What is the most numerous wild bird species in the world?

The red-billed quelea is the most numerous wild bird species in the world, with post-breeding numbers sometimes estimated at about 1.5 billion.

This small weaver is native to sub-Saharan Africa and moves nomadically in response to seasonal rains and grass-seed supplies. It gathers in immense breeding colonies and can form flocks containing millions of birds, creating the famous appearance of a rolling cloud in the sky.

Queleas mainly eat seeds from annual grasses, but they also feed in cultivated fields and can cause serious losses to cereal crops. This agricultural impact has earned them the nickname “Africa’s feathered locust.” Large-scale control efforts, including avicides and attempts to destroy roosts, have generally failed to suppress the species for long because its food and range are so widespread.

The answer refers to wild, or undomesticated, birds. It does not mean the most common bird seen around towns or gardens, where pigeons, starlings, or sparrows may be more familiar. Despite its huge population, the red-billed quelea is currently classified as Least Concern.