Treating Japanese quail with vitamin C does not facilitate their capture by the experimenter

Abstract

1. Vitamin C supplementation reduces fear of novel situations and of people. The present study examined its effects on the ease of capture of male Japanese quail by the experimenter. 2. At 20 d of age, quail received either vitamin C (ascorbyl-2-polyphosphate, APP , 1 g L-ascorbic acid/l) solution or untreated drinking water (UDW) for 24 h before they were mixed in 2 groups of 40 (20 APP + 20 UDW). All the birds in 1 group were caught individually by an unsighted experimenter whereas a sighted catcher captured the others. The bird's identity was noted each time. This capture/recapture procedure was repeated 6 times for each group (12 capture trials per bird) and an overall capture rank across all 12 trials was assigned to each bird. 3. Regardless of whether the catcher was sighted or unsighted, the mean ranks of neither APP nor UDW quail differed significantly from the value expected by chance. Neither were there any linear trends in the effects of repeated testing. Thus, prior treatment with vitamin C neither facilitated nor hindered capture. 4. Body weights were similar in both treatment groups and there were no significant intra-individual correlations between body weight and capture rank. 5. Highly significant tendencies were found for individual birds to be caught at similar stages of each capture trial regardless of treatment or test situation. This finding sounds a cautionary note for all studies involving putatively random sampling of a population.