Figure 6. Species-specific functional responses to human footprint in US national parks (2019−2020). Predicted relationship between the mean human footprint in an individual animal’s home range and its avoidance/selection of the human footprint, estimated separately for each species and year. Sample sizes indicate the number of individual-years per species. A slope of zero indicates that animals exhibit a consistent response to the human footprint, regardless of how much of it is in their home range. A negative slope indicates sensitivity to human disturbance, as animals with more footprint in their home range increasingly avoid footprint (or select for it less). A positive slope indicates habituation to human disturbance, as animals with more footprint in their home range avoid footprint less (or select for it more). In 2020, a positive slope may also indicate that animals selected more for the human footprint given the absence of humans in these areas. Note that both the x- and y-axis scales change across plots; the x-axis scales reflect the range of mean footprint values observed for each species. Species icons from PhyloPic.org
Press:
UBC Science, July 31, 2025: Wildlife show wide range of responses to human presence in U.S. national parks
Abstract
Given the importance of protected areas for biodiversity, the growth of visitation to many areas has raised concerns about the effects of humans on wildlife. In 2020, the COVID-19 pandemic led to temporary closure of national parks in the United States, offering a pseudonatural experiment to tease apart the effects of permanent infrastructure and transient human presence on animals. We compiled GPS tracking data from 229 individuals of 10 mammal species in 14 parks and used third-order hierarchical resource selection functions to evaluate the influence of the human footprint on animal space use in 2019 and 2020. Averaged across all parks and species, animals avoided the human footprint, whether the park was open or closed. However, although animals in remote areas showed consistent avoidance, on average those in more developed areas switched from avoidance to selection when protected areas were closed. Findings varied across species: some responded consistently negatively to the footprint (wolves, mountain goats), some positively (mule deer, red fox) and others had a strong exposure-mediated response (elk, mountain lion). Furthermore, some species responded more strongly to the park closure (black bear, moose). This study advances our understanding of complex interactions between recreation and wildlife in protected areas.