Bat Walk 2018

This year the bat Walk took place on 04 July.  Once again we were pleased to have Dr Jon Russ of Ridgeway Ecology and Warwickshire Bat Group to lead the event. We also had several members of Warwickshire Bat Group who helped to provide information during the evening.

Because it was so close to the longest day of the year it was quite late before it started to get dark and the bats started to fly.  It was also lovely evening.  There were 33 people who attended the evening.

Jon introduced the evening with a short talk about bats:

Bats are the only mammals who can fly, as opposed to glide as some others can.  There are about 1250 species to be found around the world but in the UK we have about 18 species.  The largest being found among Asian Fruit Bats. These can have a wingspan of up to 6 feet and are often called Flying Foxes.  Whilst the smallest bat is the bumblebee or Kitti’s hog-nosed bat. It weighs just about two grams and it is found in Thailand and Burma.

Bats feed on Insects, invertebrates, fruit, nectar, other bats , birds….and blood. However, ‘vampire bats’ live in the rain forests of America and their preferred prey are large birds, horses, cows and pigs. They do not kill their prey but just take small quantities of blood. (We are not going to be subject to Dracula-like attacks in Kenilworth)

In the UK all bats feed on insects. The smallest bat being the pipistrelle and the largest the Noctule.

In Abbey Fields we are likely to see Pipistrelle Bats, Noctule Bats, Brown Long-eared bats and Daubenton’s Bats.  They like to roost and crevices in buildings, trees, roof spaces, bat boxes and other similar spaces.  Different species have different preferences as well as different preferences for the numbers who roost together. More details can be found on the Warwickshire Bat Groups web pages.

Male bats tend to be solitary, whilst female bats will roost in Maternity Roosts until the autumn when they fly off to join the males who often have harems! The female will store their fertilised eggs until spring when the ‘pups’, baby bats, are born. Usually only one baby is produced by a female each year.

Bats in the UK, like many of our native mammals, are in serious decline.  The use of insecticides is killing their food sources and also their roosting habitats are under threat as a result of special treatments given to timber materials and bats become entangled in modern roofing membranes. This all exacerbates their slow rate of reproduction.

At then end of his talk he showed us a rescued bat. It had had its wing damaged.  An image of a similar bat which was shown in a previous year can be seen here.

As dusk fell, Jon and members of Warwickshire Bat Group loaned out several bat detectors and we walked along to close to the barn. Here, using the bat detectors, we were able to hear the bats as they flew above our heads hunting their prey. They fly very quickly and were all but impossible to see in the gloom. However where they flew across a gap in the trees they could be seen silhouetted against the sky.

Image by David Emsley

A typical bat detector – other brands are available

Image by David Emsley

Listening and Watching for bats

Image by David Emsley

Listening and watching for bats

Photographs by David Emsley

We then walked down to Abbey Fields lake to listen to see if we could hear any Daubenton’s bats.  These fly in the darkness, low, over water. Some were heard.

Image by Paul Fitzpatrick

Bat Flying – outlined against the sky

Image by Paul Fitzpatrick

Bat Flying outlined against the sky

Image by Paul Fitzpatrick

Enlarged image of bat flying

image by Paul Fitzpatrick

Bat flying – outlined against the sky

Photographs by Paul Fitzpatrick

Our thanks go the Jon Russ and the Warwickshire Bat Group members for making this a very interesting evening.

David Emsley FOAF