Bat Diaries

Recordings and text by Felicity Ford (June-July 2014)

Bat diaries #1

Pipstrelle bats in the garden, 25th June, 22:26

This summer I have been gardening a lot; the days are long and hot and my preferred time to do a few jobs is at dusk when things are cooler. I weed, water things, check on plants, pot on seedlings, tidy away tools. When I am done, I watch the sun set over the shoulders of the houses, and I listen to the sounds.

There is an amazingly regular sequence to the dusk;

First, the blackbirds make their announcements; alarm calls usually, because of a fox that has made its home next door. Then the swifts start moving in dribs and drabs across the sky. Their high pitched sounds drift down as they head home to roost, and sometimes they are joined by a lone seagull, its mournful cry unfurling on the air. To this mix are added police sirens wailing from the town, the occasional gate latch squeaking in our street, and the low, omnipresent rumble of the traffic. The suburban dusk, the sound of home.

Then, out of the inky trees, fluttering shapes appear, moving in crooked lines in the dark: bats.

There are at least two. They circle the garden nightly, hoovering up the moths and mosquitoes and sometimes skimming just over the top of my head.

One night, watching this lovely, quiet dance, I decided to make a sound diary of their comings and goings and to share my recordings here.

I got a Magenta Bat4 Precision detector to plug into my Edirol R-09, and shall make infrequent recordings with this set up throughout the summer. Sometimes my partner, Mark, will join me. The detector has a speaker on it, enabling us to listen to the bats together while I record, and as we don’t speak in the frequency range for which the detector is designed, we can talk without altering the recordings. This makes this one of the most sociable recording ventures I’ve ever embarked on!

This is the first recording, made on 25th June at 22:26 in the evening. We stood by the back door and listened, marveling at our tiny flying mammalian comrades, who are – like the blackbirds, the swifts, the fox, the sirens, the seagulls and the cars – another feature of the place that we call home.

The detector parses the echo location sounds produced by bats into frequencies that humans can hear. The Common Pipistrelles which visit our garden produce sounds at around 39 – 49kHz. I won’t edit the recordings apart from taking out silence at the start. Silences between sounds are left in, as these are the timings produced by the bats as they flit in and out of different gardens on their nightly insect rounds, and leaving them in gives some sense of the time spent, standing, at dusk and listening and laughing, in wonder.

Bat diaries #2

Pipistrelle bat in the garden, 27th June, 22:41

Just one bat this time.

Bat diaries #3

Pipistrelle bats in the garden, 8th July, 22:09

Levels were set a bit higher this time, so it’s a louder recording, though I’m not sure that better. Two bats, seemingly very energetic.