Animals Need Commute Routes in Human Habitats

To get from his house on the eastern side of the St. Lawrence River to his lab at Montreal’s McGill University on the flanks of the city’s namesake Mount Royal, Andrew Gonzalez has an easy commute. He takes a subway line that runs beneath the river, and then he walks or bikes from the station to the university. Sometimes, though, during the roughly 30-minute trip, he imagines what it might be like for another species to travel through this environment. Could a rabbit make the journey? A salamander? A deer?

Gonzalez thinks a lot about this sort of thing. An ecologist who studies the causes of biodiversity loss and how to prevent them, he has spent much of his career researching landscape connectivity—the degree to which animals are able to move within and between patches of habitat. Every species has a daily and seasonal pattern of movement, and distinct methods of crisscrossing a landscape to find food, water, shelter, and mates. But the myriad ways humans have sliced up, paved over, and otherwise radically reorganized Earth’s terrain impact species’ ability to get where they need to go to survive. Now, climate change is raising the stakes while throwing up new obstacles: Some species will need to migrate increasingly long distances to find suitable homes. One recent study found that in the United States, only 41 percent of existing “natural” areas are sufficiently connected to enable species to follow the environmental conditions they need.