WHAT is the connection between birds, bats and moths?

Or why is bird charity, the RSPB putting on an event to show people bats and moths?

The wildlife charity's Tony Whitehead explains.

THE nature of the environment means all things are connected.

For an organisation such as the RSPB, birds might be the focus, but we can't ignore other creatures or the places they live in. The other thing is that creatures such as birds, bats and moths fly! Bats, along with some birds such as swallows, swifts, house martins and nightjars, also feed on flying insects entirely on the wing. The air above us is teeming with life.

It has been estimated that, in May, a square mile column of air from 20 feet above the ground to 500 feet can contain more than 32 million tiny creatures.

And it is this which attracts the birds and bats. To feed on the wing requires a few design features.

Look closely at swallows, swifts and nightjars, all birds from different families, and you can see they all have large mouths and jaws, relative to their size. These are perfect for scooping up insects in flight. A further design on the nightjar is the provision of stiff feathers either side of the jaw which help widen the gape further and increases the chances of success.

Bats have also evolved some unique design features to feed on the wing. Feeding at night requires bats to be able to locate their prey accurately. They do this by echo location, emitting a regular series of high-pitched calls, too high for humans to hear. When a moth flies in front of them, the sound bounces back and the bat knows there's food to be taken.

The airborne bugs, though, are not without their defences.

To defend themselves against echo-locating bats, many insects have developed the ability to "hear" the bats' clicks.

Some species of moth, notably tiger moths, have taken this one step further. Not only are they able to hear incoming bats, they also use a series of ultrasound clicks of their own to, quite literally, jam the bats' frequency, causing just enough confusion for the moth to escape.

So next time you're out walking on a quiet summer evening, think for a moment of all this activity, of predator and prey locked into an arms race of attack and defence all played out in the dark and at frequencies above our hearing.

The RSPB's bat and moth evening will be heldat Cholderton, near Salisbury, on July 29 from 9pm. Meet at the Source farm shop. Please bring a torch. An adult must accompany children.

The event is free but donations are welcome. For more information, call 01980 629835.