Behavioural reactivity testing in sheep indicates the presence of multiple temperament traits

Temperament Behaviours in Individually Tested Sheep Are Not Related to Behaviours Expressed in the Presence of Conspecifics

“…However, their stability across situations requires further exploration. In a previous study, we confirmed the repeatability of vocalisations over time under different testing conditions involving three response-eliciting stimuli [ 10 ]. This indicated the presence of a domain-general temperament trait which we labelled sociability, defined as the response to either the presence or absence of conspecifics [ 2 ].…”

“…This study used the same three behavioural tests and measures of temperament and reactivity as Atkinson et al [ 10 ] and repeated these tests under two different social conditions: in the absence and presence of conspecifics. Each lamb was tested once individually (IND) and once with three other conspecifics (GRP) which occurred over two consecutive days.…”

“…GRP testing consisted of the human and startle tests only (see Table 1 for behaviours measured). This test was used to measure human-directed fear responses and was based on a modified version of a forced approach test [10,19] with an additional modification. As a moving human could prompt highly reactive lambs to sprint across the arena and jump against the walls, this study used a stationary human to ensure the safety of both the lambs and the human.…”

Exposure to humans after weaning does not reduce the behavioural reactivity of extensively reared Merino lambs

“…Three months after the current study the same group of lambs completed a second round of testing in the MH, S and IB tests for a related, but separate study (Atkinson et al, 2022). For ease of modelling, both rounds of data were modelled together, and this process has been described.…”

“…Though this may require complicated bootstrapping approaches in frequentist models, it is a natural result of Bayesian analysis (Bürkner and Vuorre, 2019). The joint model structure allowed in the 'brms' package (Bürkner, 2017) also allowed the specification of correlated subject parameters between responses, which is explored elsewhere (Atkinson et al, 2022).…”