A comparison of genetic and field methods for assessing capercaillie abundance

Abstract

Capercaillie Tetrao urogallus abundance was estimated from genetic and field methods in a forest in Strathspey, Scotland. Genetic methods prior to application of capture-mark-recapture techniques over-represented males by 6–15% relative to lek attendance, gave contrasting results between years relative to males seen on brood counts, and under-represented females by 82% and 173% at leks and on brood counts, respectively. A CMR genetic-based model for males only estimated about twice as many males as on lek or brood counts. Of the 33 males identified by genetic methods in 2014, only four (12%) were detected 2 years later. We conclude that our genetic sampling effort needed doubling to provide accurate population estimates.