Humans are really good at killing things, especially, as new research shows, large birds of the Pacific.
Fossil records show that, as humans migrated to new land masses, we tended to kill off the big meaty things we found.
The research, published in the Proceedings of the National Academy of Sciences Monday, sought to estimate just how many species of birds went extinct in the Pacific region as humans spread out from mainland Asia onto the multitude of islands in the massive ocean.
The study was led by author Richard Duncan of the University of Canberra, and focused on large, nonpasserine birds in the eastern Pacific, specifically those on 41 of the 269 larger islands of the region. Passerines are birds that perch, like songbirds. The nonpasserine birds in the study were large (like New Zealand’s moa), meaning that their plump bodies were attractive prey to early humans, and that fossils from their larger bones were much easier to find.
Many of these birds lived in environments without major predators, meaning the invading humans could make easy meals of the birds, which led to their overhunting and eventual extinction.
The study estimated that, according to ScienceNow, “at least 989, and as many as 1300 nonpasserine land bird species went extinct across the Pacific islands as human civilization took root there.” Those numbers mean that, as humans spread across the Pacific, we killed off about 10 percent of the bird species of the world.
How did we kill them off? Hunting was a big factor (those big, defenseless birds were tasty), but clearing away the species’ habitats to make room for our burgeoning agriculture also accounted for a lot of the die-off. As Duncan pointed out, “when you don’t have chainsaws and things, the easiest way to clear forest is to set it on fire.”