Behavioural profiles of African bovids (Hippotraginae)

Behavioural assays for taxon-specific groups aid in assessing individual welfare and in population planning important to ensure sustainability (e.g. choice of enclosures, age/sex structure of groups, candidates for breeding and reintroduction). Personality approaches to measuring individual variation include ethological coding and subjective ratings via keeper questionnaires. We report on an ethological coding technique for measuring behavioural traits under conditions where individuals are in large social groups in semi-natural enclosures with minimal keeper contact. This standardised quantitative approach augments a questionnaire used by decision-makers in choosing appropriate candidates for breeding. This case study was conducted at a conservation breeding centre that is part of a network of institutions managing sustainable herds of ungulates with the long-term goals of recovery, reintroduction and ecological restoration. We developed a behavioural assay system for the subfamily Hippotraginae (African horse antelope) based on ethological coding of video samples. We field-tested this system using focal observations of social behaviour of breeding males in two herds, one each of addax (Addax nasomaculatus) and sable (Hippotragus niger). We demonstrated how behavioural profiles can be tested for significant differences in the categories of general activity, subcategories within each activity and indicator behaviours within each subcategory. This type of information is needed to develop a long-term database to test the additive effects of multiple variables (age, sex, rearing conditions, group, enclosure, population and species) on variation in individual profiles. We discuss the utility of coding video samples to validate subjective scoring techniques, statistical approaches to assessing variability in individual behaviour profiles, and the value of a hierarchical nested approach to analyse behavioural categories. We recommend applying this evolutionary ecology framework when designing behavioural assay systems, especially for species managed for recovery and reintroduction in sustainable populations.