A NEW METHOD OF DETERMINING OVENBIRD AGE ON THE BASIS OF RECTRIX SHAPE

Understanding age-specific differences in life history characteristics depends on accurate assessment of age. Use of rectrix shape for aging Ovenbirds (Seiurus aurocapillus) as HY/SY or AHY/ASY individuals was investigated using a macroscope, videocamera and image analysis softwa re to analyze rectrix tip angles of 82 birds of known age. AHY/ASY bir ds had significantly larger tip angles than HY/SY birds and were corre ctly classified over 90% of the time. This method of quantifying rectr ix shape it as time efficient and accurate.