Measuring mantled howler monkey ( Alouatta palliata ) testes via parallel laser photogrammetry
Expanding the use of noninvasive methods
Bibliographic Data
Parallel laser photogrammetry (PLP), which consists of attaching two or three parallel laser beams at a known inter‐beam distance to a camera, can be used to collect morphological measurements of organisms noninvasively. The lasers project onto the photo being taken, and because the inter‐beam distance is known, they act as a scale for image analysis programs like ImageJ. Traditionally, this method has been used to measure larger morphological traits (e.g., limb length, crown‐rump length) to serve as proxies for overall body size, whereas applications to smaller anatomical features remain limited. To that end, we used PLP to measure the testes of 18 free‐living mantled howler monkeys ( Alouatta palliata) at La Selva Biological Station, Costa Rica. We tested whether this method could reliably measure this relatively small and globular morphology, and whether it could detect differences among individuals. We tested reliability in three ways: within‐photo (coefficient of variation [CV] = 4.7%), between‐photo (CV = 5.5%), and interobserver (intraclass correlation = 0.92). We found an average volume of 36.2 cm 3 and a range of 16.4–54.4 cm 3 , indicating variation in testes size between individuals. Furthermore, these sizes are consistent with a previous study that collected measurements by hand, suggesting that PLP is a useful method for making noninvasive measurements of testes
Biology · Intraclass correlation · Laser · Optics · Photogrammetry · Physics · Primate · Reproducibility · Statistics · Bat Biology and Ecology Studies · Computer Science · Mathematics · Morphological variations and asymmetry · Wildlife Ecology and Conservation · Anatomy · Artificial Intelligence · Ecology
Parallel lasers and digital photography to estimate limb size of chimpanzees (Pan troglodytes) at Ngogo, Kibale National Park, Uganda
A photogrammetric method to evaluate nutritional status without capture in habituated free-ranging Japanese macaques (Macaca fuscata)
Pandemic Human Viruses Cause Decline of Endangered Great Apes
Testis weight, body weight and breeding system in primates
A Guideline of Selecting and Reporting Intraclass Correlation Coefficients for Reliability Research
Application of a parallel laser apparatus to measure forearms and flanges of wild Bornean orangutans ( Pongo pygmaeus wurmbii )
Validation of two independent photogrammetric techniques for determining body measurements of gorillas
Growth trajectories in wild geladas ( Theropithecus gelada )
Observation of parturition in the Mexican mantled howler monkeys (Alouatta palliata) on the Island of Agaltepec, Veracruz State, Mexico
Ethical issues faced by field primatologists
Testing parallel laser image scaling for remotely measuring body dimensions on mantled howling monkeys ( Alouatta palliata )
Measuring physical traits of primates remotely
Darting Primates in the Field
Coupled social and ecological outcomes of agricultural intensification in Costa Rica and the future of biodiversity conservation in tropical agricultural regions
The Roles of Phytoestrogens in Primate Ecology and Evolution
Physiological and Behavioral Effects of Capture Darting on Red Colobus Monkeys (Procolobus rufomitratus) with a Comparison to Chimpanzee (Pan troglodytes) Predation
Primate Conservation
Impact of intrasexual selection on sexual dimorphism and testes size in the Mexican howler monkeys Alouatta palliata and A. pigra
Reproduction and population growth in free‐ranging mantled howling monkeys
Body growth and life history in wild mountain gorillas ( Gorilla beringei beringei ) from Volcanoes National Park, Rwanda
| Highly cited | No |
|---|