Volume 22, Issue 3, Fall 2004

Bats Without Borders

Migratory bats have no respect for the borders most nations hold sacred and that creates a host of obstacles for conservation. Ibrahim Rasit Bilgin, armed with intense dedication and a BCI scholarship, is using science to overcome cross-border conservation problems in southeastern Europe.

Throughout most of Europe, the “Eurobats” agreement is designed to preserve bat habitats and roosts across national boundaries. But southeastern Europe presents special challenges: Bulgaria signed on with Eurobats, but Greece and Turkey have not.

Although volunteers and academics work to protect bats in Greece and Turkey, no formal protection exists. Bilgin, of Columbia University in New York, cites an immediate threat to Dupnisa Cave in northwest Turkey, near the Bulgarian border. At one time, the cave hosted an estimated 40,000 bats, including maternity colonies of three species in the summer and hibernation colonies of five others each winter. It was opened for tourism in 2002 and, he says, the maternity colonies have all but disappeared, with just 50 bats remaining.

If these bats migrate among the three countries, as seems likely, Bulgaria’s conservation efforts could be rendered moot by Greek and Turkish inaction.

Bilgin’s “Bats Without Borders” project set out to show that bat populations share the three countries and that cooperative, concerted protection is required.

He chose Schreiber’s bent-winged bat (Miniopterus schreibersi) for DNA analysis to demonstrate movement among individuals in the three countries. He confirmed that bats captured at caves in Bulgaria, Greece and the Thrace region of Turkey (which is geographically part of Europe) are part of the same population. They are, however, genetically differentiated from Schreiber’s bent-winged bats sampled in southern Anatolia (on the Turkish peninsula east of Thrace and separated from it by the Bosporus Strait).

That and other evidence support the presence of these two relatively widespread but distinct populations. Both need protection to fully safeguard the future of Schreiber’s bats in the region.

Bilgin is working now to encourage coordinated, multinational conservation efforts, especially at Greek and Turkish caves, such as Dupnisa. Cave visits, he argues, should be suspended during the summer, when mothers and pups are present. At the very least, they must be strictly controlled.

To support Bat Conservation International’s Student Research Scholarships, please contact the Development Director at (512) 327-9721 or

To support Bat Conservation International’s Student Research Scholarships, please contact the Development Director at (512) 327-9721 or

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