smaller:
shorter length & wingspan
males 82g-125g
females 144g-208g

larger:
longer length & wingspan
males 297g-380g
females 460g-588g

smaller, rounded
shaped head

squarer shaped head

uniform dark gray
crown and nape

cap: lighter nape than crown
(juvenile shown)

yellow supraorbital
ridge skin

gray supraorbital
ridge skin

long thin leg

leg thicker

white terminal band
on tail is narrow

white terminal band
on tail is wide
(may be worn off)

square tail
(some females have
rounded tail)

rounded tail