17-18 September 2025,  PollinERA project conducted a two-day hybrid workshop titled Pollinator Survival Modelling and Parameter Estimation with over 50 participants from research, industry and regulation attending.

The two-day workshop focused on the General Unified Threshold models for Survival (GUTS) and its extension, BufferGUTS, offering a practical introduction to Toxicokinetic-Toxicodynamic (TK/TD) models and its uses in Environmental Risk Assessment (ERA). These mechanistic models integrate exposure and effect dynamics in pesticide risk assessment, resulting in a process-based method for assessing consequences of chemical exposure across time. BufferGUTS applies the concept of GUTS models, which were originally developed for aquatic habitats with water as the primary exposure pathway, to terrestrial ecosystems, resulting in a major improvement in pollinator risk assessment.  It is a practical and approachable tool for researchers and regulators alike, as it encompasses a wide range of exposure pathways (oral, topical, and surface contact) and can be calibrated using simple toxicity test data.

The first workshop day was led by Florian Schunck (University of Osnabrück), focusing on understanding the survival models GUTS and BufferGUTS by getting to know the Python library mempyGUTS and parameter estimation with the open-source model-building platform pymob. Participants also interpreted model results and assessed model uncertainties with Bayesian methods.

On the second day, Andreas Focks (University of Osnabrück) and Florian Schunck promoted discussion, interpretation, and strategic application of models in ERA, as well as the possibility to integrate survival models with other types of modelling, such as ecological models.

The participants expressed a significant interest in learning how the models might be used to relate lab results to real-world circumstances. During the discussions, a need for testing and validating models, as well as providing simple, easy-to-use tools to help researchers plan experiments, collect relevant data, and generate estimates was emphasised. The session also discussed future approaches for using BufferGUTS in ERA, such as investigating species differences, analysing combination stressors, and measuring more subtle or long-term effects on pollinator populations.