Six times as many birds live on Earth, according to a new study | the animals

Scientists from the University of New South Wales (Australia) used eBird, one of the largest citizen science projects in the field of biodiversity. They have estimated the number of 9,700 species of birds by drawing on hundreds of millions of observations on eBird.

The researchers combined the data with professional scientific observations to develop an algorithm that would estimate the population numbers of nearly all species. They find that there are relatively few common bird species, but a large number of rare species.

There are two reasons for this scarcity. Some species live in very specific habitats, such as a specific island or on top of a mountain. But in other cases it is also rare, due to human causes.

Four types are very common. Scientists call them the “billion dollar club.” Each of these species is estimated to number more than a billion individual birds. These species are house sparrows, starlings, ringed gulls, and barn swallows.

The aim of the study is to be able to find out if some species have declined over time in terms of population and where we should focus on species conservation.

There are still some uncertainties in the numbers, said Will Cornwell, one of the study’s authors, and the researchers plan to improve the model as professional research is conducted into more species. He would like to emphasize that the research shows the importance of citizen science.