We present a noninvasive sampling approach to efficiently collect hair samples from elusive small mammals, as shown for the American pika. We demonstrate the utility of this method by extracting DNA from sampled hair and amplifying several types of molecular markers commonly used in studies of wildlife ecology and conservation.
Noninvasive genetic sampling approaches are becoming increasingly important to study wildlife populations. A number of studies have reported using noninvasive sampling techniques to investigate population genetics and demography of wild populations1. This approach has proven to be especially useful when dealing with rare or elusive species2. While a number of these methods have been developed to sample hair, feces and other biological material from carnivores and medium-sized mammals, they have largely remained untested in elusive small mammals. In this video, we present a novel, inexpensive and noninvasive hair snare targeted at an elusive small mammal, the American pika (Ochotona princeps). We describe the general set-up of the hair snare, which consists of strips of packing tape arranged in a web-like fashion and placed along travelling routes in the pikas’ habitat. We illustrate the efficiency of the snare at collecting a large quantity of hair that can then be collected and brought back to the lab. We then demonstrate the use of the DNA IQ system (Promega) to isolate DNA and showcase the utility of this method to amplify commonly used molecular markers including nuclear microsatellites, amplified fragment length polymorphisms (AFLPs), mitochondrial sequences (800bp) as well as a molecular sexing marker. Overall, we demonstrate the utility of this novel noninvasive hair snare as a sampling technique for wildlife population biologists. We anticipate that this approach will be applicable to a variety of small mammals, opening up areas of investigation within natural populations, while minimizing impact to study organisms.
Noninvasive genetic sampling has become an attractive alternative to traditional live trapping methods for several reasons. First, by unobtrusively collecting biological material (e.g., feces, hairs, feathers, saliva and mucus) from wild populations, researchers can study these species without disturbing, handling, or even observing them, thus reducing risks to both animals and researchers. Second, noninvasive genetic sampling enables biologists to study populations of elusive and rare species, a task that can prove difficult with more traditional live-trapping approaches 6. And third, NGS can potentially increase sample sizes by reducing disturbance to animals, sampling efforts, and costs, thus helping to minimise biases in estimates of population parameters 7. This latter point may prove crucial when dealing with threatened species, since biased estimates of population parameters may result in inappropriate management.
In the present video article we describe a simple, novel, inexpensive and noninvasive method to sample elusive small mammals, using the American Pika as an example. We demonstrate that DNA extracted from hair performs similarly to DNA extracted from liver samples with respect to microsatellite, AFLP, mitochondrial and sexing markers, making this noninvasive sampling method an attractive alternative to live trapping or lethal sampling. Overall, we anticipate that this method will be useful in the data collection stage of population genetic and behavioural studies of rare or elusive small mammal species, while minimizing impact on the organisms under study.
The authors have nothing to disclose.
We would like to thank L. Evans, B. Granger, D. Rissling, Z. Sim, A. Goodwin, K. Hayhurst and D. Kuch for assistance in the field. K. Galbreath kindly provided pika liver samples from the Bella Coola valley. Thanks to A. Gonçalves da Silva and K. Larsen for interesting discussions that contributed to the design of this noninvasive genetic sampling method. This work was funded by the Natural Sciences and Engineering Research Council of Canada Discovery, and UBC Okanagan Individual Research grants to MAR. A Swiss National Science Foundation Doctoral Fellowship PBSKP3_128523 supported PH. This study was undertaken following the animal care protocol from the University of British Columbia (Certificate number: A07-0126).
Hair snare:
DNA extraction: