Estrildid finches, or Estrildidae, are a group of small, tropical, seed-eating birds that includes munias, mannikins, firefinches, parrotfinches, and waxbills. Found primarily in the Old World tropics and Australasia, these finches are not closely related to the true finches of other families. These birds exhibit a variety of plumage colors and patterns but generally share similar structures and behaviors. They tend to be sociable and many species live in colonies. These birds use their short, thick, and pointed bills to feed on seeds and often build large, dome-shaped nests where they lay five to ten white eggs. Some species have also evolved to live in cooler climates, such as in southern Australia and New Guinea's highlands.
Estrildids are sensitive to cold and require warm habitats; exceptions include species like the eastern alpine mannikin and the mountain firetail which can tolerate cooler temperatures. They range in size from the tiny 8.3 cm (3.3 in) Shelley's oliveback to the larger 17 cm (6.7 in) Java sparrow.
In terms of taxonomy, the Estrildidae family was first introduced by Charles Lucien Bonaparte in 1850. Modern studies conducted by Urban Olsson and Per Alström have proposed the division of the family into six clades or subfamilies, based on their genetic research. This family is also closely related to the Viduidae family, which includes indigobirds and whydahs, and it is believed that the two families diverged around 15.5 million years ago. The family consists of a diverse range of 139 species across 41 genera, showcasing a variety of adaptations and ecological niches within the passerine bird community.