Gerard LeBlond for redorbit.com – Your Universe Online
Waterfowl such as ducks, geese and swans belong to the order Anseriformes. Game birds such as pheasants, partridges, hens and turkeys are known as the order Galliformes. The birds belonging to both of these orders are recognized not only for their meat, but also for the elegant display of their plumage.
Some members within the orders show differences between male and female, known as sexual dimorphism. Such as with the mallard, the male and female plumage is so different that for years they were thought to be a separate species altogether. However, in some species, various members of the same order show little difference between the two sexes.
Thanh-Lan Gluckman, a Cambridge PhD candidate, has researched this phenomenon and published her findings in the Biological Journal of the Linnean Society. She notes the similarities and differences in the plumage of almost 300 members of both orders – focusing mainly on the patterning between male and female instead of the color.