
In the case of the California condor, the height of the population seems to be during the last North American ice age, where megafauna roamed the land. Firstly, it’s important to know that a larger bird can eat larger carcasses.

There isn’t a cut and dry answer to why condors are so much larger than the average vulture (black and turkey vultures, for example), but some evolutionary evidence can point us in the right direction. On the coast, they are known to eat beached fish and sealife. The potential carrion carcasses include things like llamas, alpacas, rheas, and guanacos, but most condors that live inland have adapted to feed almost entirely on cattle. The Andean condor lives along the Andes mountain range (hence the name) and has access to large swaths of territory where large animals live. Why are condors so big? Condors are the largest birds within the New World order of vultures. Altogether, they are the largest wingspan of any North American bird, but a few species of swans, pelicans, and albatrosses are heavier and/or taller. The wingspan of the California condor is around 10 ft, but there have been claims (without evidence) that they can grow to 11 ft. Males are slightly larger (like the Andean condor), making them another exception to the sexual dimorphism present with most raptors. The California condor, slightly smaller than the Andean condor, averages out at 18-20 lbs, but can grow larger, with some individuals recorded at 30 lbs. When standing, they average almost 4 ft tall. Additionally, they have the largest surface area of any bird’s wingspan in the world. 10 inches, giving them one of the largest in the entire world, only exceeded by a few pelican and albatross species. They are the heaviest average flying animal or bird in the world (although bustards occasionally weigh more). The heaviest Andean condor was recorded at 33 lbs. Female Andean condors weigh around 25 lbs, while males weigh up to 28 lbs (this difference is usually reversed in birds of prey, making it notable).

The Andean condor is the larger of the two condors by a decent margin. The Best Nest Boxes Birds Will Actually Use for 2022 Andean condor size
