Measuring physical traits of primates remotely

The use of parallel lasers

Bibliographic Data

ID19386238
AuthorsJessica M Rothman (0000-0002-7664-6065, McGill University, corresponding author), Colin A Chapman (0000-0002-8827-8140, Wildlife Conservation Society), Dennis Twinomugisha (Kibale Chimpanzee Project), Michael D Wasserman (0000-0003-1611-024X, University of California, Berkeley), J E Lambert (0000-0002-2849-3930, University of Wisconsin–Madison), Tony L Goldberg (0000-0003-3962-4913, University of Illinois Urbana-Champaign)
Year2008
Volume70
Issue12
Pages1191-1195
Publication date2008-12-01
Open AccessYes
TypeARTICLE
VenueAmerican Journal of Primatology (JOURNAL)
Journal identifiersISSN: 0275-2565 • E-ISSN: 1098-2345
PublisherWiley (PUBLISHER • GB)
DOI10.1002/ajp.20611
PMID18767123
OpenAlexW2115372696
LanguageEN
Citations received18
References cited10

Physical traits, such as body size, and processes like growth can be used as indices of primate health and can add to our understanding of life history and behavior. Accurately measuring physical traits in the wild can be challenging because capture is difficult, disrupts animals, and may cause injury. To measure physical traits of arboreal primates remotely, we adapted a parallel laser technique that has been used with terrestrial and marine mammals. Two parallel lasers separated by a known distance (4 cm) and mounted onto a digital camera are projected onto an animal. When a photograph is taken, the laser projections on the target provide a scale bar. We validated the technique for measuring the physical traits of identifiable red colobus monkeys ( Procolobus rufomitratus ) in Kibale National Park, Uganda. First, we photographed the tails of monkeys with laser projections and compared these with measurements previously obtained when the animals were captured. Second, we manually measured the distance between two markers placed on tree branches at similar heights to those used by monkeys, and compared them with the measurements obtained through digital photographs of the markers with parallel laser projections. The mean tail length of the monkeys via manual measurements was 63.3±4.4 cm, and via remote measurements was 63.0±4.1 cm. The mean distance between the markers on tree branches via manual measurements was 13.8±3.59 cm, and via remote measurements was 13.9±3.58 cm. The mean error using parallel lasers was 1.7% in both cases. Although the needed precision will depend on the question asked, our results suggest that sufficiently precise measurements of physical traits or substrates of arboreal primates can be obtained remotely using parallel lasers. Am. J. Primatol. 70:1191–1195, 2008. © 2008 Wiley‐Liss, Inc

Arboreal locomotion · Biology · Habitat · Laser · Optics · Physics · Primate · Animal Behavior and Reproduction · Animal Vocal Communication and Behavior · Mathematics · Primate Behavior and Ecology · Ecology

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