Timing Moose Pellet Collections to Increase Genotyping Success of Fecal DNA

Fecal pellets can serve as a noninvasive source of DNA for identifying the distribution of individual animals when conducting population estimates. The quality of fecal DNA, however, can be degraded by wet or warm environmental conditions. We tested the effect of time of pellet collection (mid-March-mid-June) and temperature on the success of genotyping microsatellite loci in moose Alces alces by using DNA extracted from moose fecal pellets collected from north central British Columbia, Canada. Using the number of microsatellite loci genotyped as a measure of genotyping success clearly indicated that fecal pellets collected in March and April contained DNA that yielded high-confidence genotypes, whereas those collected in May and June did not. Pellets collected in March and April were more likely to be collected in cooler (often subzero) temperatures than those collected in May and June. Pellets collected later in the year were also more likely to be exposed to rain and increased solar radiation, all of which are likely to contribute to degradation of fecal DNA. Our findings suggest that pellets collected in late winter in the Northern Hemisphere have sufficient DNA to permit genotyping of moose.