Last night I had the wonderful opportunity to head out on The River Cam in Cambridge on a punt. The weather had been beautifully warm and sunny all day yesterday and I had been stuck inside doing housework (with a brief interlude to water the greenhouse). The evening would have been wonderful enough without having a more exciting aim in mind. But first, a couple of sunny pictures I can’t resist sharing!
The BCN Wildlife Trust had very kindly invited me out on this punt as part of a pre-season bat safari! I was so excited when I got the email that it’s all I’ve been talking about since, much to my jealous fiance’s annoyance (it’s okay, I’m taking him later in the year!). A group of about 10 of us headed out at dusk to see what we could find. Our tour guide from the Trust, Iain, was very knowledgable but as I listened to him tell us all about the bats I found it very difficult to pay attention, I was spending much more time watching the banks drift slowly past, listening to sounds of the river and snapping the odd photo before the light got too tricky for my camera!
Bats are nocturnal mammals and they come out at dusk and nighttime to hunt for moths, midges and other insects. We have 18 species of bat here in the UK, 12 of which are resident in Bedfordshire, Cambridgeshire and Northamptonshire. They hunt their food with echolocation. Whales and dolphins also use echolocation to find food too. To use it, the animal will emit a pulse of sound, usually in the ultrasonic wavelengths, and will listen for any echos that bounce back from objects around them. From this they know how far away an object is and with repeated pulses of sound they can locate their prey easily.
On our punt, we’d each been given a bat detector. These work by picking up the ultrasonic signals and through some clever electronics, they convert the ultrasonic signal which humans can’t normally hear into signals we can hear. Long-time readers of my blog might remember when I made a bat detector for 30 Days Wild last year – the ones we used last night were much more sophisticated and much more reliable, but they work on the same basic principle.
Anyway, back to the magic of the punting trip! We set off about 8:15pm last night and punted down the river out towards Granchester. It never ceases to amaze me how quickly the sounds of Cambridge city centre fade away and you’re left with a quiet, tranquil evening. As we floated along the river it brought happy memories of punting with friends as an end of exams treat – the most memorable was when it rained all afternoon and we returned to our colleges completely sodden through but very happy! We were very lucky with the weather last night, the only thing we needed was a little extra cloud cover to keep the warmth in a bit longer!
Bats hibernate over the winter, but they will come out on warm days to feed. This has to be a careful balancing act, if it’s too cold the bat risks not finding enough food and wasting valuable energy (flying is very energy intensive!). This feed can give them a head start when Spring comes around!
As the sunlight slowly faded away, the bats started to appear! We collectively turned our bat detectors on and started to hear the bats! It’s a wonderful moment when you first find yourself surrounded by bats, flitting about and performing displays of aerial acrobatics that the Red Arrows’ would be proud of! I sadly didn’t get any reasonable photos or videos of the bats, so you’ll have to survive with a selection of darkening skylines!
The first bats to come out were the Pipistrelles. We have three species of these in the UK – the Common, Soprano and Nathusius’ Pipistrelles. The common and soprano pipistrelles are our commonest and most widespread bats. They flew around at about the height of punt chauffeurs head and came in close to the punt to investigate us. The other species of bat we saw was the Daubenton’s bat. I loved this bat. It made a different noise on the detectors and our guide had a handheld spotlight which he used to search for the bat and pick it out as it flew. They fly low over the water and are bigger than the Pipistrelles (which are our smallest bats at around 20-25cm in wingspan). They are specialised in this area of prey hunting low over the water, and have another name of ‘water bat’ for this reason.
Of the other species, we were hoping to see a Noctule which is our largest bat with a wingspan of 45cm so these would have hopefully been obvious. They fly earlier in the evening than some bats and some humans can even hear their calls without the aid of a detector.
In short, I had a very lovely evening and as you can tell, I’ve also learnt a lot about these lovely creatures! They have a bit of a bad reputation thanks to Hallowe’en and urban myths, but the few times I’ve been out bat watching I’m always in awe of them. A final fun fact, courtesy of my fiance – bats can purr. He found this out when he was a child at a talk about bats a number of years ago where they brought one in. I think that kindled a love of bats in him that means I’m definitely taking him on one of these punting trips!
Finally, a big thank you to those at the Wildlife Trust for inviting me along and for making it such an enjoyable evening! Thanks also to our punt chauffeur from Scudamore’s Punts on the Cam! If this inspires you to get interested in bats than you can book tickets to go on your own safari via the Scudamore’s website or find out more information on the Wildlife Trust’s website.