Introduction to Animal Tracking
Animal tracking is the systematic monitoring of animal movements and behaviors using various technologies and techniques. This field combines biology, engineering, data science, and field craft to understand how animals interact with their environment across space and time. Animal tracking matters because it reveals crucial information about habitat use, migration routes, and behavior patterns that are essential for conservation planning, reveals fundamental biological insights about navigation, movement ecology, and social dynamics, enables wildlife management through monitoring of population health and human-wildlife conflicts, provides data for environmental impact assessments, and facilitates the monitoring of ecosystem health by tracking sentinel species. As technology advances, our ability to track animals with greater precision, for longer durations, and with less invasive methods continues to revolutionize our understanding of animal behavior and ecology.
Core Tracking Technologies Comparison
Technology | Range | Precision | Battery Life | Animal Size | Cost | Best For | Limitations |
---|---|---|---|---|---|---|---|
VHF Radio Tracking | 0.5-5km | 10-100m | 3 months-3 years | >10g | $$ | Small/medium animals, dense habitat | Labor intensive, limited data, manual tracking |
GPS Tracking | Global | 3-10m | Days-years (solar) | >20g | $$$$ | Long-distance migrants, inaccessible areas | Battery limitations, poor performance in dense cover |
Satellite Tracking | Global | 250m-1km | Months-years | >20g | $$$$ | Marine species, remote area studies | Expensive, limited data transmission, larger size |
Acoustic Telemetry | 0.5-1km | 1-10m | Months-years | >0.3g | $$$ | Aquatic species, migration studies | Requires receiver array, detection range issues |
PIT/RFID Tags | 1cm-1m | <1cm | Indefinite (passive) | >0.1g | $ | Small animals, fixed locations | Very limited detection range, fixed readers |
Geolocators | Global | 50-200km | 1-2 years | >0.5g | $$ | Small birds, year-round tracking | Recapture needed, low spatial precision |
Accelerometers | N/A | Behavior-specific | Days-months | >1g | $$$ | Behavior studies, energy expenditure | Complex data analysis, limited context |
Camera Traps | Fixed location | N/A | Months-years | N/A | $$ | Rare species, activity patterns | Fixed location, species ID challenges |
Stable Isotopes | Regional | 100-1000km | One-time snapshot | Tiny sample | $$ | Origins, migration connectivity | Limited temporal resolution |
Field Equipment Preparation
VHF Radio Tracking Equipment
- Receiver Preparation:
- Test battery at full volume
- Verify all frequencies detect test transmitter
- Check antenna connections for corrosion
- Pack spare batteries (alkaline lasts longer than rechargeable)
- Weatherproof with protective case
- Antenna Options:
- H-antenna (Yagi): Longest range, directional
- Loop antenna: Good for close tracking, pinpointing
- Omnidirectional: Vehicle mounting, initial detection
- Handheld: Emergency backup, close-range work
GPS/Satellite Unit Preparation
Pre-deployment Testing:
- Activate and test all units before field deployment
- Verify proper data transmission to receiving system
- Configure duty cycles based on study requirements
- Check satellite reception in study-like conditions
- Update firmware and software if needed
Power Management:
- Solar panels should be clean and unobstructed
- Set appropriate fix schedules for research questions
- Configure sleep modes for efficient power use
- Verify battery charging with voltmeter if accessible
- Consider seasonal variation in solar charging potential
Attachment Materials Checklist
- General Supplies:
- Appropriate adhesives (cyanoacrylate, epoxy, Tesa tape)
- Attachment hardware (crimps, kevlar thread, metal rings)
- Measuring tools (calipers, flexible measuring tape)
- Cutting tools (sharp scissors, wire cutters)
- Work surface (cutting board, clean surface)
- Taxon-Specific Supplies:
- Birds: Teflon ribbon, elastic harness material, leg bands
- Mammals: Collars of various sizes, belt material, collar spacers
- Reptiles: Epoxy, hypoallergenic tape, attachment plates
- Fish: Surgical tools, sutures, disinfectant, anesthetic
- Invertebrates: Specialized glue, micro-tags, numbered tags
Attachment Methods by Animal Group
Avian Attachment Techniques
Harness Types:
- Leg-loop harness: Passerines, smaller birds (<100g)
- Backpack harness: Raptors, waterfowl, larger birds
- Neck collar: Geese, swans
- Leg mount: Shorebirds, waders
Material Selection:
- Teflon ribbon: Durable, low abrasion for long-term studies
- Elastic harness: Accommodates body changes, shorter studies
- Weak link material: Programmed breakaway for tag release
Best Practices:
- Ensure proper fit with two-finger rule under harness
- Account for seasonal weight changes
- Position transmitter to minimize aerodynamic drag
- Avoid wing/flight feather interference
- Consider molt patterns when scheduling deployments
Mammal Attachment Techniques
Collar Design Factors:
- Species-appropriate sizing (typically 60-80% of neck circumference)
- Growth expansion for juveniles (expandable collars, break-away sections)
- Weight distribution and counterbalancing
- Visibility considerations (hunting species concerns)
Specialized Attachments:
- Ear tags: Ungulates, livestock monitoring
- Glue-on attachments: Bats, small mammals
- Implantable transmitters: Long-term studies, aquatic mammals
- Tail mounts: Specialized for certain species (beaver, etc.)
Best Practices:
- Allow 2-3 fingers between collar and neck
- Position transmitter ventrally or laterally
- Include break-away mechanisms for long-term deployments
- Consider seasonal neck size changes (rut, winter adaptation)
- Use reflective materials for nocturnal species studies
Reptile and Amphibian Attachment Techniques
- Chelonian Methods (Turtles/Tortoises):
- Carapace attachment with epoxy
- Low-profile streamlined designs for aquatic species
- Counter-weighted designs to prevent flipping
- Snake Tracking Options:
- Surgical implantation (most common)
- External attachment for short-term studies
- Size and placement to not impede movement
- Lizard and Amphibian Considerations:
- Harness designs with minimal skin contact
- Temporary adhesives for short-term studies
- Implantation for long-term monitoring
- Special consideration for species that shed skin
Fish and Aquatic Species Techniques
- External Attachment Options:
- Dart tethers
- Fin clamps
- Dorsal saddles
- Pop-up archival transmitters
- Surgical Implantation Procedures:
- Proper anesthesia protocols
- Aseptic technique requirements
- Suture materials and methods
- Recovery monitoring procedures
- Best Practices:
- Match transmitter size to fish size (generally <2% body weight)
- Position to minimize hydrodynamic drag
- Consider species-specific swimming behavior
- Account for pressure changes in vertical migrators
Tracking Techniques in the Field
VHF Radio Tracking Methods
Triangulation Technique:
- Take bearings from 3+ locations within short time period
- Optimal bearing angles between 30-150 degrees
- Record time between readings to account for movement
- Use GPS to mark exact observer locations
- Calculate location with bearing intersections
Homing Technique:
- Follow strengthening signal until visual contact
- Record actual location of animal
- Minimizes location error but may disturb animal
- Useful for habitat association studies
- Can be combined with behavioral observations
Field Tips:
- Hold antenna overhead for best reception
- Rotate antenna 360° at each sampling point
- Listen for strongest signal, then null signal to pinpoint direction
- Use topography to advantage (track from ridges/high points)
- Be aware of signal bounce in mountainous terrain
Automated Tracking Systems
Fixed Receiver Arrays:
- Automated Radio Telemetry:
- Tower height determines detection range
- Directional antennas increase precision
- Time synchronization between stations critical
- Power supply options (solar, battery, grid)
- Acoustic Arrays:
- Receiver spacing based on detection range
- Account for environmental attenuation factors
- Download schedule for long-term deployments
- Mooring design for stability and retrieval
- Automated Radio Telemetry:
Data Management Considerations:
- Automated data filtering for false detections
- Regular data download procedures
- Battery replacement schedules
- Weather/tampering protection for equipment
- Redundancy in critical monitoring areas
Remote Download Systems
- GSM/Cellular Networks:
- Coverage mapping before deployment
- Data transmission schedules to optimize battery
- SMS vs. data mode options
- SIM card and data plan management
- Satellite Communication Systems:
- Argos, Iridium, Globalstar options
- Data compression techniques
- Transmission window scheduling
- Bandwidth limitations management
- Base Stations:
- UHF/VHF download stations
- Strategically placed for animal movements
- Download range limitations
- Data storage capacity considerations
Data Analysis Approaches
Movement Analysis Techniques
Home Range Estimation:
- Minimum Convex Polygon (MCP):
- Simple boundary around all points
- Heavily influenced by outliers
- Various percentage options (95%, 100%)
- Kernel Density Estimation (KDE):
- Probability distribution of space use
- Bandwidth selection critical (h-ref, LSCV)
- 50% KDE identifies core areas
- Time-Local Convex Hull (T-LoCoH):
- Incorporates temporal information
- Better for variable movement patterns
- Identifies revisitation patterns
- Minimum Convex Polygon (MCP):
Path Analysis Methods:
- Step length and turning angle distributions
- First passage time analysis
- Correlated random walk models
- Behavioral change point analysis
- Integrated step selection functions
Habitat Use Analysis
- Resource Selection Functions (RSFs):
- Compare used vs. available habitat characteristics
- Logistic regression to calculate selection probability
- Various orders of selection (Johnson’s framework)
- Availability definition critically important
- Step Selection Functions (SSFs):
- Compares used steps to random alternatives
- Incorporates movement constraints
- Better for dynamic resource selection
- Can include directional persistence
- Integrated Approaches:
- Hidden Markov Models for behavioral states
- State-space models for incomplete observation
- Mechanistic movement models
- Individual-based movement models
Social Network Analysis
- Network Construction Methods:
- Proximity-based networks (contact definition)
- Temporal association patterns
- Directed vs. undirected interactions
- Weighted vs. binary relationships
- Network Metrics:
- Individual-level: degree, betweenness, closeness
- Group-level: density, modularity, clustering
- Dynamic metrics: temporal stability, fission-fusion
- Disease transmission applications
Software Tools for Analysis
- GIS Platforms:
- ArcGIS with Movement Ecology Tools
- QGIS with Animal Movement plugin
- Google Earth Engine for environmental data
- R Packages:
- adehabitatHR, adehabitatLT (home range, trajectory)
- amt (animal movement tools)
- ctmm (continuous-time movement modeling)
- moveHMM (hidden Markov models)
- momentuHMM (multi-state modeling)
- Specialized Software:
- Ranges (home range analysis)
- Geospatial Modelling Environment
- Circuitscape (connectivity modeling)
- Trackplot (3D visualization)
Specialized Tracking Techniques
Genetic Tracking Methods
- Non-invasive Sampling:
- Scat collection protocols
- Hair traps design
- Environmental DNA collection
- Proper sample storage (silica, ethanol, freezing)
- Analysis Approaches:
- Microsatellite analysis for individuals
- SNP panels for population assignment
- DNA barcoding for species identification
- Relatedness analysis for dispersal patterns
- Applications:
- Population density estimation
- Movement corridor identification
- Dispersal pattern detection
- Kinship mapping
Stable Isotope Tracking
Sample Collection:
- Tissues with different turnover rates:
- Blood: Recent diet (days to weeks)
- Muscle: Medium-term diet (weeks to months)
- Bone collagen: Long-term diet (months to years)
- Keratin (hair, feathers): Growth period diet
- Tissues with different turnover rates:
Common Isotope Applications:
- δ²H (hydrogen): Latitudinal movements
- δ¹⁸O (oxygen): Elevation, precipitation patterns
- δ¹³C (carbon): Dietary sources (C3 vs. C4 plants)
- δ¹⁵N (nitrogen): Trophic level, marine influence
- δ³⁴S (sulfur): Coastal vs. inland habitats
Analysis Considerations:
- Isoscapes for geographic assignment
- Mixing models for dietary analysis
- Accounting for tissue discrimination factors
- Bayesian assignment frameworks
Biologging Beyond Location
- Accelerometry:
- 3-axis data collection
- Sampling frequency considerations (1-50 Hz)
- Behavioral classification approaches
- Energy expenditure estimation
- Physiological Sensors:
- Heart rate monitors
- Body temperature loggers
- Dive depth recorders
- Stomach temperature pills
- Environmental Sensors:
- Light level for GLS
- Temperature profiles
- Salinity sensors
- Camera triggers
- Audio recording
Emerging Technologies
- ICARUS System:
- International Cooperation for Animal Research Using Space
- Very small transmitters (~5g)
- Global coverage via ISS
- On-board acceleration and environmental data
- Low-orbit Satellite Networks:
- Improved latency and power requirements
- Smaller tag sizes possible
- Higher bandwidth data transmission
- Real-time tracking capabilities
- Animal-borne Video Systems:
- Behavioral context for movement
- Prey capture documentation
- Social interaction recording
- Habitat use visualization
Fieldwork Practicalities
Capture and Handling Best Practices
- Pre-capture Planning:
- Appropriate permits and approvals
- Weather considerations for animal safety
- Team roles and responsibilities
- Emergency protocols
- Minimizing Stress:
- Limit handling time (<30 minutes ideal)
- Monitor body temperature during handling
- Use blindfolds for visual predators
- Keep noise levels low
- Consider timing relative to feeding/breeding
- Safety Protocols:
- Species-specific restraint techniques
- Proper PPE for handler protection
- Clear communication systems
- Medical equipment availability
- Release procedures and monitoring
Field Data Collection Standards
- Essential Deployment Data:
- Animal ID and transmitter ID/frequency
- Age, sex, weight, measurements
- Deployment date/time/location
- Photographs from multiple angles
- Health assessment metrics
- Release behavior observations
- Field Notebooks/Apps:
- Standardized data sheets
- Weather conditions during tracking
- Observer name and experience level
- Equipment settings used
- Metadata for all observations
- Data Management:
- Daily data backup procedures
- Consistent file naming conventions
- Error checking protocols
- Data entry verification system
- Version control for processed data
Troubleshooting Common Issues
- Signal Loss:
- Systematic search patterns for VHF
- Expanded search area beyond expected range
- Aerial tracking for larger-scale searches
- Alternative frequencies check (if tag switches)
- Equipment verification with test transmitter
- Equipment Failure:
- Battery testing protocols
- Connection and antenna checks
- Receiver calibration verification
- Weather-related malfunctions
- Field repairs for common issues
- Attachment Failures:
- Visual inspection protocols when possible
- Monitoring movement patterns for abnormalities
- Recapture decision criteria
- Modified attachment for redeployment
- Documentation for future improvement
Advanced Study Design Considerations
Sample Size and Statistical Power
- Determining Optimal Sample Size:
- Research question specificity
- Expected effect size
- Individual variation in target species
- Tag failure rate consideration
- Budget and logistical constraints
- Sampling Strategy:
- Random vs. stratified selection
- Sex ratio considerations
- Age class representation
- Geographic distribution
- Seasonal deployment timing
Experimental vs. Observational Approaches
- Manipulative Experiments:
- Translocation studies
- Before-After-Control-Impact designs
- Controlled exposure experiments
- Resource manipulation studies
- Observational Strengths:
- Natural behavior documentation
- Long-term movement patterns
- Population-level inference
- Multiple hypothesis testing
- Unexpected discovery potential
Integration with Other Data Types
- Environmental Data Sources:
- Remote sensing products (NDVI, land cover)
- Weather and climate datasets
- Topographic variables
- Human disturbance metrics
- Resource availability mapping
- Complementary Methods:
- Camera trap networks
- Environmental DNA sampling
- Traditional survey methods
- Citizen science observations
- Historical occurrence records
Ethical and Regulatory Considerations
Permitting Requirements
- Government Permits:
- Wildlife agency approvals
- Endangered species permits
- Protected area research permissions
- Import/export permits for equipment
- CITES documentation for samples
- Institutional Oversight:
- Animal Care and Use Committee approval
- Institutional Review Board (if human components)
- Field safety review procedures
- Liability insurance requirements
- Data management and sharing plans
Animal Welfare Considerations
- Weight Guidelines:
- <3-5% of body weight standard
- Species-specific recommendations
- Additional weight considerations for flying/swimming species
- Aerodynamic/hydrodynamic effects beyond weight
- Long-term Impacts:
- Behavior modification monitoring
- Survivorship comparison with unmarked animals
- Reproductive success tracking
- Tag removal or drop-off mechanisms
- Recapture monitoring protocols
Community Engagement Strategies
- Stakeholder Involvement:
- Landowner permissions
- Indigenous knowledge integration
- Citizen participation opportunities
- Local guide employment
- Results dissemination to communities
- Communications Planning:
- Media engagement protocols
- Tracking website considerations
- Educational outreach materials
- Data privacy and security
- Sensitive location protection
Best Practices for Successful Tracking Studies
Study Design
- Begin with clear, answerable research questions
- Match technology to specific questions and species
- Consider full lifecycle including deployments, data collection, and analysis
- Include control groups when possible
- Plan for equipment failures and replacement needs
- Create detailed protocols for all procedures
Field Implementation
- Test all equipment in study-like conditions before deployment
- Train team members thoroughly on handling and tracking methods
- Document all procedures with photos and detailed notes
- Standardize data collection across multiple observers
- Implement rigorous safety protocols for humans and animals
- Establish communication systems for field teams
Data Management
- Create standardized formats for all data types
- Implement daily backup procedures in the field
- Develop clear data processing workflows
- Document all filtering and cleaning procedures
- Consider data sharing and archiving from the beginning
- Use consistent metadata standards
Analysis and Reporting
- Account for sampling biases in analysis
- Report tag effects and failure rates transparently
- Clearly communicate limitations of technology
- Consider biological significance beyond statistics
- Share findings with management agencies and stakeholders
- Publish negative results to improve the field
Resources for Further Learning
Professional Networks
- Movebank (www.movebank.org)
- Motus Wildlife Tracking System
- ICARUS Initiative
- European Tracking Network
- Ocean Tracking Network
- Zoatrack
Equipment Manufacturers
- Advanced Telemetry Systems (ATS)
- Lotek Wireless
- Telonics
- Wildlife Computers
- VEMCO/InnovaSea
- Cellular Tracking Technologies
- Biotrack/Lotek
- Migratory Connectivity Project
Software and Analysis Resources
- R Spatial Packages (adehabitat, ctmm, amt)
- QGIS and ArcGIS plugins
- Movebank Data Repository
- GitHub repositories for tracking analysis
- MoveApps platform
- Animove Training Program
Key Literature and References
- “Research Techniques in Animal Ecology” (Boitani & Fuller)
- “Animal Movement: Statistical Models” (Hooten et al.)
- “Practical Handbook on Image Processing for Scientific Applications” (Bernd Jahne)
- “Tracking Animals in a Dynamic Environment” (special issue in Philosophical Transactions B)
- “Habitat Selection in Animals” (Johnson 1980)
- “Methods in Animal Movement” (Hebblewhite & Haydon)
This comprehensive cheatsheet provides a structured overview of animal tracking methods, from technology selection to field implementation and data analysis. Whether conducting research, conservation monitoring, or wildlife management, these guidelines will help researchers implement effective tracking studies across diverse taxa and ecosystems.