What does it sound like to go bat detecting?

From start to finish, this question has underpinned Walking with Bats. My main goal throughout the album's development has been simple: to transport listeners directly to the field, placing their ears where mine are so they can experience the excitement of bat detecting through their own headphones.

Bats—especially in Western society—continue to endure a variety of negative associations. This is entirely undeserved, and has largely come about through myth, superstition, and a general lack of understanding. In many cultures, bats are unjustifiably regarded as agents of darkness, disease and depravity, and recent misinformation regarding COVID-19 (fuelled by irresponsible social media posts and sensationalist reporting) has led to further public misperceptions about bats: all despite the irrefutable fact that the species responsible for spreading the SARS-CoV-2 virus around the world with unprecedented efficiency is our own.

Let's consider bats objectively for a moment. Over 500 plants worldwide require bats for effective and efficient pollination, including commercially significant species bearing mango and durian fruits. Bats are important insect controllers, with some species consuming up to 3000 per night. Bat guano makes excellent fertiliser, and many communities depend on it for successful crop cultivation. Fruit-eating bats play a key role in dispersing seeds, making an extensive contribution to reforestation in areas recovering from woodland depletion. More broadly, bats are superb barometers of our planet's health, providing early warning signs about habitat damage and insect population declines.

In addition to all of this, the physical capabilities of bats are truly remarkable. Bat mums raise their young on milk just like we do, nursing them with incredible tenderness and expending huge amounts of energy on their care until they are able to fly independently. Bats have membranous (skin-based) wings, and are thus far more manoeuvrable than any bird or aircraft: just watch one turn and spiral on a clear summer evening. Perhaps most impressively, the majority of bat species can literally 'see' using sound, which means they can find their way around with pinpoint accuracy in total darkness. They do this via echolocation, emitting short vocal pulses many times per minute and listening for the echoes, in order to build up a sonic picture of their environment. These sounds typically lie above the range of human hearing, and are described as 'ultrasonic'.

These ultrasonic echolocations—and the fascinating stories behind them—represent the key focus of Walking with Bats. The main portion of the album (Tracks 1–8) features a series of narrated bat walks, documenting my search for various species throughout south-west England and my native Northern Ireland. During these walks, I used one of the most advanced handheld ultrasound detectors in the world (the Pettersson D1000X) to translate bat calls into the human-audible range; as I detected, I also recorded my own contextual narrations, to give listeners a sense of what was happening in the moment and bring them closer to each experience.

The album also contains some useful extras. Track 9 provides a brief explanation of the heterodyne detecting method used for each bat walk. The final four Tracks (10–13) feature some weird and wonderful bonus materials, including: a software-based, spatial reconstruction of the foraging activity of a common pipistrelle; stereo noctule vocalisations, recorded on the edge of a football pitch; the sounds of Natterer's bats gleaning insects directly from the surface of a willow tree; and the captivating, time-expanded melody of a Nathusius' pipistrelle social call.

Over the last few years, I've become ever more conscious of how lucky I am as a wildlife sound recordist: I'm fortunate enough to have financial support for my projects, and can easily drive or hike to locations that interest me. By stark contrast, many people find themselves unable to experience wildlife (or obtain basic equipment to record it) due to physical disabilities or other restrictions. Taking this on board, I developed Walking with Bats as an accessible, narrated experience from the ground up, in the belief that everyone should have an opportunity to understand more about bats, and indeed that bats (as frequently persecuted animals) have an inherent right to have their ultrasonic stories told by us.

With this project, then, my intention has been to establish a reference work for accessible, story-driven bat detection, whose content will hopefully inspire other detectorists to verbally document their field experiences. In this way, we will hopefully develop a more holistic understanding of the fascinating behaviours of bat species, through incorporating our equally fascinating human reactions to them. This can only lead to greater human empathy towards some of our most misunderstood animals, and provide a powerful complement to the scientific discoveries of biologists and other researchers.

So, what does it sound like to go bat detecting?

Pop your headphones on.

Mark Ferguson
Bristol, November 2023

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Development of the field recording techniques used for Walking with Bats was made possible by an Arts Council England DYCP grant, awarded in 2022. My thanks to the Arts Council for approving the project, and allowing me to develop new approaches for ultrasonic storytelling.

I would additionally like to thank: the Bat Conservation Trust (especially Andreia Correia da Costa, Steve Roe and Naomi Webster); Bat Conservation International (special thanks to Kathryn Slater and Rachel Harper); Ricardo Climent; Dave Young; Evelyn Ferguson; David-Lee Badger; Phil Riddett; the Wildlife Sound Recording Society; Lars Pettersson; and my close friends and family in Northern Ireland / Poland.

Produced, mixed and mastered by Mark Ferguson. Original album artwork by Deadbeat Creative Company. All views expressed on this album are my own, and do not represent those of any organisation or individual. All featured members of the public have given full permission to have their voices included, and, where relevant, to have their names listed on associated tracks.

The following texts and websites proved especially valuable for reference purposes during the project, and are recommended for further reading:

Bat Conservation International: www.batcon.org

Bat Conservation Trust: www.bats.org.uk

Deitz., K and Kiefer, A. (2014) Bats of Britain and Europe. London, UK: Bloomsbury.

Middleton, N., Froud, A. and French, K. (2014) Social Calls of the Bats of Britain and Ireland. Exeter, UK: Pelagic.

Russ, J. (2012) British Bat Calls: A Guide to Species Identification. Exeter, UK: Pelagic.