Changes in Testosterone and Corticosterone Profiles in Stone Magpie Birds under Songbird Contest Condition

A previous study illuminated the influence of testosterone hormone and stress on bird songs, with the stress response being measured by their corticosterone levels. Since the data about Stone Magpie testosterone and corticosterone levels during songbird competition remains unreported, this study aims to investigate testosterone and corticosterone hormone levels in Stone Magpies before and after the songbird contest. Fecal samples were collected from twelve birds, distinguishing between amateur and experienced groups, both before and after the songbird contest, and preserved at -20°C. Corticosterone and testosterone hormone levels were assessed using an ELISA kit, and the acquired data were tested for normal distribution and homogeneity, followed by analysis through the T-test method. The results indicated an increment of testosterone and corticosterone hormones among experienced Stone Magpie
birds after the contest; however, these changes did not reach statistical significance. The mean values, both before
and after the contests, of testosterone levels in the amateur group did not show a significant difference. However,
corticosterone levels in this group showed significant differences (P<0.05), with post-contest levels being higher than pre-contest. In the experienced group of Stone Magpie birds compared to the amateur group, the values of testosterone
hormone showed higher results both before and after the contest. On the other hand, the corticosterone levels were
lower than the amateur group, both before and after the contest. However, the statistical test did not indicate the
significance of this difference. From the findings, it can be concluded that amateur birds were more stressed under the
songbird contest whereas the experienced group displayed better performance, which may be related to their increased
testosterone levels after the contest. However, our study did not show a direct relation between testosterone and
corticosterone levels in Stone Magpie birds with their contest experience.