It's no big surprise that humans are impacting the planet. But a new study pinpoints a sobering connection. 

As human life expectancy increases, so does the percentage of invasive and endangered birds and mammals, according to a study by the University of California, Davis.

The study, published in the September issue of Ecology and Society, examined a combination of 15 social and ecological variables — from tourism and per capita gross domestic product to water stress and political stability. Then researchers analyzed their correlations with invasive and endangered birds and mammals, which are two indicators of...