Grey parrot (Psittacus erithacus) numerical abilities: Addition and further experiments on a zero-like concept
A Grey parrot (Psittacus erithacus), able to quantify 6 or fewer item sets (including heterogeneous subsets) by using English labels (I. M. Pepperberg, 1994), was tested on addition of quantities involving 0-6. He was, without explicit training, asked, “How many total X?” for 2 sequentially presented collections (e.g., of variously sized jelly beans or nuts) […]
Ordinality and inferential abilities of a grey parrot (Psittacus erithacus)
A grey parrot (Psittacus erithacus), able to label the color of the bigger or smaller object in a pair (I. M. Pepperberg & M. V. Brezinsky, 1991), to vocally quantify < or =6 item sets (including heterogeneous subsets; I. M. Pepperberg, 1994), and separately trained to identify Arabic numerals 1-6 with the same vocal English […]
Concept formation in American black bears, Ursus americanus
Despite their large relative brain size, bears have been neglected in studies of comparative cognition in comparison to their fellow carnivores, the social canines and pinnipeds. Here, three captive adult American black bears were presented with a series of natural concept discrimination tasks on a touchscreen computer, in which the discriminations varied in degree of […]