In celebration of International Bat Night, our expert bat researcher Kaushik Narasimhan explains the important role that bats play within an ecosystem
Bats have a bad reputation. Dubbed blood suckers and disease carriers, they are feared and persecuted across the world.
In reality, we have a huge number of reasons to thank and celebrate bats, not simply because they are fascinating creatures in their own right but they also help people in countless ways.
Did you know, for example, that bat guano (or poop) formed the economic backbone of many Latin American countries before the advent of artificial fertilisers? In Peru, the mid-19th century is referred to as the Guano Era due to the stability and prosperity that the export of guano brought to the country.
To this day, bats continue to benefit people but our ignorance and environmentally damaging behaviour is threatening their survival.
For the past three months, Kaushik Narasimhan and Claudia Pérez have been researching bats here in the Manu Biosphere Reserve in the Peruvian Amazon – one of the most diverse places on Earth for bat species.
Manu is an area the size of Wales or Connecticut and is home to 92 species of bat, compared with the UK’s 18 and the United States’ 40 species.
Kaushik and Claudia have been carrying out their work here at our field research station, the Manu Learning Centre (MLC), with the aim of better understanding how different levels of forest destruction has impacted bat species assemblage, richness and diversity.
The MLC’s regenerating rainforest is the perfect place for these studies as the reserve was once farmland and the forest has suffered different levels of destruction by people in the past; one area was completely cleared, another area only partially cleared, and the third section was selectively logged. The bat team surveyed in each of these areas of regenerating forest to compare data on the species they found.
During his time here, Kaushik was affectionately dubbed Batman and our volunteers were delighted to get the unique experience of assisting in his research. They joined him and Claudia for nights in the forest where they captured a huge variety of species – a total of 47, more than the entire number of species that exist in the US.
The volunteers got an up-close look at the fangs, the huge pointed ears, the bizarre skin folded noses and learnt to appreciate the weird, the wonderful, the cute and the ugly.
A real people person with a passion for his work, Kaushik took the opportunity to teach the volunteers about the importance of bats.
“The role that bats play within the ecosystem is rather understudied”, explained Kaushik. “There’s a concept called ecosystem services that basically means looking at how animals – in this case bats – directly benefit humans.”
One of the ecosystem services that bats provide is eating insects and this is really helpful for farmers.
“Not only does it save on crop damage”, said Kaushik, “but it also saves on insecticides and fertilisers. The benefits are multifaceted in that respect.”
While helping to protect plants from pests, bats also disperse seeds and fertilise soil.
“Many of the bats that we’re catching here are herbivores”, said Kaushik. “They don’t eat the fruits right on the spot where they pick them from the tree. They’ll eat some of it and then take it to another destination, eat some more, then either they drop what they don’t eat or the seeds come out when they defecate later on. Their poop is this nutrient-rich mass that’s filled with seeds and it lands far away from the host tree. That’s the perfect conditions to kick start the growth of a new tree. So they’re amazing seed dispersers.”
Other bats are specialised nectarivorous, meaning they almost solely drink nectar.
“They have these incredibly long tongues”, said Kaushik, “that are sometimes half the length of their body and if you x-ray them you can see that they retract back into their body cavity.”
Just like bees, when the bats drink the nectar their body gets covered in pollen.
“They’re nice and furry”, said Kaushik, “so the pollen gets all over them and because they can fly great distances they can pollinate huge swathes of plants.”
Many plant and bat species have a symbiotic relationship, evolving ways to utilise one another.
“Some plants bloom at night”, explained Kaushik “and their shapes have developed in such a way so that they reflect as much energy as possible when the bats are echo locating, making them easier to find.”
It’s difficult to calculate all the numerous ways that bats perform ecosystem services and there have been very few studies into valuing their benefit to people. But the few hard figures that we know are impressive.
“In the United States”, said Kaushik, “a small colony of about 20 to 30 bats saved farmers millions of dollars a year. Here in Manu there are millions of bats, so you can imagine the impact they must have. It’s hard to quantify but that would an interesting realm of research.”
Thanks to Kaushik and Claudia, we now have a much better understanding of the bats here at the MLC, as they discovered 37 new species to our reserve. They also inspired and educated everyone here, giving us greater knowledge and appreciation for the role that bats have within the ecosystem.