Earth, wind and fire: the fruit bats of Montserrat have had to contend with most of nature's torments

Natural History, July-August, 2003 by Scott C. Pedersen

It was July 1997, and a long night, which had followed a long day, was finally nearing its end. A volcano was grumbling, and rain had just begun ... again. My right boot was quickly filling with water and sinking deeper into cold mud, and a large, muscular pig-nosed fruit bat (Brachyphylla cavernarum) had latched its mouth firmly onto the flesh of my thumb. I had been careless taking the bat out of one of my mist-nets--a finely spun net--and the bat was impressing this fact on me.

For once, though, the truth didn't hurt. Typically a bite from this species would have left me trying to stifle a string of colorful expletives, but this animal didn't have a tooth left in its head. The rather soggy-looking, unfortunate animal was also just about entirely bald. Things were getting a bit surreal: a hairless, toothless bat was gumming my thumb as I stood on the flanks of an active volcano; large, glowing rocks were rolling down the slope in my general direction; and now the mud was beginning to swallow my other boot. I suddenly felt the need for a very cold beer.

The pathetic bat and I were in the British crown colony of Montserrat, a rugged, forty-square-mile tropical island in the northern Lesser Antilles, some 250 miles southeast of Puerto Rico. Although Columbus never bothered to land on the island, he named it, in 1493, after a Spanish monastery near Barcelona, famous for its wooden statue of the Virgin and child. The British colonized the island in 1632, and a succession of sugar cane, cotton, and lime plantations dominated the local economy.

Montserrat lies in the middle of the Atlantic Ocean's "hurricane belt" a highway of sorts for the storms heading north from the Tropics. At least thirty hurricanes have battered Montserrat in the past 360 years; twelve have been severe, and Hurricane Hugo, in 1989, was the most destructive in recent history. Montserrat also lies near the convergence of the North American and Caribbean tectonic plates, so if the hurricanes don't get you, the earthquakes and volcanic eruptions might. Major temblors hit the island in three periods: 1898-1900, 1933-36, and 1966-67. Seismic activity in the Soufriere Hills volcano, beginning in 1992, resulted in an explosive eruption in July 1995, followed by a series of pyroclastic mudflows that destroyed and buried most of Plymouth, the island's capital, by 1998. Subsequent eruptions have reduced much of the southern half of the island to a wasteland. (Although the volcano's activity has decreased for the moment, it is too soon to tell whether the current cycle of eruptions is at an end.)

It is hard to convey the scope of the human tragedy the recent eruptions have visited on this small island community. Casualty reports vary widely, but officially, at least twenty-one Montserratians were killed. Between 1997 and 1998, thousands were forced to emigrate, to neighboring islands, Canada, England, or the United States. Many families were separated, and a vibrant and unique culture was temporarily put on hold until the volcano settled down and the islanders could begin to rebuild the island's infrastructure.

In the midst of all this suffering, it might seem crass to worry about wildlife. But even before the eruption, Montserrat--a small but lush island--had been getting a great deal of attention from biologists interested in island biogeography. Bat biologists had been at work there since 1978; I arrived in 1993. Since our studies began, my coworkers and I have compiled a reasonably complete natural history often bat species (six fruit bats, three insectivores, and one carnivore that specializes in capturing small fish with its hind feet), covering the good times as well as the periods marred by the overlapping effects of devastating natural disasters.

Hurricane Hugo was the first such disaster under our watch; it smashed directly into Montserrat, careened into Puerto Rico, and eventually hit the eastern seaboard of the U.S. For the fruit bats on the two islands, survival in the aftermath of the storm was a matter of size--the islands' size. On Puerto Rico, fruit bat populations could abandon hurricane-damaged forests and disperse across a larger landmass into unscathed areas. On Montserrat, Hugo was a crushing blow for tree-roosting and other highly specialized bat species; their numbers fell twentyfold. Many fruit bat populations suffered primarily because there was nowhere for them to go. Their roosts and food sources--much of the island's forests, really--had simply been blown out into the Caribbean.

Not all the island's bat populations crashed in Hugo's wake. A large colony of pig-nosed fruit bats roosts in a series of relatively hurricane-proof dares at the northern end of the island. The animal also enjoys a catholic menu of flowers, fruits, insects, leaves, nectar, and even immature legumes. Such omnivory proves to be a powerful survival strategy when disasters limit the availability of particular foods.

I fully expected to spend many years monitoring the post-Hugo recovery of Montserrat's bat populations, with a special focus on the cave-dwelling colony of pig-nosed fruit bats. The 1995 eruption of the Soufriere Hills volcano, however, dramatically redirected my research program.