The effects of novel odour and colour cues on food acceptance by the zebra finch, Taeniopygia guttata

Studies on domestic chicks Gallus gallus domesticus, have shown an advantage of multimodal advertisement by prey species. An interaction of novel colour and novel odour cues creates a synergistic aversive reaction (that is, the effect of the two cues presented simultaneously is greater than predicted by their individual presentation). Such reactions have not been tested empirically with passerine species, which account for about 60% of all bird species. We investigated the reactions of a passerine model, the zebra finch to novel colour and novel odour cues within food by measuring latencies to make contact with and to eat it. Zebra finches showed a synergistic reaction towards a combination of novel colour (red) and novel odour (pyrazine) cues despite showing no reaction to novel odour alone. As domestic chicks behave similarly, our results reveal that avian predators from different families show the same behaviour and suggest it might be a general behaviour of all birds. A comparison of the contact and consumption latencies for food of novel colour, and food of novel colour and odour, found that contact latencies remained the same while consumption latencies increased. We propose this is evidence of independent regulation of the processes controlling contact with a novel food (neophobia) and consumption of that food (dietary conservatism). (C) 2004 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.