ABSTRACT
Tinamous are an ancient family of birds, thought to be closely related to ratites. They superficially resemble chickens and other gallinaceous birds, but have several structural differences, including a thinner bill and a raised or absent hind toe. Tinamou feathers are unique in that they are "joined" together rather than "hooked" by barbs as in most birds, and it is this structure that is believed to be responsible for the noticeable whistling noise tinamous produce during flight. A preformative molt is said to initiate soon after fledging, before the body fully grows into the adult size, progresses rapidly, and is complete, which people confirmed in an examination of Tinamus and Crypturellus specimens at Louisiana State University Museum of Natural Science (LSUMZ). Females average larger than males, but there is extensive overlap, and plumage differences are often subtle and may vary more among subspecies than between sexes.
