The truth about bats and beans

Coffee cultivation, pesticides and hunting are threatening the survival of many species of bat. Can a new brand of 'bat-friendly' coffee help to conserve populations? Sanjida O'Connell reports

Sipping a skinny latte, double mocha, cappuccino or plain old instant, the last thing on your mind is going to be a bat. Yet a company in the US has just brought out a brand of coffee called Bat Magic. In spite of the twee name, its aspirations are serious: bats are endangered worldwide – as a recently published conservation report shows – and coffee cultivation is but one of the myriad ways in which we are killing them off.

Bat Magic beans are grown under the shade of existing rainforest canopy rather than cutting down the trees for cultivation in the coffee-growing regions of Mexico and Central America. This preserves the forests, not just for bats, but for other insects, animals and birds. The bats, in turn, reduce the need for pesticides by eating insects which feed on the coffee bushes, and help regenerate the forests by dispersing seeds and fertilising the soil.

As well as raising awareness about bats, the California based Thanksgiving Coffee Company donates a dollar from the sale of every bag of beans to the conservation organisations, Bat Conservation International and the American Wildlife Trust. The Trust is already using this donation to maintain two projects in Guatemala managed by Lorena Cavlo, a conservation biologist who has been studying the diversity of bats in two types of shade plantations near the town of Quetzaltenango. Half of the farms are traditional polycultures, where the shade trees provide fruit, such as bananas and avocados, and the others are moncultures. She has found a rich bat community in both kinds of farms, but greater numbers in the polyculture coffee plantations.

About a third of Guatemala is devoted to coffee cultivation and Calvo's research over the past few years has focused on whether allowing epiphytes (a type of plant that grows on tree branches) to survive on the shade trees can help to increase insect numbers, and ultimately provide food for the bats and birds in the area. So far it looks as if this does help.

Work like Calvo's is crucial. A recent report by the Species Survival Group of the International Union for Conservation of Nature (IUCN) has shown that of the 1,001 known species of bats, a quarter of them are endangered and 12 have gone extinct. For 60 species there are no data. "A fifth of all mammal species are bats," says Dr Simon Mickleburgh, one of the authors of the report and senior conservation researcher at Fauna and Flora International, "so they are an important group. Their role in ecosystems in vital in many cases as they pollinate or disperse seeds that are of economic importance."

One of the greatest threats to bats is habitat loss, especially due to the expansion of agricultural land. Toxic pesticides such as DDT, which is widely used in developing countries, including Africa where it helps control mosquitoes, can wipe out bats. Removal of forest habitats not only reduces bats' food, but also their roosts. However, many species of bat roost in caves or mines, and the resumption of mining (particularly of limestone in the tropics) or sealing mines can devastate species. In America two mines in Wisconsin were protected from complete closure, which saved more than 600,000 bats from four different species.

"Bats have a bad image and are viewed with suspicion if not outright fear in many countries," says Mickleburgh. The vampire bat is one of the few species that can cause a threat, though mainly to cattle as they feed on their blood and can pass on bovine TB. However, attempts to eradicate the vampires are indiscriminate and ineffective, according to the IUCN report.

The same approach is applied to flying foxes, a species of fruit-eating bat. In the Maldives fruit growers have a policy of a 75 per cent cull. If flying foxes are not shot or poisoned for their predilection for fruit, they are liable to be eaten.

In Guam, between 1981 and 1989, 13,000 flying foxes were imported every year for food. The trade was made illegal when the two main species that were being eaten were listed as endangered. However, illegal trade still continues and many smaller, insectivorous bats have been added to the menu, particularly in the Indian and Pacific Ocean islands. "In many countries bats are eaten but we are not sure what impact this has on the population," says Mickleburgh, "We'd like to assess this trade in what is effectively bushmeat."

The IUCN's Action Plans include conservation measures for the most endangered bats. "First and foremost the plan is an educational tool," says Mickleburgh, "to make countries aware of the issues, what species are in their country, which species are threatened, and how to safeguard them. We need to help them control habitat loss and the threat to roost sites which might require a major change to legislation."

One success story is Action Comores, a conservation organisation dedicated to preserving Livingston's fruit bat through the creation of a nature reserve on the Federal Islamic Republic of the Comores (RFIC) (situated in the Western Indian Ocean between Madagascar and mainland Africa) and by raising awareness. There were only 150 bats left when Action Comores began, but now numbers are closer to 1,000.

Action Comores has created videos, posters, slide shows and material for schools. "It's been really successful," says Simon Garrett, Bristol Zoo's head of education, "From my point of view the big benefit is there is a group of Comorans who are running it, carrying out the surveys and taking an interest and that is an indication that the work has gone well."

Currently Bristol Zoo has bred the bats in captivity and has a small population of 13 in case the wild population is wiped out. "We're also keeping them as ambassadors for education and fundraising," says Garrett, "and for behavioural research."

In the UK, British bats are also on the increase. For example, numbers of the lesser horseshoe bat have risen and the animal's geographic range has also been extended. Legislation put in place in the Eighties gave bats protection and a higher profile. Government funding has enabled more long-term studies to be carried out and technology has helped researchers to discover new bats – recently zoologists found that the famous pipistrelle bat is in fact two, not one species.

We may not yet be able to buy Bat Magic coffee in the supermarket, but we can help bats by providing bat boxes, and growing a diverse range of native species to attract insects which will in turn attract bats.