Incubation times vary from species to species and are correlated with body size, lasting 28 days in smaller species and up to 35 days in larger species. Around 2–4 eggs are laid, and mostly incubated by the female. Nests are generally not built (except by the caracaras), but are co opted from other birds, for example pygmy falcons nest in the nests of weavers, or on the ledges on cliffs. They are monogamous, although some caracaras may also employ alloparenting strategies, where younger birds help adults (usually their parents) in raising the next brood of chicks. The falcons and caracaras are generally solitary breeders, although around 10% of species are colonial, for example the red-footed falcon. The red-footed falcon is unusual in being a colonial breeding falcon The Amur falcon has one of the longest migrations, moving from East Asia to southern Africa. Some species, mostly in the genus Falco, are fully migratory, with some species summering in Eurasia and wintering entirely in Africa, other species may be partly migratory. Most habitat types are occupied, from tundra to rainforest and deserts, although they are generally more birds of open country and even forest species tend to prefer broken forest and forest edges. Other species have more restricted distributions, particularly island endemics like the Mauritius kestrel. Some species have exceptionally wide ranges, particularly the cosmopolitan peregrine falcon, which ranges from Greenland to Fiji and has the widest natural breeding distribution of any bird. The family has a cosmopolitan distribution across the world, absent only from the densest forest of central Africa, some remote oceanic islands, the high Arctic and Antarctica.
There is little difference in the plumage of males and females, although a few species have some sexual dimorphism in boldness of plumage. The plumage is usually composed of browns, whites, chestnut, black and grey, often with barring of patterning. They have strongly hooked bills, sharply curved talons and excellent eyesight. Falcons and caracaras are small to medium-sized birds of prey, ranging in size from the black-thighed falconet, which can weigh as little as 35 grams (1.2 oz), to the gyrfalcon, which can weigh as much as 1,735 grams (61.2 oz).