One of the key challenges in assessing animal welfare is that mental experiences cannot be measured directly. However, by measuring indicators within each physical/functional domain, researchers can cautiously infer the associated negative or positive mental experiences.

This study offers a new approach to assessing the welfare of free-roaming wild horses, and provides scientific validation for a range of indicators that can be used to infer the mental experiences of wild horses. The researchers used the Five Domains Model, a contemporary framework for assessing animal welfare. This model is based on the understanding that physical and mental states are linked. It consists of four physical/functional domains (Nutrition, Physical Environment, Health, and Behavioral Interactions) and a fifth domain representing mental experiences.

The study identified and validated indicators for a range of negative mental experiences in free-roaming horses. These include thirst and hunger, linked to low body condition score and limited access to water or food; temperature discomfort, indicated by sweating and shivering along with environmental conditions; various types of pain associated with specific indicators such as wounds or lameness; breathlessness, linked to increased respiratory rate and effort; and social isolation, indicated by lack of close spatial proximity with other horses and minimal affiliative interactions.

The research also validated indicators for positive mental experiences. These include pleasure associated with drinking and eating, comfort from appropriate temperatures, vitality from good health and fitness, and enjoyment from social interactions. This focus on positive experiences supports a more holistic approach to animal welfare that considers not just the absence of suffering, but also the presence of positive experiences.

The study introduced a new category of indicators called “quasi-welfare status” indicators. These are resource-based measures that have a strong scientific link to animal-based welfare status. For example, the availability of water sources can be used as a quasi-welfare status indicator for thirst when direct observation of drinking behavior is not possible in wild animals.

The researchers also distinguished between “welfare status” indicators, which reflect current mental experiences, and “welfare alerting” indicators, which warn of potential future welfare risks. This distinction allows for more nuanced and proactive welfare assessments. The authors emphasize that the strength of evidence linking an indicator to a mental experience should be reflected in a confidence score. This approach ensures transparency and acknowledges the varying degrees of certainty in welfare assessments.

The study has significant implications for animal welfare science and practice. It provides a scientifically robust method for assessing the welfare of free-roaming wild horses, which can be challenging to observe closely. What’s more, the framework developed can be adapted for use with other wild species, potentially revolutionizing wildlife welfare assessments. By validating indicators of both negative and positive mental experiences, the research supports a more holistic approach to animal welfare. The distinction between welfare status and welfare alerting indicators allows for both immediate assessment and future risk mitigation.

This study marks a significant advancement in our ability to assess and understand the welfare of free-roaming wild horses. By scientifically validating a framework for inferring mental experiences from observable indicators, the research opens up new possibilities for improving the lives of these animals. The framework distinguishes between “welfare status” indicators, which reflect current mental experiences, and “welfare alerting” indicators, which signal potential future risks. This distinction allows for both immediate assessments and proactive risk mitigation, offering a more comprehensive approach to animal welfare.

For animal advocates and policymakers, the research provides valuable tools for assessing and monitoring the welfare of wild horse populations. The emphasis on positive mental experiences reinforces the importance of ensuring that animals not only avoid suffering but also have opportunities for pleasure and satisfaction. The framework could inform decisions regarding the management of wild horse populations, ensuring that welfare considerations are prioritized. Furthermore, the approach has the potential to improve welfare assessments across a range of wild species, enhancing conservation and wildlife management efforts.

Despite these advances, challenges remain in applying these indicators to free-roaming wild horses, particularly in situations where close observation is not possible. Further research is needed to refine these methods, possibly incorporating technologies like remote cameras or drones for distance monitoring. Nonetheless, this study represents a major step forward in animal welfare science, with the potential to transform how we assess and manage the welfare of wild animals, contributing to the broader field of conservation welfare.