Radiocarbon dating service

No evidence was found for biases in atmospheric 14C levels due to fossil-derived or industrial CO2 contamination. We document methods for narrowing resolution to one age range, including stratigraphic analysis of vegetation collected from pika haypiles. The two-sided nature of the bomb curve renders far- and near-side dates of equal probability, which are separated by one to four decades. We resolved calibrated dates with high precision (within several years), most of which fell in the period of the mid-late 20th century bomb curve. Carbon was extracted from pellets collected at 43 locations in the western Great Basin, USA, including three known occupied sites and 40 sites of uncertain status at range margins or where previous studies indicated the species is vulnerable. We explored the value of radiocarbon dating of fecal pellets to address questions of population persistence and timing of site extirpation. The American pika ( Ochotona princeps) has become a species of concern for its sensitivity to warm temperatures and potential vulnerability to global warming.