Noninvasive collection of fresh hairs from free-ranging howler monkeys for DNA extraction

The use of noninvasive collected samples as source of DNA in studies of wild primate populations has increased in recent years. Fresh-plucked hairs represent an important source of DNA, with relatively high quality and concentration. In this study, we describe a low-cost noninvasive technique for collecting fresh-plucked hairs used to obtain DNA samples from free-ranging black howler monkey populations (Alouatta pigra). We designed and manufactured darts made of wooden dowels, with the anterior part smeared with glue, which were projected with blowpipes to trap howler monkey hairs. All of the materials to make the darts are inexpensive and are available locally. We collected 89 samples from 76 individuals residing in 15 troops, and the total number of hairs obtained was 754. We found no differences in the number of hairs collected among sex-age classes or among localities but the percentage of darts recovered with sample varied among localities. Preliminary results indicate that over 96% of samples yielded DNA suitable for polymerase chain reaction-based microsatellite marker analysis. The technique proved successful for collecting fresh-plucked hairs of free-ranging black howler monkeys without any trauma to the animals and can be easily adapted to obtain samples from other wild primate and mammal species.