The jacamars are small to medium sized perching birds ranging between 14-34 cm in length and weighing between 17-75 g. They are glossy elegant birds with long bills and tails. In appearance and behaviour they show resemblances to the Old World bee-eaters, as most ariel insectivores tend to have short wide bills as opposed to long thin ones. The legs are short and weak, and the feet are zygodactyl. Their plumage is often bright and highly iridescent, although it is quite dull in a few species. There are minor differences in plumage based on sex, males often having a white patch on the breast.
Jacamars are insectivores, taking a variety of insect prey (many specialize on butterflies and moths) by hawking in the air. Birds sit in favoured perches and sally towards the prey when it is close enough. Only the Great Jacamar varies from the rest of the family, taking prey by gleaning and occasionally taking small lizards and spiders.
The breeding systems of jacamars have not been studied in depth. They are thought to generally be monogamous, although a few species are thought to sometimes engage in cooperative breeding with several adults sharing duties. The family nests in holes either in the soil or in arboreal termite mounds. Ground nesting species usually nest in the banks of rivers (or more recently, roads), although if these are not available they will nest in the soil held by the roots of fallen trees. Bank-nesting jacamars can sometimes be loosely colonial. Clutch sizes are between 1-4 eggs, with 2-4 being more common. Both parents participate in incubation. Little is known about the incubation times of most species, although it lasts for between 19-26 days in the Rufous-tailed Jacamar. Chicks are born with down feathers, unique among the piciformes. Their prey includes Morpho Butterfly.