Molecular Identification of Unknown Yellowstone Shrews

One of the challenges of conducting ecological and biodiversity studies on living organisms is the presence of many cryptic species, species that are difficult to identify based on external characters, or species that are difficult to see or trap. Identifying these challenging species is easier with current technology. Molecular techniques can allow us to identify and distinguish unknown specimens or animal parts based upon genes alone. One of these groups of cryptic species, shrews, has a big impact on our ecosystem because they feed on large quantities of invertebrates and play an important role in the food web; however, understanding and quantifying that impact requires correct species identification. Their small body-size and cryptic morphological characters means that there are many unidentified shrews in biological collections. We examined unknown tissues from shrews from sites in the Greater Yellowstone Area, and used DNA barcoding to determine species identity by comparing sequences to known species in the region. Based on this work, we show that the majority of shrews from our sample area are Sorex monticolus, and a minority are Sorex cinereus, suggesting that out of the 8 species in the region only two are predominant on our study site.