Indirect effects of bioinvasions in Yellowstone Lake: The response of river otters to declines in native cutthroat trout

摘要: Abstract Nonnative species threaten ecosystems throughout the world — including protected reserves. In Yellowstone National Park, river otters Lontra canadensis depend on native cutthroat trout as prey. However, nonnative lake and whirling disease have significantly reduced abundance of these fish in park's largest body water, Lake. We studied demographic behavioral responses to declining Lake its tributaries. From 2002-2008, we monitored otter activity at latrine (scent-marking) sites, collected scat for prey identification, used individual genotypes from hair samples evaluate survival with capture–recapture methods. Otter latrines decreased declines trout, prevalence declined 73% 53%. Cutthroat numbers were best predictor temporal variation apparent survival, mean annual was low (0.72). The density our study area (1 per 13.4 km shoreline) also low, evidence a recent genetic bottleneck suggests that might prior study. River around appear be responding reductions via changes distribution, diet, possibly abundance. Our results provide baseline estimate monitoring broader outcome management efforts conserve emphasize indirect ecosystem consequences invasive species.