What do giant fruit bats have in common with Johnny Appleseed? Tonight’s episode of “One Strange Rock,” National Geographic Channel’s documentary series about the interconnectedness of Earth’s ecosystems, provides an answer that’ll awe the grossologist in your family.
During each rainy season, between October and December, up to 10 million of the bats — also known as flying foxes — converge on Zambia’s Kasanka National Park from all over Africa.
“It’s the largest mammal migration on Earth,” conservationist Frank Willems says in National Geographic’s video clip, available via GeekWire as an exclusive preview for tonight’s show. “They fly out in every direction, covering an area of 10,000 square miles.”
The bats gorge themselves on the waterberries, mangoes, musuku fruit and red milkwood berries hanging from the park’s trees, eating enough to equal half of their body weight each night.
As the bats fly back and forth, the fruit and the seeds pass through their digestive system — and yes, National Geographic shows that part of the process, using what appears to be an internal gut-cam. Then the seeds come out the other end and drop to the forest floor.
“The seeds might end up in a completely different place where a new tree can then grow,” Willems says. “We are looking at literally billions of seeds flying all over the continent.”
Fruit bats thus serve as the African equivalent of the legendary American tree planter, with an added twist courtesy of the alimentary canal. And seeds aren’t the only benefit: A study conducted in Costa Rica and published in the journal Biotropica found that bat guano provides essential fertilizer for tropical forests.
Bottom line? The process outlined in tonight’s episode of “One Strange Rock” may sound batshit-crazy, but it really isn’t. And that’s just a couple of minutes from the 10-part documentary series.
National Geographic’s “One Strange Rock” was produced by Jane Root through her production company, Nutopia, in league with award-winning filmmaker Darren Aronofsky and Protozoa Pictures. The 10-episode series, hosted by actor Will Smith, weaves together visuals and commentaries from conservationists and astronauts to present eye-popping perspectives on our planet. Check local listings, or watch episodes online after they air each Monday.