Acoustic recorder
Long-term bird and bat monitoring from a single weatherproof unit. Designed to be deployed and left.
What Demeter is
Demeter is designed around one idea: it should be possible to drive to a site, attach a recorder to a post or tree, and leave it running reliably for weeks without needing to return.
That means low power consumption, a robust enclosure, high-quality audio capture, and firmware that handles edge cases gracefully — SD card full, battery low, clock drift — without corrupting data or requiring a reset.
The result is a recorder that ecological practitioners, researchers, and conservation volunteers can trust with real survey work.
Use cases
Programme Demeter to start recording at astronomical dawn and stop two hours later. Captures a complete chorus without early morning site visits.
Continuous or scheduled recording through the night using the high-frequency microphone. Suitable for NRaPP-standard monitoring with appropriate analysis.
Leave Demeter running for a full season to establish a species inventory and activity baseline before development or habitat management work.
The original deployment environment for Demeter. Compact enough to mount discreetly on a churchyard post or wall bracket without visual intrusion.
Tree mount kit available. Designed to tolerate British weather — rain, frost, and temperature swings — without seal failure or condensation issues.
Open firmware and documented data format make Demeter suitable for research use where reproducibility and data provenance matter.
Technical specifications
| Microphone | Wideband condenser, omnidirectional |
| Frequency range | 1 Hz – 100+ kHz |
| Sample rate | 48 kHz (configurable) |
| Bit depth | 24-bit |
| File format | WAV (uncompressed) |
| Gain | Configurable, 0–40 dB |
| Battery type | Lithium-ion rechargeable |
| Battery capacity | 10,000 mAh (standard) |
| Runtime (continuous) | Up to 10 days |
| Runtime (duty cycle) | Up to 6 weeks |
| Charging | USB-C or solar (via charge controller) |
| Sleep current | < 1 mA |
| Storage | MicroSD, up to 1 TB |
| Included card | 128 GB high-endurance |
| Real-time clock | On-board RTC with supercap backup |
| Timestamp accuracy | < 2 seconds/month drift |
| File naming | ISO 8601 timestamps |
| Processor | ESP32-S3 |
| Enclosure rating | IP65 |
| Operating temperature | –10°C to +50°C |
| Dimensions | 180 × 90 × 55 mm |
| Weight | ~420 g with battery |
| Mounting | Pole, post, or tree bracket |
| Configuration | Plain-text config file on SD card |
| USB | USB-C (data and charging) |
| Wireless | Bluetooth LE (status monitoring) |
| Status LED | RGB indicator (configurable) |
| Firmware update | SD card or USB |
| Demeter unit | ×1 |
| 128 GB microSD | ×1 |
| USB-C cable | ×1 |
| Pole mount bracket | ×1 |
| Silica gel pack | ×2 |
| Quick-start guide | Printed |
In the field
Demeter has been deployed across a range of sites in the Wild Churchyard Project and independent surveys.
8-week continuous deployment. Recorded 23 bird species and 5 bat species including soprano pipistrelle and brown long-eared bat.
Dawn chorus survey across one season. Confirmed breeding of 14 species including lesser spotted woodpecker, a priority species for the landowner.
Three-unit deployment across 120 ha. Built activity baselines for brown hare and hedgehog alongside standard bird and bat surveys.
Buy Demeter
Demeter is available to order directly from Wild Systems Lab. We supply to individual ecologists, conservation organisations, and research institutions.
Current lead time is approximately 3–4 weeks. Volume pricing is available for organisations ordering three or more units. Contact us to discuss your requirements.
Includes recorder, 128 GB SD card, pole mount bracket, USB-C cable, and printed guide. Shipping to UK and EU.
Support
Step-by-step deployment instructions for first-time users. From unboxing to first recording in under 30 minutes.
Download guideFull reference for configuration file options, recording schedules, status codes, and firmware update procedure.
View docsDirect support from the team for hardware questions, deployment advice, and troubleshooting.
Get in touch