Historical Avifaunal Change and Current Effects of Hiking and Road Use on Avian Occupancy in a High Latitude Tundra Ecosystem

Abstract

Tourism is increasing in tundra ecosystems across the world, yet its influence on bird communities and its interaction with other drivers of change is poorly known. To help fill this gap, we paired an interview-based survey of eleven people with local knowledge of Denali National Park and Preserve, with an occupancy study of 15 bird species in relation to road proximity, traffic volume, and hiking. Interviewees noted declines in American Golden Plover, Arctic Tern, Long-tailed Jaeger, and Northern Wheatear over the past five decades. Our occupancy study confirmed these reports as we detected no Arctic Terns, few Northern Wheatears, and found both plovers and jaegers to be sensitive to hiking. Occupancy of tundra and shrub habitats by American Golden Plover, American Tree Sparrow, Lapland Longspur, Long-tailed Jaeger and Willow Ptarmigan declined with increasing hiking intensity. We found that occupancy probability of tundra by Horned Lark increased, while that of the shrub-tolerant Wilson’s warbler decreased, with distance from the Park Road. Detection of species varied based on survey length, noise, start time presence of a trail, and date. The knowledge gained from this study reveals a loss in avian diversity over the past few decades that has the potential to cause a shifted baseline syndrome, and ongoing threats of hiking to sensitive tundra-breeding birds. Park managers should seek to balance human recreation with the needs of sensitive tundra-breeding birds to further protect species of conservation concern. This may be done by not building new trails in tundra, limiting access to tundra hiking areas during the early breeding season, reducing the spatial extent of hiking by improving maintained trails and designating a single, maintained path in areas with multiple unofficial hiking tracks, educating tourists about tundra nesting birds, and closing especially important nesting areas to the public.