Go on a bat safari on the River Cam in Cambridge with the Wildlife Trust

They help pollinate plants, help spread seeds and are brilliant for ecosystems – catch them in flight this summer on a thrilling bat safari.

Globally, there are more than 1,400 bat species in the world, but of the 18 species found in the UK, 12 have been recorded in Cambridgeshire.

The most prominent are common and soprano pipistrelles, the Daubenton’s bat (or water bats) and the natterer’s bat. Populations are much smaller than they were 50 years ago, but numbers have steadily increased over the past decade thanks to conservation and efforts to encourage them back into cities.

These astounding mammals - Britain’s only flying mammals - are to be revered, not feared, and do much for the environment, helping pollinate many plant species and dropping fruit seeds.

Bats love insects and so any habitat which attracts bugs will also attract bats: most species will eat in excess of 1,000 insects per hour – a staggering amount, and an indication that they are nature’s pesticide. When considering how much money is invested in chemical pesticides and the collateral damage that these inflict on bee populations, the appropriate management of hedges, roofs and other man-made shelters – places that bats love and feel safe in – is probably a much better way of protecting crops.

Bat life cycle

Spending most of the winter hibernating, bats’ state of inactivity is characterised by a low body temperature, slow breathing, and lower metabolic rate. In February, they’re still hibernating but now have little fat left to live off by this stage, and so may leave the roost on warmer nights to seek food and a drink of water.

During March, they’re beginning to emerge and signs of limited activity can be seen - small numbers will feed as it gets warmer, but in bad weather, they may become torpid again.

By the end of April, many will have come out of hibernation and they will be hungry and active, feeding on most nights. They may move between several roost sites and can become torpid (cool and inactive) again when cold.

In May, bats are now fully active and feeding - females start forming maternity colonies and looking for suitable nursery sites, such as buildings or trees, while males roost on their own or in small groups.

Females usually give birth to a single pup, which they feed on their milk; young bats are very small (less than an inch) with thin, slightly grey fur.

During June and into July, mothers continue to wean babies - some species grow fast and can become almost full-size very quickly. At around three weeks old, young bats start to attempt flight – so babies may sometimes be found on the ground as they are learning; at six weeks old the young bats begin to catch insects for themselves during August, and no longer need their mothers’ milk. The summer maternity colonies begin to disperse and bats will be moving on to mating roosts.

As the mating season begins, the males of most species use special calls to attract females, which can include purrs, clicks, and buzzing. Bats also concentrate on building up fat stores for the coming months, and by October mating is taking place, while the building up of fat reserves is becoming crucial to survive the winter season.

By November, they are once again seeking suitable hibernation sites, from where to begin periods of torpor. By December it’s too cold for flight, so they are fully hibernating, and may roost on their own or in small groups, often in cool, quiet places like disused buildings, old trees or caves, where they hopefully won’t be disturbed.

Wild bat safaris

Coming up from mid-May to mid-September, the Wildlife Trust in Cambridgeshire is running its atmospheric evening bat punt safaris on the River Cam.

Get in quick to book for punts in May: hungry, just-emerged-from-hibernation bats are out avidly seeking food, evenings are cool, but snuggling under rugs in the encroaching dark brings a decidedly ambient charm.

The punts, run in conjunction with Scudamore’s punt company, set off at dusk: hand held bat detectors pick up on bat echolocation, a Wildlife Trust guide interprets bat species from the clicks and squeaks, as well as identifying all the other sounds of the riverbank.

As the sun begins to set, the waterway comes alive with all sorts of wildlife, and the nocturnal sights and sounds create a spellbinding atmosphere. It’s unique and unmissable.

Visit wildlifebcn.org/bat-punts and wildlifebcn.org/support-us.