Discrimination learning and extinction in the black rhinoceros (Diceros bicornis)

Dallas zoo - Diceros bicornis . These rhinos have a large, common enclosure and individual pens. Since the experiments were carried out in the individual pens, only these will he described. The pens were 21 x 16 ft. with a door of heavy bars between the pen and common enclosure. There were three openings between the 'I' beams at the front of the pen. Each opening was 40 in. long x 17 in. high.

A seven-year-old black rhinoceros from the Ft. Worth Zoo was the only S [subject] used for the preliminary work.

The Ss in Experiments 1-3 were a male and a female black rhinoceros in the Dallas Zoo. The female is estimated to be nine years old and the male three years old.