Sizeable populations of smaller birds, including warblers, sparrows, and house finches, are also common. Bird species of cockatoos, kookaburras, quails, finches and hawks also flourished. The seeds are eaten by several species of grassland birds, particularly buntings and finches. The weavers are small passerine birds related to the finches. Male saffron finches and canaries have been used in fights on occasion. Weavers are a group of small passerine birds related to the finches. They form hybrids with some other finches (for example canaries) giving rise to intermediate species. All species are brood parasites which lay their eggs in the nests of estrildid finches. All are brood parasites which lay their eggs in the nests of estrildid finches. All are brood parasites, which lay their eggs in the nests of estrildid finches. The birds were sold illegally in New York City as "Hollywood Finches", a marketing artifice. He is well known for breeding Gouldian finches. They belong to the tanager family and are not closely related to the true finches. Another example is the beak size in a population of finches. House finches forage on the ground or in vegetation normally.