Journeying With Bats Across Mexico | Perpetual Planet: Mexico

• I just learned how to hold a bat correctly. This is what they do to learn more about the different species that live in this region. They're nervous. We're told to not hold them for very long. It's easy to forget that the nocturnal world is teeming with wildlife. Night creatures like bats are key to the environment's survival, but their mysterious lives and our fear of them have kept bats on the edge of conservation efforts. How can we preserve the wild habitats we love if we ignore the darker side of the planet? Many bat species are endangered, yet few people know why they matter. National Geographic and Rolex are sending me across Mexico to investigate the link bats have to humans and what average citizens can do to help them.

My first stop is the Calakmul Biosphere. The birthplace of an ancient Maya empire that revered bats and home to one of the country's densest bat populations. My journey begins with Begona and Daniela, two researchers taking me to a family of leaf-nosed bats that live in an ancient Maya temple. Threatened by shrinking jungle, ruins like these are their last refuge. Damp and high up, the temples of Calakmul provide leaf-nosed bats with a safe environment, far from human threats like habitat destruction and vandalism.

Wow, beautiful. The nose. Wow. A keystone species, bats indicate the health of an ecosystem. They keep insect populations in check, pollinate plants, and disperse seeds across large areas. Seen as a symbol of fertility, ancient Maya revered bats, endowing them with a mystical status. As dusk settles, we wait at the mouth of a Volcan de las Murcielagos, known as the bat volcano. Sacred to the Maya, it was believed to be an entrance to the underworld. Right now, there are around four million bats leaving the cave and going up in a spiral. They're gonna spread all over.

What's so amazing about this is the sound. (inspirational music) They feast on millions of insects, making the environment habitable. I can see why the Maya revered them. But Begona and Daniela warn me that the bat populations are plummeting, and one of their biggest threats is human persecution. To understand why, I traveled to Tepoztlan to meet the world authority on bats, Dr. Rodrigo Medellin.

• We are taking you into the real home of the one and only mating cave of a Mexican long-nosed bat. We need to use infrared light all along. Be as little disturbance as you can be. -

[Alexandra] Feeding on nectar, the Mexican long-nosed bat is a migrating species closely tied to the seasonal flowering of plants. Due to recent climate changes, having no food source, many are starving to death.

• [Rodrigo] Two or three times I have witnessed a very sad view, which is, walking into the cave and finding the floor of the cave completely covered with the bones of baby bats. -

[Alexandra] As a result of modern myth and pop culture, bats have become synonymous with vampires and the devil. This has led to the vandalism and destruction of their caves.

• And what you can see here is not a toy. It's a real altar to the devil. So people come and do ceremonies and things here for the devil. Unfortunately, they are endangered because people destroy their caves, so the numbers have dropped heavily over the past years. -

[Alexandra] Rodrigo's dispelling these myths by changing common perceptions of bats from demonic villains to ecological superheroes.

• There's three main ecosystem services, or benefits that we get from bats. Pest control, seed dispersal, and the third service is pollination. Without bats, we wouldn't have any crop. Mexicans have a very tight link. The spirit that really designates part of our identity is connected to bats. You drank coffee or tea in the morning, you have a link to bats. You're eating your tortilla corn here, you have a link to bats. Or you're drinking your tequila. Guess what? You have a drink to bats. The Maya really had the right idea. These bats do a lot for us. -

[Alexandra] Species like the long-nosed bats travel from places like the Devil's Cave to Oaxaca to pollinate one of Mexico's most important crops, agave, the plant used to make tequila and mezcal. Mezcal is at the heart of the Oaxacan culture and economy. Agave shortages and a rise in demand for mezcal are posing a compounded threat to bats. Agaves must be harvested before they flower, leaving no food for the bats who rely on pollinating them.

I've come here to meet Graciela, a fourth generation mezcal producer. She harvests in a bio-dynamic manner, leaving a portion to be fertilized by bats, making her mezcal bat friendly and supporting the symbiotic relationship between the animal and the plants. Bats have suffered from being misunderstood and ignored. Bat friendly distilleries help shed light on the connection between bats and people. But what bats need the most is to be championed for what they are, unseen heroes. (gentle music)