Finches are common pet birds because several of their characteristics allow them to do well caged. They are usually quite small, especially as pets, and have a remarkable array of colors and patterns to choose from. They are overall quiet, only calling for specific reasons. Their mating characteristics make it possible for them to be home bred, so you can continue to enjoy them as a group, potentially even in the same cage.
Finches are usually small to medium in size, ranging from three to 10 inches in length. They have a compact body and their head has a slight peak. Their tails are slightly long, and have 12 feathers. In terms of birds, their neck is very short, and their beak is cone-shaped. This cone shape is most noticeable when looking at the finch head on. Finches can be found in a wide variety of colors, ranging from dull grays and brown to extremely bright purple and yellow. They also have a variety of patterns within these colorations that help distinguish each species. Chicks have distinct markings inside their mouths that can be seen when their mouths are open begging to be fed. These may have some behavioral relevance, as each species of finch chick has different, high-contrast markings. Finches have monocular vision, meaning their eyes are set far apart on the sides of their heads, in order to see all around them to look out for predators.
Finches are good at flying, running, and hopping. Many species migrate over long distances, requiring a strong ability to fly. They are constantly flying or hopping around in search of food, and are not the type of pet that would sit on your hand calmly. Male finches choose a large territory to defend near a good food source. They have very specific calls that help them defend that territory from predators and other male finches. Since finches are prey items in the wild, they stay on guard most of the time, even as pets. They see larger animals and humans as a threat, and have a series of warning calls that they make when they see predators. These calls vary widely from species to species. The patterned mouth markings that finch chicks exhibit may be related to calling the right parent over to the nest. The chicks often do a head bobbing and a little dance along with opening their mouth wide while waiting for the parent to return to the nest. They have distinct calls for this as well.
Finches are usually monogamous after they find their mate. The mated pair will continue to mate with each other for the rest of the breeding season. Some of the more social species of finch form small groups that stay together. Females make small, cup-shaped nests, and are the main parent to sit on the eggs until they hatch, although the male does help with this. Finches can lay up to six eggs at a time. Parents are usually very devoted to incubating their eggs, and will remain on the nest no matter what dangers may come by. When the chicks reach an acceptable age to leave the nest, the parents push them out aggressively, which helps in weaning. Then, the parents will breed again for a new set of eggs. As juvenile finches reach maturity, they become domineering in their mating behavior. The males spend a lot of time calling to defend their territory against other males in the area.