To escape humans, wild animals are massively changing their habits. But their precautions do not stop there: according to a study conducted by American researchers and published on June 15, 2018 in the prestigious journal Science, many mammals increase their activity during the night to escape the diurnal super-predator known as human.
The researchers used data from 76 previous studies of 62 mammal species on six continents. They then compared the behavior of animals subject to human proximity and those that are not. The results obtained are identical whatever the continent, the habitat or the species: when they can escape the human presence with difficulty, the animals choose to go out only when humans are in bed. Thus, nocturnal activities increase by a factor of 1.36 when living next to humans. “For example, an animal that shares its activities equally between day and night will increase its proportion of nocturnal activities to 68% of its total activity near anthropogenic disturbances,” note the researchers. Hunting, farming, road expansion… All forms of human presence, lethal or not for animals, increase their nocturnal activity. Humans would be perceived as a real threat regardless of his actions in the area.
If researchers agree that temporal avoidance may be a solution to avoid conflicts and facilitate a sometimes complicated coexistence, they also do not hide that it is not ideal. While some animals are perfectly adapted to a nightlife, others are currently unable to do so. They are less effective at finding food, avoiding predators or navigating in the middle of the night. This offbeat life also has ecological consequences: these animals reproduce less and see their life expectancy shorten. “Animal activities reflect millions of years of adaptation, and it’s hard to believe that we can simply push nature to activate at night and expect it to be functional and flourishing,” says Justin Brashares, co-author of the study.