Abstract
The sex of 51 Great Cormorants Phalacrocorax carbo (23 males, 28 females) were determined by necropsy, and seven measurements from the skulls were recorded to develop a process by which to determine the sex of skull specimens. The seven skull measurements included the following:
LUM= Length from the tip of the beak to the frontonasal hinge
MIW= Minimum interorbital width
WPP= Width between the postorbital processes
MWCP= Maximum width of the cerebral prominence
WZP= Width between the zygomatic processes
WPPE= Width between the paroccipital processes at the posterior end
LS= Length of the skull
All measurements from necropsied males measured significantly longer than those of females. Skull measurements were calculated to identify the sex of unknown Great Cormorant skull specimens. Formulas for determining the sex of Great Cormorant skulls were:
Z= -0.9066xLUM+2.1497xLS+0.3386xMIW-214.5102
Z= -1.4283xLUM+2.5528xLS+3.2109xWPP-318.8841
Z= -1.1873xLUM+2.2508xLS+2.3136xMWCP-273.4371
Z= -0.7515xLUM+1.9100xLS+1.2840xWZP-232.7216
Z= -0.7419xLUM+2.0227xLS+0.6296xWPPE-222.9565
Z=0.5930xMIW+2.1102xWPP+1.8790xMWCP+1.9484xWZP+0.0079xWPPE-193.9309
