Tracking cryptic animals using acoustic multilateration: A system for long-range wolf detection

Area of Science:

• Wildlife biology
• Bioacoustics
• Conservation technology

Background:

• Studying wild animal behavior necessitates non-invasive observation methods.
• Elusive species like wolves (Canis lupus) pose significant challenges for traditional tracking.
• Existing methods like GPS collars have limitations such as battery life and capture-related stress.

Purpose of the Study:

• To present a novel system for accurately locating wild wolves using their vocalizations.
• To overcome the limitations of current animal tracking technologies for difficult-to-study species.
• To provide a non-invasive tool for wildlife research and conservation.

Main Methods:

• Utilized a multilateration system based on time-of-arrival differences of howl vocalizations.
• Synchronized multiple acoustic recorders using Global Positioning System (GPS) time signals.
• Deployed the system in Yellowstone National Park for two years to collect howling data.

Main Results:

• Successfully recorded over 1200 instances of wolf howling behavior.
• Achieved accurate wolf localization, with location error as low as approximately 20 meters.
• Enabled location determination up to 7 kilometers away, often during nighttime or when human observation is impossible.

Conclusions:

• The GPS-synchronized howl multilateration system offers a viable, non-invasive alternative for tracking wolves.
• This technology provides valuable, otherwise unobtainable, location data crucial for wolf conservation and management.
• The system demonstrates significant potential for studying other elusive, vocal wildlife species.