Variety is the Spice of Life

Lisa Hundt, Head of Biodiversity at the Bat Conservation Trust, explores the connections between bats and tequila!

Today’s the day to celebrate the variety of all living things - it’s the International Day For Biological Diversity! Biodiversity includes all mammals, birds, reptiles, amphibians, fish, invertebrates, plants, fungi . . . everything including you, me and bats!

This variety is essential for the planet and for our way of life. It providing us with essentials (e.g. oxygen and chocolate) and luxuries (e.g. really good chocolate). The diversity of bat species is no exception. In fact, there are more than 1,100 species of bats worldwide, making up around one-fifth of all mammals - and these bats contribute more than most people know to the world’s healthy environment.

This was beautifully demonstrated last week in a talk by Dr Rodrigo Medellin, International Year of the Bat Ambassador. He was in London, to receive the 2012 Whitley Gold Award from Her Royal Highness The Princess Royal (Princess Anne to you and me!) for his work in conserving bats in Mexico and Latin America.

Medellin explained how much we owe to Mexican bats. Mexico has 138 species of bat – including the lesser long-nosed bat that is partly responsible for the pollination of agave plants, the plants which are used to make mescal and tequila! But while bats are good for tequila, tequila is not always good for bats. In the majority of tequila production, farmers harvest the plant before it puts out the flowers that bats feed on and pollinate. Instead, these plants are only allowed to reproduce through cloning. All tequila plants in one farming area have been traced to less than a handful of clones – not a lot of biodiversity there, and with severe consequences. For example, disease has recently killed off more than a third of the agave plants in some areas, something that might have been avoided by allowing the plants to flower and reproduce through pollination. Medellin hopes to persuade tequila producers to allow 1-2% of their blue agave plants bloom, creating a food source for bats and increasing the robustness of their crops.

Medellin also discussed recent research on neotropical bats and their role in forests. These forests have suffered clearing and fragmentation, while hunting and disappearance of habitat has meant that some populations of large bodied animals like deer and macaws have been wiped out. Without these animals, many large-seeded plants have no way of dispersing their seeds . . . or so it was thought!

Recent research has looked at seed dispersal both at random through the forest and underneath the tents of tentmaker bats.

These studies have shown that the number of large seeds under the tents is higher than would occur at random. These tiny (and adorable!) tentmaker bats might be playing a crucial role in the dispersal of 44-65 large seeded plant species throughout the forest.

Closer to home, bats are an essential part of our own native wildlife. With 18 different species here in the UK, they make up almost a third of all mammal species and can be found in lots of different places like wetlands, woodlands, farmland and even your own loft.

They can tell us a lot about the state of the environment, as they are top predators of common nocturnal insects and are sensitive to changes in land use practices. This means that the pressures that they face - like landscape change, development, and habitat fragmentation - are also relevant to many other wildlife species, making them excellent indicators for the wider health of the UK's wildlife.

If you want to help monitor bats and the health of our environment, you can sign up to take part in the National Bat Monitoring Programme.

This video provides an overview of the work of Rodrigo Medellin and his continued conservation efforts to protect bats and other animals in Mexico and Latin America, and goes some way to show why we were extremely lucky to hear a talk from him.