The following information is summarized from Skutch (1962):
Nest: In a burrow. The site for the burrow may be "almost any vertical or steeply inclined surface of bare earth." This includes steep slopes, banks, gully walls, clay adhering to fallen tree roots, and termitaries. The burrows are approximately between 30-40 cm in length and roughly 4.4 cm in diameter. Nests may be reused in successive years.
Eggs: A clutch consists of 2-4 eggs that are white spotted with cinnamon, nearly rounded, and that measure approximately 22-23 mm x 19-20 mm. In Costa Rica, eggs are laid March-June. The breeding season in northern Colombia may be primarily January-April, but a female incubating three eggs also was reported from October (Hilty and Brown 1986). In northern Venezuela, breeds August-September (Hilty 2003).
Incubation: The female incubates during the night and alternates with the male during the day. The female will leave early in the morning, often before the male's arrival, and start the nocturnal session in the late afternoon. Incubation may begin before the last egg has been laid and will last for 19-23 days.
Nestlings: The young hatch with long, white natal down. The lower part of the bill extends beyond the upper. The fours toes point forward (adults have the outer and inner toes behind). The heel is protected by a pad. The young can support their weight shortly after hatching. Pin feathers appear after six days, and plumage coverage occurs after eighteen days. For information about calls, see Vocalizations.
Feeding the young: Parents provide insects, especially butterflies but also dragonflies and other flying insects. The prey is beaten in accordance to the size and toughness of the insect (more knocks if the prey us larger and tougher). Food is delivered one item at a time. As the nestlings age, they meet the parent close to the burrow entrance. At this point, the adult will only remain near the entrance for a few seconds, departing to its perch with the food if the young are not prompt. The food will likely be re-offered after an interval. The male provides more food and is more consistent than the female. Nestlings are fed at a rate of about 2-4 times per hour.
Fledging: The time the young leave the burrow ranges around 20-26 days, with later broods leaving after more days than early broods. The latest month to fledge is July. Skutch (1968) found the nestling period in Venezuela to be only 18-19 days.
Other information: Nests are not kept sanitary. Regurgitated food fragments, eggs shells, and nestling droppings accumulate. The nestlings stand, rather than lie down, so plumage is protected from the debris. Gilliard (1959) observed jacamars "violently" attack and drive away Southern Rough-winged Swallows (Stelgidopteryx ruficollis) that flew near the entrance to an active jacamar nest burrow in Venezuela.