Bat Calls

A team from Bats Conservation International, Paso Pacifico,
 and MARENA studies bats at Volcano Masaya National Park.

Bats are essential to ecosystem health and their populations are dwindling around the world, so it is important to understand individual bat species, bat populations, and, of course, the reasons for their decline. In Nicaragua, we study bat populations and their insect diets because we're considered not just with ecological health, but also with the economic success of Nicaraguan farmers who rely on bats to perform ecosystem services ranging from pollination to pet control.

In the Paso del Istmo biological corridor where we work, there are at least 44 species of bat, which we identify using night photography and by collecting bat guano. By analyzing the DNA in bat excrement, we gather information about what bat species are present and what species of insect they've been consuming.

In Europe, scientists analyze bat calls to understand the various species and their migration patterns. As evolutionary biologist, Kate Jones, of the Zoological Society of London writes at the Independent, "bats leak information about themselves into their environment by emitting high frequency sound – echolocation calls – to navigate and find food.  We can record this sound in standardised ways and identify the species from its call to track changes in bat populations over time."

Jones runs iBats -- the Indicator Bats Program, which helps citizen scientists contribute to biodiversity monitoring for the global conservation community. International monitoring efforts allowed scientists to track bats' migration across borders, but difficulty differentiating among various bat calls meant dispersed data sets were hard to compare. Jones and her team are changing that, developing "an identification system that can be used by anybody."

Their new iBatsID technology, presented today in the British Ecological Society's Journal of Applied Technology, "is able to correctly identify most European bat species 80 per cent or more of the time," making data sets more reliable and easier to compare. Better understanding leads to more effective conservation efforts, so iBatsID is good news for bat scientists, bats, and the people who rely on the ecosystem services bats provide.

To get a better idea of what bat calls sound like, listen this piece from this week's Sunday Weekend Edition on NPR:

For the past five years, bats have been disappearing at an alarming rate, falling prey to a mysterious disease called white-nose syndrome. But they're making an eerie comeback in a new audio exhibit at a national park in Vermont. The exhibit features manipulated recordings of bat calls that are funneled through glass vessels hanging from a studio ceiling. 

Bats emit high-frequency sounds that create echoes to help them navigate and detect predators. Most of these sounds are inaudible to the human ear, but they can be recorded using special machines and software that lower the frequencies into the range humans can hear.

In Nicaragua, we've been monitoring bat calls ourselves. Working with our partners at Bat Conservation International, we've been placing AnaBat systems to record and monitor bat activity across the Paso del Istmo. Rangers at Masaya National Park (like the one pictured above) will share what we learn from our monitoring with visitors and encourage them to help us protect bats and their habitat.

With coverage like the pieces above, we're optimistic about the future of bats. Understanding the economic and ecological importance of our flying mammalian friends, and recruiting citizen scientists, are important steps in bat conservation.

You can contribute to our bat conservation efforts by making a donation today.