Title
Measuring physical traits of primates remotely: The use of parallel lasers
Author(s)
Rothman, J.M.; Chapman, C.A.; Twinomugisha, D.; Wasserman, M.D.; Lambert, J.E.; Goldberg, T.L.
Published
2008
Publisher
American Journal of Primatology
Published Version DOI
https://doi.org/10.1002/ajp.20611
Abstract
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. © 2008 Wiley-Liss, Inc.
Keywords
arboreal species; behavioral ecology; body size; comparative study; digital photogrammetry; field method; growth rate; laser; life history; morphology; morphometry; national park; primate; remote sensing; animal; animal disease; article; Colobinae; comparative study; evaluation; histology; laser; methodology; morphometrics; photography; tail; Uganda; Animals; Body Weights and Measures; Colobus; Lasers; Photogrammetry; Tail; Uganda; Africa; East Africa; Kibale National Park; Sub-Saharan Africa; Uganda; Western Province [Uganda]; Animalia; Colobinae; Colobus sp.; Mammalia; Primates; Procolobus badius; Procolobus rufomitratus; Field measurements; Laser metrics; Remote measurements

Access Full Text

A full-text copy of this article may be available. Please email the WCS Library to request.



Back

PUB10496