Fig. 1. Modelling kidnapping behaviour with a multi-state approach in the emperor penguin. States 1 and 2 are, respectively, the non-kidnapping state and the kidnapping state. ^ab is the transition probability from state a to state b over one post treatment day (t) to the next one (t+1). ¹² is the probability that a penguin will kidnap a chick from t to t+1. (1–S) is the probability that a bird will leave the colony from t to t+1. P and (1–P) are, respectively, the probabilities that a bird present on the colony in one of the behavioural state was seen or not during the daily scan.