Of all the birds left in the world, 70 percent are poultry chickens and other farmed birds, a study says.
It says humans occupy a tiny space when it comes to planet Earth.
The weight of all 7.6 billion humans makes up just 0.01 per cent of all biomass on Earth, according to a report published in the Proceedings of the National Academy of Sciences on Monday, copied to the Ghana News Agency.
It said bacteria, by comparison, make up 13 per cent of all biomass, plants account for 83 per cent, and all other forms of life make up 5 per cent of the total weight, according to the report.
Despite being such a small part of the planet, humans have been steadily destroying everything else for the past few millennia, the report says.
In fact, humans have caused the annihilation of 83 per cent of all wild mammals and half of all plants, the authors of the report found.
And it’s not just that humans are wiping out wildlife — they’re also determining the animals and plants that remain.
Of the birds left in the world, 70 per cent are poultry chickens and other farmed birds. And of the mammals left in the world, 60 per cent are livestock, 36 per cent are pigs.
Marine mammals, meanwhile, have plunged by 80 per cent over the past century, the report said.
Professor Ron Milo, Weinzmann Institute of Science in Israel and lead author, said “It is definitely striking, our disproportionate place on Earth.”
“When I do a puzzle with my daughters, there is usually an elephant next to a giraffe next to a rhino. But if I was trying to give them a more realistic sense of the world, it would be a cow next to a cow next to a cow and then a chicken.”
This staggering imbalance between domestic and wild animals is being driven by industrial farming, extraction of resources, and the expansion of human civilizations, all of which destroy ecosystems, according to the report.
It said other studies have also documented the decline of animals and plants. For instance, scientists recently argued that the Earth is experiencing its sixth mass wave of extinction, with billions of local animal populations endangered around the world.
This decline is by no means slowing down. A study published last week found that if temperatures at the end of the century are 3.2 degrees Celsius higher than pre-industrial levels, species across the animal kingdom could lose up to half of their geographical ranges.
The study spearheaded by Prof Milo, however, is the first taxonomic breakdown of the mass of all organisms on Earth, according to the authors, who noted that further research and advances in technology need to be developed to refine the data.
“I would hope this gives people a perspective on the very dominant role that humanity now plays on Earth,” he said.