Sixty Years of Tinbergen’s Four Questions and Their Continued Relevance to Applied Behaviour and Welfare Research in Zoo Animals: A Commentary

Abstract

Understanding animal behaviour can feel like deciphering a foreign language. In 1963, pioneering ethologist Nikolaas Tinbergen offered a key: four fundamental questions to dissect behaviour’s complexities and reduce interpretive bias. These “Four Questions” fall into two categories: Proximate (how?) and Ultimate (why?). The Proximate questions ask how the behaviour is triggered (Causation) and develops over time (Ontogeny). The Ultimate questions delve into its evolutionary history (Phylogeny) and purpose (Function). Traditionally used in behavioural ecology, Tinbergen’s framework finds new relevance in fields like sentience, welfare, conservation, and animal management. This paper illustrates how further integration of these Questions into applied research can improve outcomes. For example, captive animals can receive enrichment seemingly “unnatural” in origin and form. Does such enrichment trigger species-typical behaviours, fulfilling the same adaptive function as natural stimuli would? Understanding a species’ natural behaviour patterns and how the performance of such activities promotes positive welfare states is key to biologically relevant population management. Tinbergen’s Four Questions can help scientists to decipher the relevance of natural behaviour, and how a species’ responses to their environment indicate what individuals need and want at a specific time or place. By applying the Four Questions, we can answer this question and, in turn, refine husbandry practices and conserve behavioural diversity in managed populations. Sixty years after their conception, Tinbergen’s Four Questions remain a powerful tool for behavioural research. By embracing different biological disciplines within a unified framework, applied animal zoo science will continue to advance and provide credible evidence-based outputs.