According to a new study, more than one-quarter of the planet’s land vertebrates die because of humans. This is a “disproportionately huge effect” on the other land vertebrates that share planet’s surface with us.
Researchers from the SUNY College of Environmental Science and Forestry and the U.S. Department of Agriculture reviewed 1,114 published studies in which nearly 43,000 animals had perished. Their study, which was recently published in the journal Global Ecology and Biogeography, found that 28% of the animals’ deaths were directly attributable to humans. The other 72% died from natural sources.
Mammals, birds, reptiles, and amphibians that died between 1970 and 2018 in the Americas, Asia, Africa, Europe, and Oceania were the foundation of the study. All of these vertebrates had been either collared or tagged as part of other research projects.
The researchers point out that humans are only one among more than 35,000 species of terrestrial vertebrates globally. The fact that humans are responsible for more than one-quarter of their deaths illustrates the profound magnitude of the problem. And that statistic is just the direct causes. According to the researchers, when urban growth and other land use changes that erode habitat are considered, the human impact is likely even greater.
The study found that the impact of humans across all the different species was not equal. In fact, larger animals were more likely to be killed by humans than smaller animals. Adult animals were more likely to be killed by humans than juveniles.
The researchers conclude that humans are such a major contributor to terrestrial vertebrate mortality that they could potentially impact both evolutionary processes and ecosystem functioning.
Photo, posted March 6, 2019, courtesy of USFWS Midwest Region via Flickr.