Which bird of prey had only four known wild individuals in 1974?

The bird of prey with only four known wild individuals in 1974 was the Mauritius kestrel.

The Mauritius kestrel (Falco punctatus) is a small falcon endemic to Mauritius. By 1974, habitat loss, pesticide exposure, introduced predators, and other human pressures had reduced its wild population to an all-time low of four birds. It was then regarded as the rarest bird in the world.

Conservationists began organized recovery efforts in the 1970s, involving the Mauritius Forestry Department and international partners. Early captive-breeding attempts were difficult: a 1973 effort failed after an incubator breakdown killed a hatchling, and later attempts initially struggled with infertile eggs.

The species eventually became a landmark conservation success through captive breeding, habitat protection, and the release of young birds. It is not the same as the peregrine falcon, red kite, or lanner falcon. The especially revealing clue is the combination of a Mauritius-only range and the precisely documented four-bird low point.