a web page by Don Roberson |
MOTMOTS Momotidae |
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The name "motmot" is an original Mexican name for this group of birds, as quoted in a 1651 travel journal, but became garbled by an early German author to "momot," and hence the Latin name of the original genus and family. Motmots sit quietly on a shaded branches, swinging their tail side-to-side rather like a metronome — but I have no idea whether that timing device accounted for the original name. |
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 I
often see parallels in the evolution of birds between the New and Old
worlds — antbirds recall babblers, furnarids recall bulbuls, etc — and
for me, motmots recall bee-eaters. They are not elegant aerialists like
many bee-eaters, so rather I should say that motmots recall the Nyctornis
bee-eaters of southeast Asia: quite, unobtrusive forest birds who breed
by laying eggs in a tunnel that they dig in muddy, earthen banks. These
burrows can be quite deep – 3-5m long (9-16 ft.) for larger species –
and can take weeks to complete. During these weeks of work, the bill
can be quite muddy, even if the motmot comes to a feeder. This Blue-crowned Motmot (right), at a feeder in Costa Rica, must have been engaged in such work. |
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| It has long been said that the racquet-shaped tips of the long central tail feathers are created by the birds themselves, through dedicated preening, but apparently the truth is more prosaic. Juvenal motmots and freshly-molted tails of adults do not have racquets, but the basal feathers are attached only loosely and simply fall out through ordinary wear-and-tear. Preening can be part of that wear, but the birds are not 'trying' to create the distinctive shape (below left; same Broad-billed Motmot as at top of page). Although the pendulum-like movement of the tail has long been noted, no one seems to know the precise purpose of the racquets (Snow 2001). | |||
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Three motmots have 'normal' central rectrices without weaker spots, and these do not form racquets. Blue-throated Motmot (above center) is an elusive motmot in the montane forests of northern Central America, and is much more often heard than seen. It prefers the canopy of pine and humid cloud forests. Tody Motmot Hylomanes momotula is also a Central American species that can be very hard to observe as it sits in the undergrowth, but in drier, lower elevation woods than Blue-throated. The final non-racquet-tailed species is Rufous-capped Motmot Baryphtenengus ruficapillus of southeastern Brazil. Most motmots are birds of rainforests, where their hooting calls are part of the aural backdrop, but Rufous-crowned Motmot (above right) is well-adapted to semi-arid woodlands from western Mexico to Guatemala. Motmots sally out from their perches to eat larger insects, but they also consume a variety of invertebrates, frogs, snakes, lizards, and fledgling or sick small birds. Some species also take fruit seasonally. |
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Photos: The Broad-billed Motmot Electron platyrhynchum, shown in several photos, was at La Selva, Costa Rica, on 17 Dec 2007. The Blue-crowned Motmot Momotus momota was at Rio Tigre, Osa Peninsula, Costa Rica, on 26 Dec 2007. The Blue-throated Motmot Aspatha gularis was at El Triunfo, Chiapas, Mexico, on 23 Mar 2002. The Russet-crowned Motmot Momotus mexicanus was at Singayta, near San Blas, Nayarit, Mexico, on 28 Feb 1987. All photos © 2008 Don Roberson; all rights reserved. Bibliographic note: There is no "family book" per se but a fine introduction, with some impressive photos, is in Snow (2001). Literature cited:
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Motmots
are a small family of sit-and-wait arboreal predators in the New World
tropics. Nearly all have the same basic shape: large head, strong bill,
long body, and 7 of 10 species have a long tail with racquets at the
end of the central rectrices. Broad-billed Motmot
(left) is a example of the 'standard' motmot; it has a wide range in
the Neotropics from tropical Mexico to northern Argentina. Its bill,
however, is broader than most other motmots (below).
