Social facilitation of drinking of a partially satiated duckling

Water-deprived and nondeprived ducklings were reintroduced to a flock companion which had been allowed to partially satiate itself after 3 h of water deprivation. The drinking and sieving behavior of the partially satiated "reactor" bird was immediately increased above that of similar birds left on their own. However, whether or not the introduced "actor" ducklings were deprived had no consequences for the drinking response of the reactor above that obtained by their introduction. The number of companions introduced also failed to have any effect other than that obtained by their introduction. The increase in sieving was greater when deprived, rather than nondeprived, actors were introduced. These results were discussed in relation to the motivational aspects of sieving behavior and the mechanism of social facilitation.