The "biological annihilation" of wildlife in recent decades means the sixth mass extinction in Earth's history is under way and humans are to blame, according to research.
The study, published in the peer-reviewed journal Proceedings of the National Academy of Sciences, overlooks the current trends of population declines and extinction.
Using a sample of 27,600 terrestrial vertebrate species - such as mammals, birds, reptiles and amphibians - and a more detailed analysis of 177 mammal species, the study shows the extremely high degree of population decrease in vertebrates.
According to Gerardo Ceballos, study co-author and Ecology professor at the National Autonomous University of Mexico, 30 per cent of the evaluated species are losing populations.
Researchers blame human overpopulation and overconsumption for the crisis as well as what they call the "massive anthropogenic erosion of biodiversity and of the ecosystem," that threatens the survival of human civilisation itself, highlighting the seriousness of the situation.
Ceballos said the window to act is very short and if this does not happen, a large amount of species will be lost in about 100 or 150 years.
Ceballos has called for an international institution was needed to fund global wildlife conservation. If this trend continues, Ceballos added, at the end of the century, 70 per cent of these species would be lost, with man being the main culprit.