Together with Tindale, in field-work over 1938–39 in the Cairns rainforest, he concluded that the Indigenous "pygmy" peoples there, which they collectively called Barrineans, belonged to a group that were genetically distinct from the majority of Australian Aboriginal peoples, perhaps related to the Aboriginal Tasmanians.
[2] After teaching briefly at the State College of Washington, he served as an Army Air Corps officer in World War II.
He taught anthropology at UCLA from 1948 until his retirement in 1974, continuing his research, and writing many articles and a widely used textbook on human evolution.
[8] Birdsell was awarded a Guggenheim Fellowship in 1946, and several of his field seasons in the Australia were financed by the Carnegie Corporation.
[8] Early scholars had tended to view the peopling of Australia as the result of three separate waves of immigration, with distinct human types.
[10] In a recent polemic, Keith Windschuttle and Tom Gittin observed that the model had dropped from view, and attributed political motives to its disappearance off the popular and academic radar.
[13] In his seminal paper of 1977, "The recalibration of a paradigm for the first peopling of Greater Australia", he examined the standard models for the origins of Aboriginal Australians regarding how human migration from Southeast Asia could cross the Sahul barrier.