Islamabad - Talk about getting your ducks in a row.There are roughly 50 billion individual birds in the world, a new big data study by UNSW Sydney suggests — about six birds for every human on the planet.The study — which bases its findings on citizen science observations and detailed algorithms — estimates how many birds belong to 9700 different bird species, including flightless birds like emus and penguins. It found many iconic Australian birds are numbered in the millions, like the Rainbow Lorikeet (19 million), Sulphur-crested Cockatoo (10 million) and Laughing Kookaburra (3.4 million). But other natives, like the rare Black-breasted Buttonquail, only have around 100 members left. The findings are being published this week in the Proceedings of the National Academy of Sciences. “Humans have spent a great deal of effort counting the members of our own species — all 7.8 billion of us,” says Associate Professor Will Cornwell, an ecologist at UNSW Science and co-senior author of the study. “This is the first comprehensive effort to count a suite of other species.”

The research team reached their figures by pooling together almost a billion bird sightings, an online database of bird observations from citizen scientists. Using this data — and detailed case studies where available — they then developed an algorithm to estimate the actual global population of each bird species.