one green planet
one green planet

Thanks to medical advances, people are living longer these days. Yet while humans enjoy longer lives, the number of endangered birds and mammals is increasing. These two ideas might not seem correlated at first but according to new research out of the University of California (UC), Davis, increased human life expectancy can be linked to a rise in endangered species as well as invasive species.

The study was recently published in the journal Ecology and Society and was authored by Aaron Lotz of UC Davis and Craig Allen of the Nebraska Cooperative Fish and Wildlife Research Unit.

According to Nature World News, the study included 100 countries that accounted for nearly 87 percent of the world’s population, 43 percent of global gross domestic product (GDP) and 74 percent of the Earth’s land.

Together, the researchers examined a combination of 15 social and ecological variables including tourism, per capita GDP, water stress, and even political stability of the 100 countries. They then took these variables and analyzed how the figures correlated with invasive and endangered species numbers (birds and mammals, in particular).

Surprisingly, human life expectancy, which is rarely included in studies focused on human impact on the environment, came out on top as a key predictor of global invasions and extinctions, reports UC Davis via a press release about the study.

“It’s not a random pattern,” said Lotz. “Out of all this data, that one factor — human life expectancy — was the determining factor for endangered and invasive birds and mammals.”

The U.S., the Philippines, and New Zealand had the highest percentage of endangered and invasive birds while African countries had the lowest percentage, the study found.

“Some studies have this view that there’s wildlife and then there’s us,” said Lotz. “But we’re part of the ecosystem. We need to start relating humans to the environment in our research and not leave them out of the equation. We need to realize we have a direct link to nature.”

Image source: USFWS Endangered Species / Flickr