This website uses strictly required cookies for authentication and secure processing of user data. It does not use trackers or collect any information beyond what users explicitly choose to store. An exception to this rule are the cookies of streaming services (e.g. YouTube) which are loaded on pages with embedded videos. By continuing to use the site, you agree to this cookie policy.
Home
Acoustic Monitoring of bat activity and human disturbance in caves
×
Acoustic monitoring in the cave
Acoustic monitoring in the cave
Image source: BNPD Archives 2025 - All rights reserved

Acoustic monitoring using mobile sensor networks (AudioMoth) to detect and record bat activity, human disturbance, and noise pollution in cave ecosystems.

Key characteristics

Work step
Data collection
Data analysis
Tool purpose
Numeric and Alphanumeric Data
Audio Data
Properties
Professional
Experimental
Keywords
Identification
Acoustic
HUMANITA
Disturbance
Noise pollution

Tool description

Acoustic monitoring using mobile sensor networks provides real-time detection and recording of wildlife activity and human disturbance in cave ecosystems. The devices capture both bat echolocation calls and human-generated noise. Data is recorded in high-resolution audio format and can be subsequently converted to structured Excel files for analysis and archiving with adequate software. It enables assessment of potential impacts of tourism and human disturbance on bat populations and habitat suitability. It provides quantitative baseline data on bat activity patterns and human disturbance impacts, informing management decisions for cave ecosystem protection.

Constraints

  • Late arrival of bat populations in caves reduces data collection window.
  • Battery life limitations require system optimization for continuous recording.
  • Large data volume generated requires substantial storage and processing capacity.
  • Acoustic analysis dependent on background noise levels and environmental conditions.
  • Device positioning critical for accurate species identification and human detection.
  • Requires expertise in acoustic ecology and bat bioacoustics for data interpretation.
  • Cannot differentiate between similar bat species without additional visual confirmation.

Requirements

  • AudioMoth acoustic sensors (4 units minimum for comprehensive cave monitoring)
  • High-capacity SD cards for data storage (full-frame recording 60 minutes before sunrise and 60 minutes after sunset generates ~2GB per day)
  • Rechargeable batteries or solar charging systems for extended deployment
  • Weather-resistant housing and protective casing for cave environment
  • Technical expertise in bioacoustics and audio file processing (Collaboration with bat researchers for species identification verification recommended)
  • Specialized software for acoustic analysis and species identification
  • Regular calibration and maintenance protocols
  • Data security and GDPR-compliant storage systems

Tool Impact

Acoustic monitoring has a low environmental impact, as sensors are passive and non-invasive. They do not disturb cave wildlife or human activities. Any concerns about human perception or data privacy can be managed through careful placement and by focusing on activity patterns rather than individual identification. Properly used, this method provides a low-impact way to assess human presence and bat activities in caves.

Best Practices

  • Four AudioMoth acoustic sensors were deployed at the entrance and inside Kecske-lyuk cave in Forrás Valley, Bükk National Park, Hungary within the Interreg CE project HUMANITA. The devices operated continuously from 60 minutes before sunrise to 60 minutes after sunset, capturing both bat echolocation calls and human-generated noise. The monitoring system detected four bat species (Greater horseshoe bat, Lesser horseshoe bat, Schreiber's bat, and Mediterranean horseshoe bat) and identified human presence through noise signature analysis. Data was recorded in high-resolution audio format and subsequently converted to structured Excel files for analysis and archiving in the shared HUMANITA database. Data integration with visitor counts allowed correlation analysis between tourism intensity and wildlife responses.

Helpful hints to use the tool proficiently

  • Place sensors strategically at both cave entrances and interior locations to capture habitat variation and maximize detection, documenting placement with photos and GPS coordinates.
  • Test sensors in the target environment and plan installations as temporary or permanent based on cave fragility and tourism pressure.
  • Schedule recordings around peak bat activity and record environmental conditions (temperature, humidity, visitor numbers) concurrently.
  • Use reference calls and sound calibration standards to validate automated identification and ensure comparability across sites and periods.
  • Maintain equipment regularly (batteries, storage) and collaborate with local rangers or conservation groups for support and quality control.
  • Compare sites with and without visitor access, and where possible cross-validate acoustic data with visual observations to detect tourism impacts.

Specification

Category Device / Key
Properties
Sensor
Small/light
Can be used in online/live mode
Range
close range
local

Linked tools

Category Tool title and description
Study object
Study focus
Work step
Tool purpose
 Classic Professional Free to use Experimental
Acoustic monitoring guideline

A detailed guideline from the World Wildlife Fund (WWF) on acoustic monitoring.
bat analysis / identification software

Many software programs for analysis and classification of bat call audio recordings are available. Here, a few examples are described.
bat detectors

Bat detectors are acoustic devices that detect ultrasonic wavelengths that are emitted by bats.
NSNSDAcoustics (R-Studio)

Natural Sound and Night Skies Division repository to develop and modernise bioacoustic workflows
Song Meter acoustic devices

The Wildlife Acoustics Song Meter line of acoustic devices records birds, amphibians, bats, and wildlife that vocalise in the audible and ultrasonic ranges. The recorders are equipped with build-in, low-noise microphones and an optional second acoustic mic stub accesory that enables stereo recording.

Gallery

Images

Acoustic monitoring process
Image source: BNPD Archives 2025 - All rights reserved

Legend

Study objects

Microbiota
Humans
Animals
Vegetation, Funghi & Lichen
Habitats

Study focus

Anthropogenic factors and impacts
Biodiversity (Species populations and Community Composition)
Ecosystem State, Structure and Functioning

Work steps

Presentation
Data collection
Plot establishment
Data analysis
Data archiving

Tool categories

TBD
Device
Software
Manual / Guideline / Framework

Tool purposes

Spatial Data
Numeric and Alphanumeric Data
Audio Data
Genetic Data
Photo/Video Data
Non Data generative
Chemical Compound Data