Executive Summary

Outdoor recreation opportunities and participation have grown markedly in recent decades and the effects of recreation on wildlife behavior, fitness, and populations is a growing conservation concern. Numerous literature reviews of outdoor recreation effects on wildlife have been produced in recent years, with the rapidly growing body of scientific literature demonstrating that recreation may affect wildlife at the individual, population, and community level. Recreation can impact wildlife in numerous ways and varies depending on the interaction of numerous variables, including wildlife species, habitat type, and recreational activity. As a result, targeted, local scientific review of wildlife-recreation research is needed to mitigate potential negative effects of recreation on wildlife and encourage coexistence. This is particularly important for the western United States, which holds both the largest percentage of public lands and protected wildlife habitat, and is experiencing some of the highest population growth rates. 

Washington State has the second largest population in the West (7.7 million people and growing), and its primary metropolis, Seattle, has consistently been one of the fastest growing cities in the country. Washington holds myriad unique ecoregions, diverse wildlife communities, and remarkable opportunities for recreation; features that highlight the importance of a holistic understanding of the connections between wildlife and recreation. This report aims to provide a species-specific synthesis of recreation impacts for animals in Washington that are of interest to Conservation Northwest and reveal how animals may be responding to locally important types of recreation. The scope of this report is focused on the effects of year-round, terrestrial motorized and non-motorized recreational activities on terrestrial mammal and bird species. For each species we have summarized the relevant body of literature on specific recreation impacts and conclude with a discussion of both areas for future research and special recreation coexistence considerations in Washington. We aim to collate Washington-specific knowledge gaps to aid conservation practitioners in identifying and protecting habitat that supports robust wildlife populations, while still accommodating outdoor recreation activities. 

The majority of the literature identified for review in this report documented short-term behavioral changes and patterns of spatial and temporal displacement of wildlife in response to recreational disturbance. Wildlife responses to recreation were abundantly negative, yet few studies relate these responses to the species fitness, abundance, or distribution of wildlife populations. Our findings support the broad scale wildlife-recreation trends and patterns that have been discussed in other reviews, and we identified key areas where conservation practitioners in Washington can focus management and policy efforts. These include identifying the extent of wildlife-recreation overlap, measuring the thresholds at which varying levels of recreation intensity affect wildlife populations, protecting critical spatial and temporal refugia from recreation, and implementing management actions to mitigate recreation impacts. Across these key areas we highlight the following areas of focus:

• Identifying wildlife-recreation overlap in Washington

  • Mapping and modeling the extent of Washington’s recreation footprint with species ranges to identify overlap and priority areas to focus wildlife-recreation coexistence efforts. 

• Measuring recreation intensity and frequency

  • Prioritizing data collection at recreational areas across the state that can be used to quantify timing, frequency, magnitude, predictability, locations, and areas of recreation influence.

  • Pairing recreation intensity levels with species-specific thresholds of tolerance to prioritize and direct management strategies on a fine scale.

• Protecting spatial and temporal refugia

  • Protecting critical habitats that serve as spatial refugia from recreational development. This is especially important for wide-ranging umbrella species that are sensitive to disturbance and have specific habitat requirements. 

  • Carefully planning for future recreational development with a focus on concentrating recreation impacts to lower-quality habitats for vulnerable species and consolidating trail networks to limit habitat fragmentation and the spatial footprint of recreation.

  • Encouraging recreationists to consolidate use to developed recreation areas and reduce their overall recreation footprint. 

  • Reducing road densities through wildland areas by decommissioning select roads and limiting the construction of new roads.  

  • Maintaining temporal refugia for species that can adjust their behavior to avoid peak periods of recreational use, such as nighttime closures of high-use trail networks. 

  • Seasonally closing and/or restricting off-road and off-trail use in important reproductive or over-wintering areas to limit disturbance to species of interest during vulnerable seasons and life history phases (e.g., mule deer winter range, wolverine denning habitats).

•  Implementing management actions

  • Using information from the literature and mapping efforts as baselines for adaptive management studies.

  • Employing adaptive management practices to implement on the ground actions that work towards conservation goals even in situations where limited data is available.

Conservation practitioners need wildlife-recreation information summarized at a local scale to best manage recreation, advocate for effective policy, and protect habitat that supports robust wildlife populations while still accommodating outdoor recreation activities. As human populations continue to grow, wildlife increasingly face human-induced challenges that impact their persistence and survival. This may be especially important for Washington species that are particularly sensitive to disturbance, including threatened and endangered species, such as Canada lynx, grizzly bear, sage-grouse, marbled murrelet, wolverine, bighorn sheep, and mountain caribou. Outdoor recreation impacts are a piece of this larger puzzle, and the recent increases in outdoor recreation participation highlight an urgent and immediate need to both better understand and mitigate recreational impacts on wildlife. The information within this report provides a starting point for practitioners seeking to limit biodiversity loss and encourage wildlife-recreation coexistence into the future.