Sexual Dimorphism in Captive Bred Gallicolumba luzonica Individuals from Avilon Wildlife Conservation Foundation by Breast Patch Size Measurement

Breast patch size measurement as a method of determining sexual dimorphism between Gallicolumba luzonica individuals was tested. 11 G. luzonica individuals (5 males, 6 females) were obtained and photographed. Calibrated with a 5-peso coin, patch size (PS) and patch size with wash (PSW) was measured in the photograph using Image J. Morphometrics (total length, snout to vent length, wing span, tail length, head length, culmen length, and tarsus length) were also measured. Univariate analysis and Shapiro-Wilk normality tests were done to determine distribution of data for each parameter. Pearson Correlation Coefficient analysis between PS, PSW and morphometric measurements was done to test if the size of the bird is a factor for the size of breast patch. Lastly, t-test was done to determine significant statistical difference of PS and PSW between male and female G. luzonica individuals. Results show that data on all parameters are normally distributed. Also, bird size (morphometrics) was not seen to be correlated to PS and PSW. However, t-test show no statistical difference between male and females for both PS and PSW. These data suggest that patch size measurement may not be a determinant of sexual dimorphism between G. luzonica individuals, disabling us to assess Mr. Macapagal's accuracy in sex determination of G. luzonica. It is suggested that a larger sample size be obtained in order to yield a more reliable statistical data.