A major six-year study published in Science finds that the simple presence of people changes how wild animals use landscapes, in addition to the effects of habitat loss. The global collaboration involved Yale researchers and colleagues from more than fifty academic and governmental organisations, and was led by Ruth Oliver and Scott Yanco. Walter Jetz of Yale said the findings add an important nuance to our understanding of wildlife in a rapidly changing world.
Scientists combined GPS tracking of 37 species across the United States with mobile phone data and satellite-derived measures of human disturbance. The team collected about 11.8 million location points from over 4,500 animals, including white-tailed deer, wolves, coyotes, raccoons, skunks, several big cat species, vultures, hawks, ducks, cranes and storks. Mobile device data made estimates of human presence possible during the COVID-19 pandemic, and changes in movement during 2020 helped separate human presence effects from long-term landscape change such as urbanisation and agriculture.
More than 65% of species changed behaviour when people were present, and responses varied by species and place: many reduced their used area while others expanded it. For example, gray wolves expanded their range, ravens covered more ground, and coyotes tended to restrict movements. Individual animals also showed year-to-year flexibility. The authors note habitat loss remains the main driver of biodiversity decline, but direct human use of landscapes also matters.
The study recommends that conservation planning consider where and when people are present and adopt targeted actions rather than one-size-fits-all solutions. Possible measures include:
- limiting traffic at key times,
- reducing disturbance in sensitive habitats,
- tailoring strategies to each place and species.
Difficult words
- presence — being in a place at a given timehuman presence
- habitat — natural home or environment of a specieshabitat loss, sensitive habitats
- disturbance — a human action that disrupts animal activityhuman disturbance
- urbanisation — process of land becoming towns and cities
- biodiversity — variety of living species in an areabiodiversity decline
- conservation — planned actions to protect nature and speciesconservation planning
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Discussion questions
- Do you think using mobile phone data to estimate human presence in wild areas is acceptable? Why or why not?
- How could conservation actions differ for species that expand their range compared with those that restrict movements?
- What practical challenges might planners face if they limit traffic at key times to reduce disturbance?
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