5) Evolution of on-board technologies and AI integration

Advancements in on-board technologies and AI integration hold great potential to further enhance the existing drone-based crocodilian monitoring method. Improvements in drone hardware, such as hybrid models with extended flight times and enhanced camera resolutions, allow for broader habitat coverage and the capture of more detailed imagery in complex environments. Integrating artificial intelligence (AI) represents a significant opportunity to streamline image analysis by automating crocodile detection and size estimation using allometric models. These AI-driven enhancements could provide near real-time data processing, reducing reliance on time consuming manual analysis.

This improvements are currently under development. We conducted an experimental study in Cameroon in April 2025 with students and young researchers from the University of Ngaoundéré and local NGOs, using drones equipped with thermal cameras and searchlights, and including AI-assisted automated data processing.

The data is currently being analyzed and will be published

4) Empowering Local Stakeholders through Drone Technology

This building block on capacity building on local stakeholders including Indigenous including Peoples and Local Communities (IPLCs) to operate drones, enabling them to take active roles in conservation. 

Ease of Use of the method devellopted:

  1. Minimal Technical Skills Required:
    Users only need basic training in drone operation and measurement extraction from high-resolution images. The process is straightforward:
    • Fly the drone following the standardized flight protocol.
    • Marke crocodilians on overhead images.
    • Measure the visible head length using accessible image analysis tools (e.g., ImageJ, QGIS).
    • Apply the corresponding allometric equation or lookup from pre-prepared tables (abaques) for total length estimation.
  2. Readily Adaptable:
    The framework uses easy-to-read tables (abaques), making it accessible to both specilialists and non-specialists for operators can quickly apply the method without requiring advanced scientific expertise.
  3. Accessible Equipment:
    The approach relies on consumer-grade drones and widely available software, ensuring affordability and reducing barriers to adoption.

Why It’s Effective:

The framework’s simplicity, scalability, and reliability make it ideal for diverse contexts, from remote wetlands to urban-adjacent habitats. It empowers a broad range of users to generate scientifically robust data.

3) Allometric Framework for Crocodilian Size Estimation

The allometric framework is a non-invasive tool designed to estimate the total body length of crocodilians based on the measurement of their head length, captured through high-resolution drone imagery. By leveraging established species-specific head-to-body length ratios, this method eliminates the need for physical capture or handling, reducing risks for both researchers and wildlife. Validated for 17 of the 27 crocodilian species, the framework allow to provides reliable demographic data essential for population monitoring and conservation management.

The framework uses easy-to-read tables (abaques), making it accessible to non-specialists, operators can quickly apply the method without requiring advanced scientific expertise.

2) Estimating total length of crocodylians from drone-captured images by using a model

Understanding the demographic structure is vital for wildlife research and conservation. For crocodylians, accurately estimating total length and demographic class usually necessitates close observation or capture, often of partially immersed individuals, leading to potential imprecision and risk. Drone technology offers a bias-free, safer alternative for classification. This study evaluated the effectiveness of drone photos combined with head length allometric relationships to estimate total length, and propose a standardized method for drone-based crocodylian demographic classification. 

An allometric framework correlating head to total length for 17 crocodylian species was developed, incorporating confidence intervals to account for imprecision sources (e.g., allometric accuracy, head inclination, observer bias, terrain variability).This method was applied to wild crocodylians through drone photography. Terrain effects were less impactful than Ground Sample Distance (GSD) errors from photogrammetric software. The allometric framework predicted lengths within ≃11–18% accuracy across species, with natural allometric variation among individuals explaining much of this range. Compared to traditional methods that can be subjective and risky, our drone-based approach is objective, efficient, fast, cheap, non-invasive, and safe.

1) Standardized Drone Survey Protocols

This building block establishes standardized flight parameters for effective crocodilian monitoring

Crocodiles can be closely approached (.10 m altitude) and consumer-grade drones do not elicit flight responses in West African large mammals and birds at altitudes of 40–60 m. Altitude and other flight parameters did not affect detectability, because high-resolution photos allowed accurate counting. Observer experience, field conditions (e.g. wind, sun reflection), and site characteristics (e.g. vegetation, homogeneity) all significantly affected detectability. Drone-based crocodylian surveys should be implemented from 40 m altitude in the first third of the day. Drone surveys provide advantages over traditional methods, including precise size estimation, less disturbance, and the ability to cover greater and more remote areas. Drone survey photos allow for repeatable and quantifiable habitat assessments, detection of encroachment and other illegal activities, and leave a permanent record. 
Overall,dronesofferavaluableandcost-effectivealternative forsurveyingcrocodylianpopulationswith compelling secondary benefits, although they may not be suitable in all cases and for all species

A & B. Demonstrative solar-powered electric fences and motion-sensor lights to mitigate predation; C. Cougar; D. Oncilla; E. Antonio jaguar (rediscoverd for the andean area of the Cauca Valle department) F.  Spectacled bear recorded by Camera trap
Development of a transdisciplinary plan for managing human–jaguar interactions at the regional scale in the DRMI Serranía de los Paraguas
Implementation of community-based monitoring of jaguars and ,mammal diversity using camera traps
Applying a behavior change approach to address human dimensions related to jaguars in strategic areas where the species is present
Implementation of adaptive livestock management strategies on farms adjacent to water source protection forests and public and private reserves
A & B. Demonstrative solar-powered electric fences and motion-sensor lights to mitigate predation; C. Cougar; D. Oncilla; E. Antonio jaguar (rediscoverd for the andean area of the Cauca Valle department) F.  Spectacled bear recorded by Camera trap
Development of a transdisciplinary plan for managing human–jaguar interactions at the regional scale in the DRMI Serranía de los Paraguas
Implementation of community-based monitoring of jaguars and ,mammal diversity using camera traps
Applying a behavior change approach to address human dimensions related to jaguars in strategic areas where the species is present
Implementation of adaptive livestock management strategies on farms adjacent to water source protection forests and public and private reserves
A & B. Demonstrative solar-powered electric fences and motion-sensor lights to mitigate predation; C. Cougar; D. Oncilla; E. Antonio jaguar (rediscoverd for the andean area of the Cauca Valle department) F.  Spectacled bear recorded by Camera trap
Development of a transdisciplinary plan for managing human–jaguar interactions at the regional scale in the DRMI Serranía de los Paraguas
Implementation of community-based monitoring of jaguars and ,mammal diversity using camera traps
Applying a behavior change approach to address human dimensions related to jaguars in strategic areas where the species is present
Implementation of adaptive livestock management strategies on farms adjacent to water source protection forests and public and private reserves
Drone crocodile surveys
West and Central Africa
North Africa
East and South Africa
Caribbean
Central America
South America
North America
Southeast Asia
South Asia
Oceania
Clément
Aubert
1) Standardized Drone Survey Protocols
2) Estimating total length of crocodylians from drone-captured images by using a model
3) Allometric Framework for Crocodilian Size Estimation
4) Empowering Local Stakeholders through Drone Technology
5) Evolution of on-board technologies and AI integration
Drone crocodile surveys
West and Central Africa
North Africa
East and South Africa
Caribbean
Central America
South America
North America
Southeast Asia
South Asia
Oceania
Clément
Aubert
1) Standardized Drone Survey Protocols
2) Estimating total length of crocodylians from drone-captured images by using a model
3) Allometric Framework for Crocodilian Size Estimation
4) Empowering Local Stakeholders through Drone Technology
5) Evolution of on-board technologies and AI integration