COUNTING BATS - It’s more than meets the eye

This year, Bat Count Cayman is aiming to count more bat houses than it’s ever done since the project started. Since 2021, summer has marked a time of year when the Department of Environment and the public turn their gaze to the evening sky, where one of Cayman’s most underappreciated animals rules supreme: the velvety free-tailed bat (Molossus milleri).

Both DoE and citizen scientists from all walks of life venture out at dusk to bat houses across Grand Cayman to witness the emergence of these remarkable creatures as they take to the skies to hunt for insects. In the last 5 years, Bat Count Cayman has conducted 558 surveys by 13 DOE staff members, 10 interns and 43 citizen scientists across 57 bat houses in Grand Cayman. Now in its sixth year, the project aims to recruit more volunteers to count more bat houses than ever before.

Citizen science is the practice of enlisting volunteers to help collect data for scientific analyses and is particularly important when covering large areas and/or over long periods of time.

Bat Count Cayman’s citizen scientists have been integral to the project’s success for both coverage and consistency.

Nancy Barnard, a new recruit to Bat Count Cayman, says, “I joined the bat count this year because I love the work of the DoE and wanted to do whatever possible to help our natural resources. My daughter is home for the summer, and it is a perfect reason to spend an hour with her in peace and quiet, gazing at the glorious sunset and twilight skies whilst counting the bats.”

“We’ve learnt so much through the programme!” Veteran bat counter, Omari Rankine, explains, “I feel that in a time when the pursuit of development and profit is rapidly changing the face of the beautiful country I call home, there should be an equal commitment to protecting the natural environment that makes it so special. Our ecosystems are an essential part of Cayman’s identity, and once they are lost, they cannot easily be replaced. Participating in the annual bat count is my small way of contributing to the conservation of our wildlife and helping ensure that future generations can enjoy the same natural beauty that we have today.”

DOE’s Terrestrial Resource Unit started Bat Count Cayman to examine the condition of and colony sizes within a network of bat houses established in 1994 as part of the National Trust’s Bat House Programme. The network of bat houses provides artificial roosting alternatives and has been available for property owners to purchase since 1994.

The project has since become a platform to highlight the vastly unsung importance of bats to the Cayman Islands.

As of 2013, the National Conservation Act classifies all nine native bat species are Part 1 protected, meaning protected at all times, the same as our native rock iguanas and parrots. However, the role bats play in our ecosystem lacks integration into public knowledge. For instance, M. milleri is one of the most irreplaceable forms of natural insect control on island, particularly for moths, flies and mosquitoes. Maintaining a balanced population of these nocturnal insects would be near impossible without the bats. That is why preserving their habitat and ensuring colonies remain undisturbed are imperative, particularly during the pupping season which spans from May to November, with births being highest in May and juveniles fledging the roost between August and January.

In Grand Cayman, Bat Count Cayman runs from June to August, overlapping with the arrival of new pups. Despite being only the length of your index finger, M. milleri can accelerate to between sixty and seventy miles per hour, speeds at which human drivers are prohibited from reaching on most roads.

In 2021, only twenty-one bat houses were surveyed, whereas forty-one were surveyed in 2022, explaining the 46% increase in the total count. 2023 had the highest count, yet little change in survey effort, which could indicate a successful pupping season from the previous year. The annual number has steadily fallen over the last two years by 19%, despite survey efforts remaining stable. It could be the case that a rainier summer, alongside Hurricane Beryl, in 2024 left less overall foraging time for the bats during the pupping season. A much more arid summer was seen in 2025, one of the hottest and driest on record, which could have impacted insect breeding cycles, thus reducing food availability.

To show our appreciation to our volunteers, Bat Count Cayman has secured sponsorship over the years in the form of prizes which are raffled at the end of the bat count season. In 2026, the selection of prizes have been generously donated by our sponsors: Jean-Michel Costeau’s Ambassadors of the Environment, Foster’s, Kirk Market, Cost-U-Less, and Red Sail Sports.