In primates, complex object combinations during play are often regarded as precursors of functional behavior. Here we investigate combinatory behaviors during unrewarded object manipulation in seven parrot species, including kea, African grey parrots and Goffin cockatoos, three species previously used as model species for technical problem solving. We further examine a habitually tool using spe...

The widespread outbreak of psittacosis in man in 1929-30 led to renewed interest in the disease which quickly resulted in the discovery of the facts that the causative agent is not Nocard's bacillus but a filterable virus (1) and that the incidence of laboratory infections is high. Because of these facts it became imperative that further work on the nature of the etiological agent and the mode ...

How does brain size and design influence the survival chances of a species? A large brain may contribute to an individual’s success irrespective of its detailed composition. I have studied the size and shape of cerebella in birds and looked for links between the bird’s cerebellar design, brain size and behavior. My results indicate that the cerebellum in large-brained birds does not scale unifo...