Animal Ethics in Behavioral Studies—Advocating a Differentiated View

Animal behavior research has significantly advanced our understanding of animals as sentient, behaviorally complex, and often highly social beings. It has also deepened our knowledge of their needs and laid important foundations for how to treat them and their environments ethically and respectfully. It is paradoxical that bureaucratic hurdles and a political push to replace or drastically reduce animal experimentation now increasingly impede this research field. A group of established researchers working in the field of animal behavior covering topics from animal welfare, the consequences of individuality, chemical communication, and behavioral development has now highlighted the urgent need for a more nuanced perspective on animal experiments (Richter et al. 2025).

The debate between proponents, emphasizing the necessity of animal experiments in research, and opponents, raising animal welfare concerns, has led to entrenched positions and a polarized, black-and-white view of the issue. Close to 8 million animals are used in approved experiments across the European Union every year—comprising the ~7.5% being used in animal behavior studies, but also in a wide range of fields, from cancer research to drug testing and more. Here, at the latest, it should become obvious that animal experiments do not fit in just one drawer. They range from simply observing a fish swimming in a tank (a procedure with no burden to the animal) to attaching a small geolocator on a stork to understand its migration route, to conducting highly invasive procedures, for example, in testing cancer drugs or testing the safety of chemicals. While the severity (a measure to estimate the burden to the animals) of these examples greatly differs, all experiments are subject to the same rigorous and extensive ethical approval process. However, the vast majority of animal behavior and welfare studies impose at most only mild stress (the lowest of the severity classes) on the experimental animals. The authors therefore propose that the European severity classification of experimental procedures (Mild, Moderate, Non-recovery, and Severe) should also inform the permitting process, suggesting that lower severity levels correspond to expedited approvals (Richter et al. 2025). Our focus, like that of Richter et al. (2025), is solely on the European situation. However, expanding the discussion to include regulations and procedures in other countries and continents could provide valuable insights.

Placing behavioral research in one category with more intrusive investigations, and the rigorous permitting procedures attached to it, causes serious problems in the field of education: School teachers find it almost impossible to introduce their pupils to live animals and it becomes increasingly difficult—even at the university level—to teach the correct handling of animals to zoology students and to induce a healthy empathy with animals. This reduces the chances of future teachers and educators to propagate these skills and instill enthusiasm in their pupils. Bachelor and Master theses need to be planned far in advance because the bureaucracy involved in obtaining the necessary permits often takes so long that it becomes impossible to get them in time, thereby forcing students to search for alternative topics, using existing datasets or moving to different fields. One consequence of this, is an “extinction of experience,” as it was also just highlighted for field-based research, which usually face no smaller hurdles than studies placed in laboratories (Soga and Gaston 2025). Further, early career researchers who are often put on short-term contracts might barely get a chance to plan and conduct experiments that would be essential to secure the next position or grant, when they must wait easily 6–9 months for the approval of their experiments.

Animal behavior research contributes, for example, to building a basis for conservation action, understanding the implications of climate change, leading to improvements in animal welfare, including in livestock husbandry, and searches for solutions for the negative influence of human-made changes (expanding cities, increasing light at night, noise- and other pollution). Complex and time-consuming permit procedures for these non- to low-intrusive investigations, falling into the lowest severity class, severely constrain the opportunities for this kind of essential research. Recent discussions have even fueled the fear that this research could eventually come to a complete halt or be farmed out to countries with lower standards, should animal experiments (in every sense of it) one day be completely abolished. Another issue not addressed by Richter et al. (2025) is that the permitting process is not standardized and, at least in Germany, varies between permitting bodies and even from year to year. This inconsistency highlights a lack of a data- and science-based application of the severity classification by the permitting authorities. Rather than being grounded in state-of-the-art measurements that capture the animals' responses to certain procedures, like capture, handling, or tagging, the classification often relies on subjective opinions.

The publication by Richter et al. (2025) is by no means a call to lower animal welfare standards, but a call for a more nuanced view and practical solutions for behavioral research, allowing the effective teaching of and advancement in animal behavior and ecology, including animal welfare aspects. Improvements could start with more transparency and a better dialog with the public about requirements, reasonings, and purpose of such studies. Initiatives like the German program “Tierversuche verstehen—Eine Informationsinitiative der Wissenschaft” (Verstehen 2024) (translated as: “Understanding Animal Testing – An Information Initiative by the Scientific Community”), coordinated by an alliance of scientific organizations, exemplify proactive efforts to educate the public and provide fact-checking to combat myths and misconceptions surrounding animal testing. Additionally, the establishment of institutional expert committees for faster processing and differentiated approval pathways based on severity and purpose could further enhance the process while maintaining accountability and public trust.

By this publication (Richter et al. 2025), the authors have renewed an important debate about the differences among animal experiments and the urgent need for accordingly more sensibly differentiated permit procedures.

Hanja B. Brandl: conceptualization, writing – review and editing, writing – original draft. Fritz Trillmich: conceptualization, writing – review and editing, writing – original draft.