Hair Snares for Noninvasive Sampling of Felids in North America: Do Gray Foxes Affect Success?

Hair‐snare sampling has become a popular technique to assess distribution and abundance of felids. Using standard hair‐snaring protocols, we sampled for margays ( Leopardus wiedii ) in Mexico and mountain lions ( Puma concolor ) in California, USA, without success. However, we noted a preponderance of gray fox ( Urocyon cinereoargenteus ) hair at sampling stations. Our review of recent literature suggests a pattern of failure to detect target felids in hair‐snare surveys conducted within the range of the gray fox. We propose, among several alternative explanations, that marking by gray foxes interferes with the tendency of felids to face‐rub at sampling stations.