A study has revealed the early stages of Earth's 6th mass extinction event, for which human activities are being held responsible.
The biologists from Stanford University have cautioned that, since 1500, more than 320 terrestrial vertebrates had become extinct and the populations of the remaining species showed a 25 percent average decline in abundance.
Rodolfo Dirzo, the lead author, explained the era of "Anthropocene defaunation", where elephants and other large animals were facing an increased risk of extinction, which could be associated to human activity.
Dirzo said that where human density was high, there were high rates of defaunation, high incidence of rodents, and thus, high levels of pathogens, which increased the risks of disease transmission.
The scientists also detailed a troubling trend in invertebrate defaunation, which showed that human population had doubled in the past 35 years; in the same period, the number of invertebrate animals, such as beetles, butterflies, spiders and worms, had decreased by 45 percent.
Dirzo further added that ironically, people had long considered that defaunation is a cryptic phenomenon, but they would end up with a situation that is non-cryptic because of the increasingly obvious consequences to the planet and to human wellbeing.