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How many birds are there in the world?

How many birds are there in the world?
about 50 billion wild birds
About six wild birds per person. Farmed chickens, at roughly 26 billion alive at any moment, amount to half again the population of every wild bird species combined in terms of biomass.

A 2021 analysis estimated roughly 50 billion individual wild birds across about 9,700 species. The distribution is startlingly uneven: four species — house sparrow, European starling, ring-billed gull and barn swallow — each number over a billion, while about 1,180 species have fewer than 5,000 individuals each. Most bird species are rare and a handful are astronomically common. The confidence interval on the global total is wide, roughly 40 to 60 billion.

How the figure is arrived at

Citizen-science sightings from eBird — over a billion records — were used to fit a relationship between how often a species is reported and how abundant it actually is, calibrated against the species where proper systematic surveys exist. The fitted relationship then predicts abundance for the species that have never been surveyed properly.

How confident it is

Low estimate
40,000,000,000
High estimate
60,000,000,000
Spread
1.5× between the bounds

Other living things and the natural world counts

Common questions

How many birds are there in the world?
about 50 billion wild birds
How is that estimated?
Citizen-science sightings from eBird — over a billion records — were used to fit a relationship between how often a species is reported and how abundant it actually is, calibrated against the species where proper systematic surveys exist. The fitted relationship then predicts abundance for the species that have never been surveyed properly.

Related pages

Sources

  1. Typical range compiled from manufacturer specifications — At One Place

How these figures are compiled and checked