Behavioural responses of blue petrel chicks (<i>Halobaena caerulea</i>) to food-related and novel odours in a simple wind tunnel

Abstract

As a first step towards understanding the development of olfactory behaviours in Antarctic procellariiform seabirds, we recently showed that blue petrel chicks ( Halobaena caerulea ) could detect both a food-related and a novel odour while asleep. In this current study, we tested chicks in a simple wind tunnel to determine if exploratory behaviours could be initiated by olfactory stimuli as well. We compared the behavioural responses of 30 blue petrel chicks to cod liver oil (a prey-related odour) or phenyl ethyl alcohol (an unfamiliar, rosy-smelling odourant) against a control (distilled water). Six behavioural indices were measured, including head turns, body turns, bites, preening events, wing-stretches, and distance walked. In response to cod liver oil, we found that chicks increased both turning rates and distances walked whereas chicks preened more in response to phenyl ethyl alcohol. Since only cod liver oil initiated behaviours consistent with searching, our results suggest that chicks are attaching biological significance to food-related odours even before they leave the burrow to forage for the first time.