Bats' ability to fly is one of their most amazing adaptations. Their hand has evolved into a wing covered with a stretchy, leathery, and very durable membrane. The word Chiroptera, which is the name of their Order, literally translates into "handwing".

This is strikingly clear when viewing the photo on the left. The bats fingers are extremely large and run from wrist to the bottom of the wings while the thumb sticks straight up and is not covered by the leathery membrane that covers the other four fingers.

Another incredible adaptation is their ability to navigate by using echolocation. Echolocation works the way a sonar radar would. Bats emit high frequency sounds. The sound in turn bounces off their surrounding environment and returns to them. The sounds are emitted by way of the bats mouth and nose and may travel at approximately 340 meters per second! The bats then analyze the time it takes for the echoes to return to them and are able to tell how far away an object is. This gives the bats a perfect picture of their surroundings even on the darkest nights.

Insect eating bats play a crucial role in controlling insect populations. Insectivore bats consume a huge numbers of insects that could potentially cost farmers and foresters billions of dollars and spread disease among humans. It is estimated that just the 20 million Brazilian Free-tailed Bats that inhabit Bracken Cave, in Texas, devour some 225 metric tons of insects every night!! On average a family car weighs about 1.5 metric tons, meaning that this bat colony alone consumes approximately the weight of 150 family cars in insects per night, a truly a staggering feat! Little Brown Bats often eat mosquitoes and can catch up to 1,200 small insects per hour. A typical Big Brown Bat colony can consume enough Cucumber Beetles to avoid tens of millions of the beetle's larvae depleting a farmer's crop.  Imagine a world without bats. The guano produced by these insectivore bats is also a valuable fertilizer.

It is estimated that bats are responsible for the pollination and seed dispersal of hundreds, possibly thousands, of trees and plants. Plants and trees like Ficus, Cecropia, Solanum, and Piper depend on bats for seed dispersal. Scientists estimate that Balsa Trees (Ochroma pyramidale) rely solely on nectar and pollen eating bats for pollination.

Fruit eating bats play a key role in regenerating forests. Unlike birds, who normally defecate while perching, bats tend to defecate in flight. This means that seeds will fall to the ground and develop far from the shade of the parent tree, perhaps in an open field.

Unfortunately, bat populations are declining worldwide. The causes are the usual suspects: global warming, destruction of habitat, human persecution, pollution and the use of pesticides. Pesticides are especially harmful. They are used on the insects that are consumed by bats, and end up poisoning the bats. This has led to serious declines in some areas.

Another budding danger to bats is the growing number of wind turbines being erected to harvest electricity. It seems that bats, unlike the birds that hit them by accident, may be attracted to the turbines. One study in West Virginia in a site with 44 turbines documented between 1,300 and 2000 bats killed during a six week period.

But perhaps the most troubling development for bats in the last few years is White-nose Syndrome. This mysterious disease has killed tens, perhaps hundreds of thousands of bats in North America. Up to 95 percent of the population of infected bat colonies are being wiped out throughout hibernation caves in New York, Vermont, Massachusetts, Connecticut, and possibly Pennsylvania. They call it White-nose Syndrome because infected bats exhibit a white fungus on their noses, although scientists don't think the fungus is the cause of the problem.

The scariest thing is that scientists have no idea what is causing this bat epidemic or how to stop it. Infected bats are leaving their hibernation caves earlier than normal in a severe state of emaciation and dehydration. Many also have wing injuries, apparently acquired during their hibernation, and the bulk of the bats belonging to infected colonies are usually discovered lying dead on the cave floors.

We encourage all of our readers to visit the Bat Conservation International Website at http://www.batcon.org/home/default.asp and find out what you can do to help save these remarkable animals. It is time we realized how important bats really are to our planet and take the necessary steps to protect these wonderful creatures.

The following pages are dedicated to four of the most commonly seen bats on the Osa Peninsula: Tent-making Bats, Greater Bulldog Fishing Bats, White-lined Bats, and Brazilian Long-nosed Bats. All bats appearing on these web pages are live specimens photographed in the wild. The two photographs of bats being handled, pictured above, were taken at Tirimbina Biological Reserve during a bat tour.