When David Endacott has finished a bellringing session he often climbs the church tower to see if there are any bats in the belfry.

So, while he is admiring the bells, he is also looking out for tell-tale signs of the presence of bats, such as droppings or the remains of insects — for example butterfly wings — they have been eating.

“Bats and bellringing go well together. Church towers, and particularly cathedral bell chambers, are ideal for locating bats,” said David, chairman of the Oxfordshire Bat Group.

He is always on the watch for bat roosts and, along with other volunteers in the group, he has been undertaking the annual summer survey for the national bat monitoring programme run by the Bat Conservation Trust.

David, who lives in East Challow, near Wantage, co-ordinates the survey in the southern half of Oxfordshire, and Reg Tipping, of Bodicote, near Banbury, looks after the northern half of the county.

Volunteers visit known nursery roosts at least twice over two months in the summer so that they can count the early and later births of bat babies.

“Sometimes I make a visit in August as well to cover the period when mother bats are giving birth. For example, there is a roost near Nuneham Courtenay where the bats always seem to give birth later than at other roosts. So I go to that roost in August,” said David.

Over the past ten years, he has found the number of bats has declined a little, but most populations have stabilised, with an average of 75 to 85 mothers and babies in a nursery roost.

“Numbers do fluctuate a bit, often depending on the weather, as bats mate in September and do not give birth until the following summer.

“One of the roosts of pipistrelle bats near Faringdon has been fairly consistent over the years and can have as many as 110 mothers and babies,” said David.

Pipistrelles are the most common bats in the country and are most often spotted flying at dusk over the Oxfordshire countryside, although brown long-eared bats are being seen more often.

All bats are protected species and are the only mammals capable of sustained flight.

“Years ago, bats were regarded as horrible creatures, but these days people are much more enlightened and are interested in bats. To promote an interest in bats I give many talks to organisations and lead bat walks,” said David.

Over the years, regular monitoring has found that bats generally have stablisied but neither has there been a massive increase.

“We feel that in southern central England, including Oxfordshire, bats have remained consistent in numbers although this is a region of high-intensity farming,” he said. The use of agricultural chemicals on crops has not done bats any favours but fortunately agricultural practices are improving.

“Chemical spraying is much more sophisticated now and is carried out closer to the ground so there is not so much drift of spray in the wind. And chemicals are aimed more at individual weeds rather than everything that grows. There has also been an increase in hedge and woodland planting and margins at the edge of fields are being left wider — all of which helps insects on which bats feed,” added David.

David has been a bat enthusiast for about 20 years and is often called out to rescue bats, particularly babies that home owners believe have been abandoned.

He will take the “orphans” home and nurture them by feeding a specialist compound until the bats are big enough to release into woods.

The summer survey is just one of several carried out by members of the bat group.

Reg Tipping said: “Later in the year we have a survey for Daubenton’s bats over waterways and there are surveys for Noctule and Natterer’s bats.”

All bats have different haunts, for example Daubenton’s are known as the water bat and can be seen flying low over ponds and rivers.

Reg says bat recording is in its infancy when compared with the bird surveys carried out by the British Trust for Ornithology and the Royal Society for the Protection of Birds.

“Years ago it seemed that only country parsons with little else to do counted bats in their churches,” said Reg.

In fact he regards churches in north Oxfordshire as ideal sites for bat roosts, although he did not want to publicly identify the buildings.

Like David, he is fascinated by the lifestyle of bats, such as their ability to preserve their engery.

“Bats will take the warmth from a building like a stone barn to conserve their own energy,” added Reg.

David began his interest in bats when he found an injured bat and asked the Flora and Fauna Preservation Society for help. He had a sticker on his car, which read “Bats need friends”.

One day there was a knock on his door and he found two girls with an injured bat on his doorstep.

“What do you expect me to do?” he asked. The girls replied: “You have a sticker on your car saying ‘Bats need friends’.”

Since then, there has been no way back.

l David can be contacted on 01235 764832. For general information and advice from the Bat Conservation Trust go to www.bats.org.uk