An investigation of quantity discrimination in Clark's nutcrackers (Nucifraga columbiana).

Academic Article


  • We examined quantity discrimination in the Clark's nutcracker (Nucifraga columbiana), a corvid bird with a strong dependence upon caching and recovering nuts. We presented 2 sets of nuts simultaneously, in 21 different conditions, to see if the nutcrackers could choose the larger of the 2 quantities. The nutcrackers displayed a strong ability to discriminate quantities of nuts. Like other animals tested previously, the nutcrackers' performance decreased as the ratio of the 2 quantities approached 1. Interestingly, at constant distances, the nutcrackers did not have more difficulty with contrasts containing larger quantities. Thus, nutcrackers have a fine sensitivity for discriminating between 2 quantities. We review the relevant literature and explore the possibility that nutcrackers, like some other birds, may have developed a keen ability to discriminate quantities. This ability may have developed as an adaptive specialization to cope with their scatter-hoarding ecology, though the evidence for such a conclusion is mixed.
  • Authors

  • Tornick, Jan
  • Callahan, Emily S
  • Gibson, Brett
  • Status

    Publication Date

  • February 2015
  • Published In


  • Animals
  • Animals, Wild
  • Behavior, Animal
  • Discrimination, Psychological
  • Mathematical Concepts
  • Passeriformes
  • Digital Object Identifier (doi)

    Pubmed Id

  • 25150963
  • Start Page

  • 17
  • End Page

  • 25
  • Volume

  • 129
  • Issue

  • 1