Abstract
To establish longevity of faecal DNA samples under varying summer field conditions, we collected 53 faeces from captive brown bears (Ursus arctos) on a restricted vegetation diet. Each faeces was divided, and one half was placed on a warm, dry field site while the other half was placed on a cool, wet field site on Moscow Mountain, Idaho, USA. Temperature, relative humidity, and dew point data were collected on each site, and faeces were sampled for DNA extraction at <1, 3, 6, 14, 30, 45, and 60 days. Faecal DNA sample viability was assessed by attempting PCR amplification of a mitochondrial DNA (mtDNA) locus (∼150 bp) and a nuclear DNA (nDNA) microsatellite locus (180–200 bp). Time in the field, temperature, and dew point impacted mtDNA and nDNA amplification success with the greatest drop in success rates occurring between 1 and 3 days. In addition, genotyping errors significantly increased over time at both field sites. Based on these results, we recommend collecting samples at frequent transect intervals and focusing sampling efforts during drier portions of the year when possible.
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Acknowledgments
We would like to thank the following people for laboratory assistance and protocol optimization: Christine Cegelski, Christine Clarke, Carol Perugini, Jeffrey Stetz, and Dr. Samuel Wasser. For use of laboratories and field sites we thank Dr. Steve Brunsfeld, Dr. Rodney Mead, and Dr. Ed Krumpe. We especially thank Dr. Charles Robbins for use of the captive brown bear facility at Washington State University. We also thank Jeffrey Evans for helpful comments on drafts of this paper. Finally, we thank two anonymous reviewers, whose generous comments greatly improved this manuscript.
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Murphy, M.A., Kendall, K.C., Robinson, A. et al. The impact of time and field conditions on brown bear (Ursus arctos) faecal DNA amplification. Conserv Genet 8, 1219–1224 (2007). https://doi.org/10.1007/s10592-006-9264-0
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DOI: https://doi.org/10.1007/s10592-006-9264-0