Big bat-watching weekend
Cute, furry masters of echolocation, essential for the health of our planet or blood-sucking fiends that swoop and chitter above our heads?
They may have a reputation as the sinister baddies of the skies but bat fanatics are determined to change negative perceptions.
Saturday marks the 15th annual European bat night and celebrations of the animal are happening across the continent.
From Norway to Portugal, walks and talks aim to get people closer to the misunderstood mammals and improve their chances for survival.
2011 has also been declared the United Nations' International Year of the Bat in an effort to raise their profile and highlight conservation efforts.
Worldwide declines in bat numbers have been described as "alarming" by the International Union for Conservation of Nature (IUCN) with 25% of Europe's 53 species considered threatened.
One of the two main threats to bat populations is habitat loss. But the other is direct persecution by people.
So conservationists are working to improve the relationship between humans and bats.
- Bats are not blind: Many have good eyesight but rely on their hearing for navigation in the dark
- Bats do not get tangled in your hair: Their sophisticated echolocation means they can avoid contact with objects
- There are no vampire bats in Europe: Only 3 out of over 1,000 species are vampire bats and they are found in Central and South America
- Vampire bats would rather not suck your blood: They prefer to feed on large animals such as horses and cows
Dan Merrett is the project co-ordinator for the Count Bat project run by UK conservation charity the Bat Conservation Trust (BCT).
Through their National Bat Monitoring Programme, the longest running multi-species mammal survey in the UK, Mr Merrett says the charity has harnessed "people power" to better protect species.
"Knowing how bat numbers are doing is central to conserving them," he says.
"The thousands of records collected by volunteers around the country allow us to build up trends in bat populations and recognise when there are problems or when things are improving."
But these volunteers are already bat-lovers, willing to stare at the sky on the lookout for bats in one or more annual surveys.
The real challenge for conservationists is encouraging more people to start taking an interest in the often overlooked mammals.Walk of life
End Quote Dan Merret Bat Conservation Trust
When we ran a pilot of the Big Bat Map we found that people in North East England were returning the most records”
As well as organising regular talks to demystify bats, groups of experts and enthusiasts around the country are leading guided walks to get people up close and personal.
"They typically start with a short talk about bats, occasionally with an injured long-term captive bat for people to see up close," explains Mr Merrett.
"Then we hand round bat detectors and troop around listening and looking out for bats."
Bat detectors convert the high frequency calls bats use to navigate to a pitch that humans are able to hear.
The distant fluttering of the winged mammals can often be picked out by a keen-eyed bat-watcher armed with a simple torch and a pair of binoculars. But at the Wildfowl and Wetlands Trust's Arundel reserve, staff are trialling more sophisticated bat-tracking kit.
On walks this summer, the team has used a night-vision scope and LED screen to allow newcomers to watch bats in the dark.
- Join guided walks at dusk or dawn. Night-flying insects peak at these times, so the bats are most active.
- Head out over the bank holiday. August is a key time to see bats, as the young born earlier in the year join adults in flight
- Listen for the flutter. Bats have a more fluttering style of flight than birds and often circle an area as they feed
- Head for water. Daubenton's bats can often be seen skimming the surface of rivers and canals to feed
- Look in the gaps between trees, alongside hedgerows and next to buildings. These are areas where bats roost
"Every bat walk we do people just come away smiling," says grounds manager and bat enthusiast Paul Stevens.
"They are very secretive creatures, they fly at a time when our eyesight isn't very useful. There is that mystery behind them and discovering what they're up to is just fascinating."
In rural locations including the Forestry Commission's Grizedale forest in Cumbria and the National Trust's Brownsea Island off the coast of Dorset, the number of opportunities for guided glimpses are steadily increasing.
But bat-watching is not limited to the countryside, as Mr Merrett explains.
"The great thing about bats is that from spring to autumn they can still be found right on our doorsteps," he says.
"Your back garden or local park is the best place to start looking."
Using Heritage Lottery funding, the Bat Conservation Trust has also made walks more accessible for the visually impaired, hard of hearing and people with learning difficulties.On the map
The charity has also launched an interactive Big Bat Map online to get people participating in local events and mapping their sightings.
"We hope to find out not only where key bat hotspots are but also where people are the most interested in recording bats," says Mr Merrett.
"When we ran a pilot of the big bat map we found that people in North East England were returning the most records, so it will be interesting to see if that holds true now."
Common and soprano pipistrelles are the species most likely to be seen on a bat walk in the UK.
Rarer sightings include the greater mouse-eared bat and Bechstein's bats, with only one known survivor of the former species and the latter only found in deep woodland.
"There's lots to love about bats. If you see one up close you'll find they can be incredibly cute, especially the long-eared bats," says Mr Merrett.
"They are sociable animals and look after each other; the younger bats will even act as babysitters in summer roosts while the new mums go out to hunt."
"With all 18 UK species behaving differently, there's lots to keep you interested and so much that we have yet to learn."
Bats also have an appetite for some of our most troublesome insects.
Tiny pipistrelles that weigh less than a two pence coin are capable of eating 3,000 midges in a single night.
"Research in the US has revealed that insectivorous bats can play important roles in controlling insect pests," says Professor Gareth Jones, who runs the bat ecology and bioacoustics lab at the University of the Bristol, UK.
The value of bats that eat pests on cotton crops in Texas has been valued at $741,000 (£452,000) annually by researchers. Bat pest-control was also deemed beneficial for agriculture by a study in Florida.
Because of their taste for insects, bats are also heralded as biodiversity indicators: a healthy bat population highlights the amount of insect prey and suitable habitat in an area.
"Bats comprise over 40% of native mammalian biodiversity (excluding cetaceans) and several new species have been discovered in recent years," says Prof Jones.
"They are an extremely important component of biodiversity in the UK."