Data from: Investigating variation in third-party intervention behavior during a fallow deer (Dama dama) rut

Pairwise contests are frequently disrupted by the intervention of
third-party group members. However, little is known about whether an
individual’s engagement in intervention behavior varies over time, or what
factors might be associated with such variation. Using a hierarchical
“hurdle” model with 2 levels, we investigated the conditions under which
focal males: 1) would or would not engage in an intervention, and 2)
varied the number of interventions per day they engaged in. The lower
level of the model showed that the proportion of unique opponents per day
(estimated from the overall number of mature males in the herd) that focal
males competed with, and the number of interventions suffered by a focal
male were associated with an increased probability that this individual
would itself engage in third-party intervention behavior. At the upper
level of the model, there was no association between these 2 variables and
the rate at which individuals engaged in intervention behavior. The number
of matings observed per day and aggression rate within the herd failed to
contribute meaningfully to either level of the model. We also show that,
although inconsistent over days and between years, some individuals
displayed a greater propensity to intervene than others. The data from our
study show that intervention behavior is more likely to occur as a result
of individual directly experiencing aggressive behavior at a sufficiently
high level, and not as a result of individuals monitoring aggressive or
sexual activity in the wider social group.