Four little brown bats, who took up housekeeping last summer in one of Chautauqua Institution's 50 new bat houses, slipped into the same tiny house this spring.
For the Chautauqua Bird, Tree and Garden Club and several Canadian research students, the bats' return for a second season to a new home signaled success for a $24,000, three-year experiment to keep the creatures summering at Chautauqua.
Unfortunately for the experiment, they were one of only two small colonies to even take advantage of the new living quarters built over the last couple of years to what everyone hoped were bat specifications. The key component to the success of the program, sponsored by the women's club, was to design a new house that bats would like. Most of the bats had been excluded from their Victorian attic homes as human space became scarce. The new homes, it was hoped, would halt, or at least a slow down, the noticeable out-migration over the past few years of mosquito-eating mammals.
The other pair, who tried out a "Missouri-style mansion" last summer, big enough for at least 200 brown bats (Myotis lucifugus), didn't renew their lease this season, according to Alison Neilson, one of the Canadian graduate students involved in the experiment.
Nonetheless, Ms. Neilson is optimistic that tree-shrouded Chautauqua, situated on the shoreline of Lake Chautauqua's perfect breeding grounds for mosquitoes, has stabilized its bat population at about 10,000. She is also optimistic that the day will come when many of the other new bat houses will have satisfied tenants.
That is welcome news since, according to the experts, a single bat can eat up to 3,000 mosquitoes a night without, as bat advocates like to point out, causing a ripple in the ozone layer. They are ecologically sound pest controllers.
For its first 100 years or so, Chautauqua's vintage Victorian homes were favorite summer places for families and brown bats. Most of the homes had warm, unused attics perfect for the bats penchant for hanging upside down during daylong naps and were close enough to the lake waters for the nightlong bug-feeding forays.
But during the past five to 10 years, the institution has been discovered by more and more investor-homeowners. Housing prices, including summer rentals, have skyrocketed, making it lucrative for those unused attics to be converted into expensive apartments.
The bats returned from winter hibernation to discover they had been kicked out of the attics they had called home for years. The creatures are known to live as long as 30 years.
It didn't take too long before members of the Bird, Tree and Garden Club realized that the number of bats seemed to be diminishing.
The club decided to launch a three-year research program specifically aimed at finding new, on-the-grounds bat housing. It retained Dr. Brock Fenton, a biologist and bat expert at York University in Toronto who had often vacationed at Chautauqua. Under his direction, teams of graduate students began an intensive study of Chautauqua's bat population, experimenting with various types of bat houses and initiating educational programs to dispel terrifying myths about bats.
In an effort to track the bats, the students have banded about 6,000 bats since the project began in 1988.
"We are identifying from 10 to 20 percent of them returning here each summer," Ms. Neilson said, "and some of them have been found in the exact same houses for the third year, so we know they have that loyalty to a specific place and that makes it very difficult to persuade a colony to move."
Studies have also shown that it is not uncommon that a vacancy period for new bat house can be at least 18 months.
Melanie Watt, a doctoral candidate who is with the Canadian team this summer, is focusing her research on DNA fingerprinting of the bats.
"Like humans," she explained, "every bat has a specific blood fingerprint. All we need is a tiny drop of blood from the bats and we will be able to determine whether the colonies (which can range from 30 to 400 or more) are genetically based. If this is true, we might want to place two or three of the related bats into a new house and this might help encourage them to set up housekeeping."
Chautauqua is not alone in trying to find the dream house for bats. Different models are being offered by major catalog houses. Dr. Merlin D. Tuttle, who started Bat Conservation International nine years ago, has two models, neither of which has been successful, so far, at Chautauqua.
The house, which is favored by Dr. Fenton and researchers at York University, is the "small Minnesota bat house" designed by the Minnesota Department of Natural Resources and the model for the house the four bats returned to this spring.