Wildlife's varied response to human presence

A new study tracking 4,581 individual mammals and birds across the continental United States has found that the physical presence of people reshapes wildlife movement and habitat use. The research, led by scientists from UC Santa Barbara, the Smithsonian's National Zoo and Conservation Biology Institute, and Yale University, was published in the journal Science in August 2026.

According to the source, the study combined GPS tracking data from 37 animal species with anonymized cellphone geolocation data. This allowed the team to separate the influence of human presence from the effects of permanent landscape changes like roads and cities. Co-lead author Ruth Oliver, an assistant professor at UCSB, stated that humans have complicated effects on wildlife and that understanding the full impact requires information on both factors.

The Pandemic Provided a Unique Experiment

COVID-19 lockdown policies created a rare opportunity for researchers. The dramatic shift in human movement during 2020 allowed scientists to compare animal GPS records from matching periods in 2019 and 2020. Scott Yanco, a co-lead author from the Smithsonian, explained that the anonymized cellphone data used was made available to researchers during the pandemic. He noted this was a rare opportunity, as such data is typically held by private companies.

The team examined how human activity affected both the physical area used by each animal and its environmental niche. For most species, human impacts could not be fully understood by looking at landscape modification alone. The presence of people also mattered.

Species Showed Divergent Responses

The research found no universal wildlife response to human influence. Instead, reactions differed substantially by species and depended on how heavily a landscape was already altered.

Overall, 57% of the species studied were affected by both human presence and landscape modification. Human presence was associated with changes for 67% of mammal species and 68% of bird species. About 67% of mammal species and 41% of bird species responded to the combination of both factors by reducing the amount of habitat they used. Sensitivity to people was especially strong in places with relatively little development, such as national parks.

Implications for Conservation and Future Research

The findings are part of the COVID-19 Bio-Logging Initiative, an international effort that assembled 1 billion location records from roughly 13,000 animals. Oliver highlighted the critical importance of species-based conservation, noting that every species has different requirements and faces unique threats.

The researchers are now examining whether the behavioral changes they observed are helping animals adapt or are a sign of stress. Oliver pointed out that the current study shows animals change how they use space, but it is not known if these changes increase or decrease their risk of dying. She expressed optimism that more nuanced policies, which smartly consider where and when to give animals space, could achieve better wildlife coexistence.