2 tablespoons of blood each day - the Common vampire bat cannot go 2 nights without food, otherwise it starves to death.
Not all bats hang upside down - some prefer roosting in horizontal crevices instead - but the vast majority do hang upside down when they sleep. Their body weight 'locks' their feet into position to keep them in place. There are a couple reasons for this unique behaviour. Unlike birds, bats can't get themselves airborne from the ground. Their wings don't produce enough lift to take off from a dead stop, and their hind legs are too weak to allow them to build up the necessary takeoff speed. Instead, they 'fall' into flight. By sleeping upside down in a high location, they are ready to take off if they need to. Hanging upside down is also a great way to hide from undesirables. During the day, bats roost where few predators can reach. They also don't have to compete for their roosting spots, since other animals prefer to sleep upright.
One of the many myths about bats is that they can't see well, hence the adage 'blind as a bat'. As it turns out, bats see just fine and some see better than humans do, but since they're nocturnal they can use some assistance in flitting about. This assistance is called echolocation, which is a kind of sonar. The bats make high-pitched sounds that bounce off objects and return as echoes. The echoes allow them to tell the difference between a building, a tree, and dinner.
Echolocation perhaps would have been useful to Douglas 'Wrong-Way' Corrigan, an American aviator who got his nickname because of a supposed navigational error. In 1938, Corrigan 'mistakenly' flew from New York to Ireland - when he was supposed to be flying from New York to California - because he misread his compass.
What many people don't know is that Corrigan had repeatedly tried to get permission from the federal government to fly from the United States to Ireland, only to be denied each time. On July 17, Corrigan took off from Floyd Bennett Field in thick fog and headed east to avoid some buildings at the western edge of the field. Airport officials believed Corrigan would turn his plane around and head west once he had cleared the airport's airspace. Instead he kept flying east. Corrigan insisted that visibility was so poor that he could only fly by using his compass, which showed that he was heading west. He said he had realized his 'mistake' about 26 hours later when he finally dropped below the clouds and discovered he was over water. A short time later he arrived in Ireland. Despite questioning by the authorities at the time and by newspaper reporters throughout his life, Corrigan never admitted the ruse.
Speaking of ending up somewhere other than where you'd intended -
Monday 13 October was Columbus Day in the United States, marking the anniversary of Christopher Columbus' first landing in the New World. In an era when many still believed the Earth was flat, he'd set out to prove you could reach India by sailing west. Columbus thought he was in India - and believed to the day he died that he had reached Asia - when early on the morning of 12 October 1492 he spotted land. In fact he was actually in the Bahamas.
Of course Columbus wasn't the first to reach the Americas. He wasn't even the first European - the Vikings had settled Iceland and Greenland roughly 500 years earlier. And the aboriginal peoples of the New World had been living there for thousands of years while the Europeans thought that 'there be dragons'.
To confuse matters further, the newly-discovered lands were named not for Columbus but for Amerigo Vespucci1, a less well-known explorer. His name was given to the Americas by map maker Martin Waldseemüller2.
In 1507 Waldseemüller was working on a world map, and he had read accounts of Vespucci's travels. In honour of Vespucci's discoveries, Waldseemüller printed a map with the name 'America' on the southern continent of the New World. By 1513 Waldseemüller had changed his mind about the name, but copies of his earlier map had been widely distributed and so 'America' it was.
This is why we're not called Columbians, or Cabotians3, or Erik-the-Red-ians. The moral of this story is: think before you publish.
Did You Know?
- It has long been thought that American Indians are descendants of Asians who had crossed from Siberia into North America via Beringia (which is now under the waters of the Bering Strait off Alaska). But during the past decade or so, research in South America suggests that it was populated before the northern continent. For a look at the evidence, see The First Americans: Were They Australians?.
- Christopher Columbus is not a popular figure among many American Indians. They view him as a symbol of imperialism who brought disease and death to the indigenous population of the Americas. For two opposing views on Columbus' legacy, check out Why Autonomous AIM Opposes Columbus Day and Columbus Day Parades and Did Christopher Columbus 'Discover' America?. The BBC presented a brief news story on the subject titled Columbus 'sparked a genocide'.
The Edited Guide has a lot to say about bats. Check out these articles:
- Bats eat mosquitoes but they don't put a significant dent in the mosquito population, according to Count Zero who wrote an excellent article on Why Mosquitoes Must Die.
- How a Bat's Sensor Works describes how bats use echolocation to find their food and avoid running into things.
- Wildlife Gardening - Mammals and Birds tells you how to attract various animals, including bats, to your garden.
- Seabird Guano and Bat Dung ('nuf said)