EEB267H1 Lecture Notes - Lecture 20: Uropygial Gland, Theropoda, Avialae
23 Mar 2017
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Document Summary
Birds are reptiles: no such thing as birds and repties . Birds are nestled within theropoda, which is within the dinosauria. Pennaceous feathers were found in some theropoda. Downy feathers are even older: difficult to study as they are light and fluffy, do not fossilize. Uropygial gland: at the base of the tail, bird dips beak into wax, and then spreads wax across the feathers. Gland produces wax esters: resistance to water, dirt, uv radiation keeps feathers flexible. Get damaged easily: dirt, flying, etc. Moulting feathers are periodically shed: no great trauma, new feathers push out old feathers ecologically diverse. Diet: herbivores, predators, nectar (and insects), fruit, carrion eaters, seed eaters. Habitat: warmblooded, can survive in the arctic and tropics and deserts, no fully aquatic birds reproductive biology. Only basal birds have a penis: e. g. , ostriches, ducks. All birds have internal fertilization: sperm is transferred via the cloacal kiss , penis has been lost within neornithes.
