CHAFFINCH (FRINGILLA COELEBS) EPAULETTE DISPLAY DEPENDS ON THE DEGREEOF EXPOSURE BUT NOT SYMMETRY OF INTRUDERS EPAULETTES

1. Epaulettes, white wing patches, are exposed in agonistisc displays between territorial chaffinch males. 2. As with many bilateral traits one should expect that asymmetrical development of the two wing patche s could indicate poorer individual. Therefore it is likely that territ ory owners change their display toward asymmetrical competitor. 3. We tested the effect of exposure and symmetry of epaulettes of a stuffed bird on epaulette exposure of the territorial male. The results showed that: 4. males increased the degree of their epaulette exposure in re sponse to larger epaulette on the mount; 5. males did not respond to t he asymmetry of epaulettes on the mount. 6. The results aggree with th e interpretation that the males' display of exposed epaulettes to each other could be regarded as communication. The epaulette display could be a signal of high aggressive motivation in the chaffinch.