As has been mentioned in these dispatches previously, the planet is now in the early stages of its sixth mass extinction event, and humans are indeed responsible, according to yet another published study, this one in Science. According to the study, large vertebrate animals (megafauna), which include elephants and polar bears, face the steepest decline since they require large habitats and are targeted by human hunters. The loss of megafauna places ecosystems off balance and leads to consequences like massive rodent infestations that proceed to impact the well-being and stability of a large segment of species, including humans. The study highlights how the particularly steep decline of megafauna we are seeing now is characteristic of all the previous mass extinction events.