International research tandems and co-

To facilitate global collaborations, strengthening of international research structures, capacity building and global learning, the TREES project as solution strongly builds on international partnerships. The team itself is composed in most of the countries of international research tandems, whereby PhD and Master students originate from the country of study as well as Germany or other country. Whilst each student has his/her individual research focus, data collection is planned and implemented in the binational tandems. Supervision is provided in international supervision tandems whereby in each country a university is taking the country lead and co-supervision is provided by the project lead organization.  

Setting up binational research teams contributes toward enhanced complexity thinking through integration of multiple perspectives and disciplines. This facilitates research on FLR implementation for enhanced analysis and solution development as well as capacity building and global learning through North-South and South-South collaborations. Joined field visits can facilitate students’ access to study sites, interaction with actors on the ground, and increased samples sizes if questionnaires are combined. 

Establishing international PhD and Master student research tandems and building international co-supervision teams opens up new learning spaces and opportunities for collaborations. Different expertise and perspectives can be integrated in the different PhD and Master Thesis study projects, research design and implementation. Diversified research methods can be implemented in a complementary way to deepen FLR related analysis and combined interpretation perspectives enrich research output. If questions on data arise or verification is needed upon completion of the field trip, the tandem structure facilitates follow up field visits for complementation or verification of results. Knowledge derived and communicated via multiple channels in Germany and the F4F countries can enhance dialogue at the policy, practice, science interface within and across countries. 

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

Methodology
  • Involvement of the local community
  • Responding to community needs 

The openness of the community to learn and adopt the toolkit.

The financial support for the project.

The effectiveness of the toolkit in deterring the wildlife from farms. 

Unlocking future impact: Funding and professional development

For many conservationists, including our participants, the knowledge to effectively use conservation technology is not enough without the funding to access the tools. Recognizing this barrier, we provide each participant with USD$500 in seed funding to support the implementation of their conservation solutions. Participants are required to propose and carry out projects, which have ranged from building predator-proof bomas and underwater camera traps to developing AI tools, mobile apps, and community-driven citizen science initiatives. Each participant is required to report on their project’s progress over the following year, fostering accountability and impact tracking.

To ensure long-term sustainability, we also deliver training in grant writing, proposal development, and funder engagement to equip participants with the skills needed to secure sustained future funding. Ongoing mentorship and support also continue beyond the initial training. Our team, along with a growing alumni network, provides guidance on grant applications, reference letters, and professional development opportunities. Many of the projects and collaborations initiated during the program have led to graduate study, published research, and conference presentations, reinforcing participants’ continued growth as conservation leaders. 

  • Support from donors who fund seed grants
  • Ongoing dedication and investment of trainers and mentors
  • Students are required to submit two updates and a financial report for their grant. Ensuring follow-up on these submissions requires dedicated effort and engagement from the core team 
  • Students have reported that being able to list the seed funding received through our program on their CVs has helped them secure additional funding opportunities in the future.
Focusing on hands-on engagement

Our technical training emphasizes experiential learning by giving participants direct, practical experience with conservation technologies. Whenever possible, students are encouraged to set up and deploy tools themselves in safe, low-pressure environments, creating space to experiment, make mistakes, and learn by doing. For instance, students may choose camera trap locations based on the classroom training module, then evaluate the effectiveness of their decisions by analyzing the resulting data. This process helps bridge theory and practice while building confidence in problem-solving and tool use.

In cases where participants cannot operate the tools directly, trainers and field practitioners from host institutions provide live demonstrations, such as tracking wildlife using GPS or operating drones, ensuring students still gain exposure to how these technologies function in real-world conservation settings.

  • Access to technology tools at host institution for practical use 
  • Opportunities for students to trial and test tools themselves
  • Experience instructors to provide guidance and support 
  • When paired with supporting background information, we have found these hands-on experiences to be more impactful than traditional lectures or merely observing technology in use 
  • Providing opportunities to engage with the entire lifecycle of a technology (e.g., from set up and deployment to data collection and analysis) better prepares students for using these technologies in their own projects
Strengthening early career potential

We select participants who are at the beginning stages of their careers, such as those who have completed their bachelor’s degrees and are entering the NGO or conservation workforce or embarking on higher education.The goal is to identify participants whose careers would benefit the most from the type and amount of training, funding, mentorship, and support we provide. Over the past two years, we’ve recruited at least one participant from a non-academic background who nevertheless possesses extensive on-the-ground experience. These individuals have thrived in the program, highlighting an opportunity to further cater to this audience in future iterations.

  • Strong networks with local academic institutions and regional NGOs help us attract a large pool of qualified applicants (~200 applications per year)
  • Tailored educational materials that align with the needs of early-career participants
  • Community of same-stage participants form strong and enduring connections 
  • Initially, we included participants at various career stages, but we found that older, more experienced individuals have different needs and require a distinct program tailored to their experience level
  • Our entry-level training materials were less useful for women with more experience in the field