Turquoise-browed Motmot Eumomota superciliosa Scientific name definitions

The Turquoise-browed Motmot is surely one of the most flamboyantly plumaged of a remarkable family, and it is sufficiently distinctive from other motmots to be afforded its own genus. Given its relatively small range, in the Yucatán Peninsula of eastern Mexico and northernmost Guatemala, and on the Pacific slope of Middle America, from southern Mexico south to northwest Costa Rica, it might seem remarkable that as many as seven subspecies are generally recognized. Virtually all of them have largely olive-green underparts with a cinnamon or rufous belly, and a darker reddish patch on the mantle, but the most eye-catching features are the turquoise flash in the flight feathers, the similarly colored eyebrow contrasting with the black mask, and the long graduated bright blue tail, which has the central feathers twice as long as the rest. Although they are reduced to mere shafts over more than half their length, they are ‘capped’ by black-tipped turquoise rackets. The dark bill is relatively long and slightly decurved.

33–38 cm; 44–74 g, means 67·6 g (male) and 66 g (female) (1 Murphy, T.G. (2008). Lack of assortative mating for tail, body size, or condition in the elaborate monomorphic Turquoise-browed Motmot (Eumomota superciliosa). Auk. 125(1): 11-19. Close ). Tail most extremely graduated of family, central rectrices about twice as long as next pair, with bare shafts very long (c. 75 mm), flag-like racquet tip nearly twice as wide as basal part of vane, the two flanges decurved, dropping away from shaft on each side; bill narrow, cutting edges of both mandibles finely serrated along most of length. Racqueted shape of tail attained when weakly attached barbs deliberately shed, with barbs along wire weak due to combination of reduced structural attachment and lack of structurally enhancing melanin in proximal rami (2 Murphy, T.G. (2007). Lack of melanized keratin and barbs that fall off: how the racketed tail of the turquoise-browed motmot Eumomota superciliosa is formed. Journal of Avian Biology. 38(2): 139
-143. Close ); unlike many avian species with “pin” tails, E. superciliosa has the distal portion of the rachis reinforced (3 Tubaro, P.L., Mahler, B. and Lijtmaer, D.A. (2005). Patterns of rectrix rachis modification in pintails and the evolution of sexually selected traits. Biological Journal of the Linnean Society. 86(4): 477–485. Close ). Both sexes in nominate race conspicuous pale, slightly iridescent, turquoise-blue eyebrow, black facial mask with turquoise line below; mainly green above, with chestnut-rufous patch on mantle; flight-feathers turquoise-blue, black-tipped; tail-racquets sharply divided into blue basal half, black distal half; throat and breast olive-green with shaggy black medial stripe edged with turquoise, belly cinnamon; bill black; legs and feet grey. Male larger than female in most body-size characters, including those of the tail (1 Murphy, T.G. (2008). Lack of assortative mating for tail, body size, or condition in the elaborate monomorphic Turquoise-browed Motmot (Eumomota superciliosa). Auk. 125(1): 11-19. Close ), with the latter probably functioning as a sexual signal (4 Murphy, T.G. (2010). Tail-racket removal increases hematocrit in male Turquoise-browed Motmots (Eumomota superciliosa). Journal of Ornithology. 151(1): 241-245. Close ). Furthermore, recent detailed research has revealed that tail colour in both sexes has similar spectral shape, with significant, albeit moderate, dichromatism, males being brighter than females and having marginally greater blue-green saturation, while length of feather grown per day is positively related to overall feather brightness in males, suggesting that tail colour potentially imparts information about individual quality during mate choice (5 Murphy, T.G. and Pham, T.T. (2012). Condition and brightness of structural blue-green: motmot tail-racket brightness is related to speed of feather growth in males, but not in females. Biological Journal of the Linnean Society. 106(3): 673-681. Close ). Distinguished from other momotids by exceptionally long bare tail shafts, blue eyebrow, pattern of throat and breast. Juvenile duller, little or no rufous on back, little of black-and-turquoise stripe below. Races vary mainly in darkness of plumage: bipartita darker, greenish-olive breast and cinnamon-rufous flanks and belly sharply demarcated; sylvestris like previous but generally darker; euroaustris darker turquoise-blue eyebrow, darker wings and tail more purplish-blue; vanrossemi like nominate but brighter green, tawny suffusion reduced; apiaster with green paler, less tawny suffusion; <em>australis</em> distinctive, being small and pale.

Editor's Note: This article requires further editing work to merge existing content into the appropriate Subspecies sections. Please bear with us while this update takes place.

Editor's Note: Additional distribution information for this taxon can be found in the 'Subspecies' article above. In the future we will develop a range-wide distribution article.

Deciduous woodland and woodland edge, evergreen gallery forest, low scrubby thickets, and semi-open areas with scattered trees; also locally plantations and gardens; to 1400 m.

Returns to Yucatán breeding colonies in late Feb or Mar, a few weeks before start of nesting; extent of movement unknown, probably not great and speculated to only move as far as moist forests of C Yucatán (1 Murphy, T.G. (2008). Lack of assortative mating for tail, body size, or condition in the elaborate monomorphic Turquoise-browed Motmot (Eumomota superciliosa). Auk. 125(1): 11-19. Close ). Some seasonal movement probable also in Costa Rica , where more arid habitats occupied mainly in wet season.

Insects , spiders, millipedes, small molluscs, earthworms, and small lizards and snakes; also fruit. Coleoptera, Orthoptera and Hymenoptera are especially important dietary constituents, whereas reptiles constitute just 0·9% by volume (6 Remsen, J.V., Hyde, M.A. and Chapman, A. (1993). The diets of Neotropical trogons, motmots, barbets and toucans. Condor. 95(1): 178-192. Close ). Fruit also in small quantities, e.g. 3·4% by volume of stomach contents in Yucatán; species recorded taken include Stemmadenia, Ficus, Bursera, Ehretia and Guaiacum. Observed feeding on flying insects around artificial streetlights almost one hour after sunset, in El Salvador (7 Thurber, W.A. and Komar, O. (2002). Turquoise-browed Motmot (Eumomota superciliosa) feeds by artificial light. Wilson Bull.. 114(4): 525-526. Close ). Animal food seized in sudden dart to vegetation or ground, or in aerial sally; butterflies, bees, dragonflies and smaller insects also taken in flight. Larger prey is struck up to eight times against perch prior to consumption (7 Thurber, W.A. and Komar, O. (2002). Turquoise-browed Motmot (Eumomota superciliosa) feeds by artificial light. Wilson Bull.. 114(4): 525-526. Close ).

Like other motmots, gives a hollow, nasal, ringing "wohh" or "owhh", given at rate of one per 3·5–4·5 sec and higher and less resonant than Electron motmots, with varied, also hollow, but slightly hoarse, clucking calls, including a rhythmic "k'wok k'wok..." and a longer "k'wok t'k'wok t'k'wok t'k'wok..." (the latter perhaps in duet), have also been recorded (8 Howell, S. N. G., and S. Webb (1995). A Guide to the Birds of Mexico and Northern Central America. Oxford University Press, New York, NY, USA. Close ).

Lays second week May to mid-Jul (peak first half Jun) in Mexico; Apr–May in Guatemala and Honduras; late Mar to mid-Apr in NW Costa Rica (9 Barrantes, G. (1998). Reproductive activity of birds in a mangrove swamp in northwest Costa Rica. Rev. Biol. Tropical. 46(4): 1163–1166. Close ); may re-lay after early nest failure. Contrary to some predictions, no evidence of assortative mating for tail components, body size or phenotypic condition, in Yucatán population, although same study uncovered some evidence that birds >2 years old select partners of a similar age and phenotypic condition (1 Murphy, T.G. (2008). Lack of assortative mating for tail, body size, or condition in the elaborate monomorphic Turquoise-browed Motmot (Eumomota superciliosa). Auk. 125(1): 11-19. Close ). Pair-bond maintained over successive years, and individuals faithful to nest-sites; either solitary or colonial, depending on availability of suitable nest-sites, some colonies number over 100 pairs, but in the Yucatán colonies range in size from 2–60 pairs, with 10–20 pairs most common (1 Murphy, T.G. (2008). Lack of assortative mating for tail, body size, or condition in the elaborate monomorphic Turquoise-browed Motmot (Eumomota superciliosa). Auk. 125(1): 11-19. Close ). Nest typically in burrow excavated in earth bank or low cliff; burrow often curved, total length very variable, 40–244 cm (mean 130 cm) (1 Murphy, T.G. (2008). Lack of assortative mating for tail, body size, or condition in the elaborate monomorphic Turquoise-browed Motmot (Eumomota superciliosa). Auk. 125(1): 11-19. Close ), ending in enlarged nest-chamber c. 20–23 cm wide and c. 10 cm high; in Yucatán, Mexico, also uses beam-socket and ventilation holes of archaeological ruins, sinkholes and freshwater wells (1 Murphy, T.G. (2008). Lack of assortative mating for tail, body size, or condition in the elaborate monomorphic Turquoise-browed Motmot (Eumomota superciliosa). Auk. 125(1): 11-19. Close ). Clutch 2–6 eggs, most often four, laid at intervals of c. 48 hours; incubation 18–20 days; fledging 24–31 days. In Yucatán archaeological sites, 36% of all nesting attempts failed owing to predation, probably by rat-snake (Elaphe phaescens).

Not globally threatened. One of the most abundant motmots, common to fairly common throughout range. Well adapted to secondary vegetation and semi-open country in areas much altered by man; also able to exploit nesting opportunities created by man, where breeding adults become conditioned to presence of human visitors. The national bird of El Salvador (10 Komar, O. (1998) Avian diversity in El Salvador. Wilson Bulletin 110(4):511–533. Close ).