DUET SONGS OF THE SIAMANG, HYLOBATES SYNDACTYLUS: II. TESTING THE PAIR-BONDING HYPOTHESIS DURING A PARTNER EXCHANGE

The aim of this study was to understand the relationship between production of food calls by maternal hens and both food quality and social context. Nineteen broody hens were tested in twenty experiments combining four different food contexts with five social situations in which they could receive different levels of stimuli from their chicks. Results revealed that the food call rates of broody hens were positively correlated with food quality (or motivational state with regard to food). They were also influenced by the callerʹs social context: presence of chicks, behaviour of chicks and separation from chicks modified food call production. These results are therefore consistent with previous reports on food calling by cockerels.