Feeding ecology and diet

Motmots are omnivorous, taking invertebrates, small animals, and fruits. Invertebrates include beetles, butterflies (Morphos) and caterpillars, dragonflies, mantises, cicadas, spiders, centipedes, millipedes, scorpions, snails, earthworms, and crabs. Small animals include anole and gecko lizards, small snakes, frogs, small fish, an occasional nestling bird, and, in one recorded case, a blue-crowned motmot took a mouse. Fruits include those of palms, heliconia (Heliconia), nutmegs (Compsoneura, Virola), incense (Bursera), figs (Ficus), and other fruits. Frugivory (fruit consumption) seems to increase with size. For example, Remsen and colleagues found broad-billed motmots to be largely insectivorous, but rufous and blue-crowned motmots were more frugivorous. There are no records of the smallest species, the tody motmot, taking fruit.

Different motmot species obtain their prey in different ways, although patterns overlap. Smaller species appear to sally more as sit-and-wait strategists; larger species often perform long, broadcasting flights while continuously searching for prey. Smaller species also seem to catch more prey on the wing than larger species. Prey too large to swallow whole are often seized with the bill and clubbed against a perch. Pellets may be regurgitated. Several motmot species are "ant-following" birds that take insects turned up by long trains of army ants.

Smaller seeds of consumed fruits are passed through and dispersed; larger seeds are regurgitated on the spot. Species such as rufous motmots are important dispersers of the nutmeg Virola surinamensis, accounting for approximately 17% of dispersed fruits. Seed dispersal helps regenerate tropical forests.

Motmots nest in an underground chamber dug by both sexes. They take turns loosening the soil and kicking dirt out toward the opening. The chamber may be up to 16 ft (5 m) long in larger species. Eggs remain on bare soil, but hard insect parts regurgitated by incubating parents may be added underneath.

Eggs are rounded, shiny, and white. The clutch typically ranges from three to five eggs. In middle America, eggs are typically laid every other day between March and June; April and May are peak laying months. Typically a single clutch is laid each season, but if a clutch is lost replacement clutches are laid after 10-21 days. Both sexes incubate eggs during long shifts, perhaps changing duties once in 24 hours. Incubation is 17-22 days, depending on the species.

Chicks hatch blind, featherless, and dependent on parents. Skutch provides information on development from studying broad-billed motmots: partly feathered at 11 days, eyes begin opening at 12 days, soft calls at 13 days, taking food at burrow entrance at 15 days, and leave nest at 25 days. Young blue-throated motmots have soft down that appears soon after hatching. Both sexes care for the brood and feed the chicks lepidopterans and other insects, vertebrate innards, and protein-rich fruits. Young generally leave the nest at 24-32 days, though one record has a blue-crowned mot-mot leaving the nest at 38 days.

A blue-crowned motmot (Momotus momota) carrying a rain frog to its nestlings. (Photo by M.P.L. Fogden. Bruce Coleman Inc. Reproduced by permission.)

Was this article helpful?

0 0

Post a comment