Colour avoidance in northern bobwhites: effects of age, sex and previous experience

The effects of age, sex and previous experience on colour avoidance in northern bobwhites, Colinus virginianus , were evaluated. First, unlearned colour preferences were determined by measuring pecking by 52 1-day-old bobwhite chicks at pinheads of four colours. The number of first pecks and the total number of pecks varied significantly among colours ( P =0·011 and P green>yellow>red. There were no clear sex differences in pecking preference. A second experiment used a two-cup avoidance test to evaluate the effects of sex and previous experience on avoidance of coloured grain by juvenile bobwhite. Forty 11-week-old birds were pre-exposed for 7 days to either multi-coloured or undyed food, and then tested for 5 days for avoidance of red or blue food. Red food was avoided relative to undyed food (preference ratio=0·426, P =0·004), whereas blue food was not avoided. Sex of bird, pre-exposure to coloured food, and day of test had no significant effect on colour avoidance. Finally, 26 of the same birds were retested at the age of 31 weeks for avoidance of blue and red food. Results indicated no change in colour avoidance with age. Although these experiments failed to replicate a sex difference in colour avoidance that we found in a previous study, they did demonstrate that bobwhites show an unlearned aversion to red which is persistent and resistant to extinction. Because red is a common warning colour in insects, this aversion may be an adaptation for avoiding aposematically coloured prey.