A direct comparison of scan and focal sampling methods for measuring wild chimpanzee feeding behaviour

Ian Gilby, Amy A. Pokempner, Richard W. Wrangham

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

Focal sampling is the most accurate method for measuring primate activity budgets but is sometimes impractical. An alternative is scan sampling, in which the behaviour of the group is recorded at regular intervals. The simplest technique is to record whether at least 1 animal is engaged in the behaviour of interest. By direct comparison with focal data collected simultaneously on the same population, we assess the validity of this simple group level sampling method for studying chimpanzee (Pan troglodytes schweinfurthii) feeding behaviour. In a 13-month study at Kanyawara, Kibale National Park, Uganda, group level scan sampling provided statistically similar measures of broad diet composition to those produced by focal data, despite considerable seasonal variation. Monthly means of the percentage of time spent consuming non-fig fruit calculated from group level scan sampling were highly correlated with those from focal sampling. This validates previous methodology used to identify periods of high energy availability. However, group level scans tended to overestimate the percentage of observation time spent feeding, particularly for adult males. We conclude that this method of group level scan sampling provides valuable data for characterizing broad diet choice in chimpanzees and other species, but may be of limited use for estimating individual feeding time.

Original languageEnglish (US)
Pages (from-to)254-264
Number of pages11
JournalFolia Primatologica
Volume81
Issue number5
DOIs
StatePublished - Jan 2011
Externally publishedYes

Fingerprint

feeding behavior
Pan troglodytes
sampling
methodology
diet
individual feeding
group behavior
activity pattern
Uganda
method
comparison
measuring
primate
national parks
Primates
national park
seasonal variation
fruit
fruits
animal

Keywords

  • Activity budget
  • Diet
  • Field methods
  • Focal sampling
  • Frugivory
  • Pan troglodytes
  • Scan sampling

ASJC Scopus subject areas

  • Animal Science and Zoology
  • Ecology, Evolution, Behavior and Systematics

Cite this

A direct comparison of scan and focal sampling methods for measuring wild chimpanzee feeding behaviour. / Gilby, Ian; Pokempner, Amy A.; Wrangham, Richard W.

In: Folia Primatologica, Vol. 81, No. 5, 01.2011, p. 254-264.

Research output: Contribution to journalArticle

Gilby, Ian ; Pokempner, Amy A. ; Wrangham, Richard W. / A direct comparison of scan and focal sampling methods for measuring wild chimpanzee feeding behaviour. In: Folia Primatologica. 2011 ; Vol. 81, No. 5. pp. 254-264.
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