Plumages, Molts, and Structure

The Hispaniolan Trogon has 10 functional primaries (numbered distally, from innermost p1 to outermost p10, the p10 short and thin), 9 secondaries (numbered proximally, from outermost s1 to innermost s6 and including three tertials, numbered t1–t3 distally), and 12 rectrices (numbered distally on each side of the tail, from innermost r1 to outermost r6); the tail in graduated, with the tips of r6 falling well short of the tail tip. The secondaries and inner primaries (p1–p2) are rather short and the outer six primaries (p5–p10) are strongly curved, leading to a unique wing shape characteristic of trogons. Body feathering is notably soft and "dry-textured," and many trogon species have spine-like shafts to uppertail coverts (2 Collar, N. J. (2001). Family Trogonidae (Trogons). in Handbook of the Birds of the World, vol. 6: Mousebirds to Hornbills ( J. del Hoyo, A. Elliott , and J. Sargatal , Editors.). Lynx Edicions, Barcelona, Spain. pp 80–129. Close ). No geographic variation in appearance has been described for Hispaniolan Trogon (see Systematics). The following is based primarily on detailed plumage descriptions of Ridgway (3 Ridgway, R. (1911). The birds of North and Middle America: A descriptive catalogue of the higher groups, genera, species, and subspecies of birds known to occur in North America, from the Arctic Lands to the Isthmus of Panama, the West Indies and other Islands of the Caribbean Sea, and the Galapagos Archipelago. Part V. Bulletin of the United States National Museum 50. Close ), Wetmore and Swales (1 Wetmore, A., and B. H. Swales (1931). The birds of Haiti and the Dominican Republic. United States National Museum Bulletin 155. Smithsonian Institution, Washington, DC, USA. Close ), and Collar (2 Collar, N. J. (2001). Family Trogonidae (Trogons). in Handbook of the Birds of the World, vol. 6: Mousebirds to Hornbills ( J. del Hoyo, A. Elliott , and J. Sargatal , Editors.). Lynx Edicions, Barcelona, Spain. pp 80–129. Close ), along with examination of Macaulay Library images; see Pyle (4 Pyle, P. (1995). Incomplete flight feather molt and age in certain North American non-passerines. North American Bird Bander 20:15–26. Close , 5 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, California, USA. Close ) and Johnson and Wolfe (6 Johnson, E. I., and J. D. Wolfe (2018). Molt in Neotropical Birds: Life History and Aging Criteria. Studies in Avian Biology 51. CRC Press, Boca Raton, FL, USA. Close ) for age and sex criteria in similar species of Trogonidae. See Molts for molt and plumage terminology. Sexes may differ slightly in Juvenile Plumage (see below) and differ more markedly in all subsequent plumages. Definitive appearance is attained at the Second Basic Plumage. Timing of plumages (fresh versus worn) is based on that of molt, which may typically follow breeding in May–June (see Breeding: Phenology) but study is needed on the seasonality of both breeding and molt in this species.

Natal Down

Undescribed.

Juvenile (First Basic) Plumage

Juvenile Plumage is undescribed in Hispaniolan Trogon but in most trogons it is duller and duskier than later plumages. As in all trogons, juvenile flight feathers are narrower, more rounded or tapered, and duller, the rectrices not truncated and flared at the tips as in Definitive Basic Plumage. Juvenile central rectrices from above show an indistinct and rounded dusky band at the tip, and the middle rectrices (r3–r5) from below show longer and more ovate white spots with a transverse border and a dusky bar which is narrower than in basic rectrices (see images below). Iris color also appears to be brownish to brownish-red in Juveniles (see Bare Parts).

Among Macaulay Library images there appear to be few birds in predefinitive plumages and only one candidate in fresh juvenile plumage (see left-hand image below), showing fresh juvenile rectrices. The patterns to the wing coverts, tertials, and secondaries are unlike those of basic feathers in either sex; the dull barring may be typical of juvenile feathers in males. The moderately distinct barring to the outer webs of the primaries may also be typical of juvenile feathers in males, as opposed to absent or very indistinct in juvenile primaries of females. However, more study is needed on sexing of juveniles and formative birds in this species.

Formative Plumage

As in other trogons, Formative Plumage appears to be identified by the retention of juvenile rectrices and remiges. Juvenile rectrices are as described under Juvenile Plumage, above, and are also relatively more worn than basic feathers at the same time of the year. Juvenile alula, primary coverts, and primaries are retained, narrower, more tapered at the tips, and browner than definitive feathers. Remiges do not show molt clines (see below). All secondary coverts appear to be replaced and 1–2 inner tertials may sometimes be replaced, as in other trogons, resulting in a molt limits (see right-hand image below). Iris color also appears to gradually change from reddish brown to brownish red in first-year birds (see Bare Parts).

The pattern to the outer webs of the juvenile primaries may be sex-specific, being less distinct in each sex than basic feathers but allowing females (unbarred) and males (moderately barred) to be distinguished in Juvenile and Formative Plumages. Assuming upperwing secondary coverts and sometimes 1–2 tertials are replaced during the Preformative Molt, as is typical of trogons, they should show patterns of basic feathers allowing confirmation of sex.

Definitive Basic Plumage

Female. Forecrown dark metallic green; hindcrown, nape, lores, sides of head, upper throat, and sometimes portions of the upper back slaty gray; remainder of upperparts and most upperwing lesser coverts dark metallic green, sometimes tinged dark bluish. Central rectrices (r1) with outer web dark metallic blue and inner web bronzy olive, broadly tipped with dark metallic blue; r2 entirely dark metallic blue or greenish blue; r3–r5 similar but with broad white tips and a broad subterminal blue-black band on the outer webs; r6 with white outer web and broad white tip to the inner web; slight barring can be present near the borders of white and dark. Upperwing median and greater coverts dusky tinged metallic green; tertials and secondaries unmarked dusky to grayish; primaries dusky to blackish, the outer webs whitish to white with indistinct or sparse dark barring. Lower throat slate gray, blending to gray on the breast and sides, the lower throat and upper beast tinged with metallic bluish and green; abdomen, ventral region, and undertail coverts contrastingly bright red. Underwing coverts primarily gray as on the breast, the median and greater coverts pale gray to whitish forming a pale bar in flight (cf. ML463886571 , ML615342282 ).

Male. Similar to definitive basic female but the upperwing secondary coverts, primary coverts, and the secondaries boldly barred black and white. The outer web to the basic outer primaries is also brighter white with more distinct and bold barring. The throat feathers are elongated and can be extended in males at least (cf. ML619114422 ), presumably for territoriality or display.

In both sexes, Definitive Basic Plumage is distinguished from Formative Plumage by having uniformly basic wing and tail feathers. The rectrices are broad and squared or flared at the tips; the central rectrix from above shows a broad and square metallic-blue band at the tip and the middle rectrices (r3–r5) from below with broad square white tips and broader bordering metallic-blue bands. Primary coverts, alula, and primaries are blacker, the primaries brighter white and bolder than in juvenile feathers within each sex. Remiges show molt clines, from more worn p1 to blacker and fresher p10, and convergently within the secondaries such that the middle secondaries (centered at s5–s6) are darker than the inner and outer secondaries.

In other species of trogons, secondaries or occasionally rectrices can be retained during prebasic molts, allowing identification of Second Basic Plumage if retained feathers are juvenile or of Third Basic Plumage or older if retained feathers are basic (4 Pyle, P. (1995). Incomplete flight feather molt and age in certain North American non-passerines. North American Bird Bander 20:15–26. Close , 7 Pyle, P. (1997). Identification Guide to North American Birds. Part I. Slate Creek Press, Bolinas, CA, USA. Close , 6 Johnson, E. I., and J. D. Wolfe (2018). Molt in Neotropical Birds: Life History and Aging Criteria. Studies in Avian Biology 51. CRC Press, Boca Raton, FL, USA. Close ). Retained secondaries or other feathers should be looked for in Hispaniolan Trogon.

Molt and plumage terminology follows Humphrey and Parkes (8 Humphrey, P. S., and K. C. Parkes (1959). An approach to the study of molts and plumages. The Auk 76:1–31. Close ) as modified by Howell et al. (9 Howell, S. N. G., C. Corben, P. Pyle, and D. I. Rogers (2003). The first basic problem: A review of molt and plumage homologies. The Condor 105:635–653. Close ). Under this nomenclature, terminology is based on evolution of molts along ancestral lineages of birds from ecdysis (molts) of reptiles (cf. 10 Pyle, P., S. N. G. Howell, D. I. Rogers, and C. Corben (2024). Moult terminology: envisioning an evolutionary approach. Journal of Avian Biology 2024:e03169. Close ), rather than on molts relative to breeding season, location, or time of the year, the latter generally referred to as "life-cycle" molt terminology; see Jenni and Winkler (11 Jenni, L., and R. Winkler (2020). Moult and Ageing of European Passerines. Second edition. Bloomsbury, London, UK. Close ) and Pyle (12 Pyle, P. (2022). Defining moults in migratory birds: A sequence-based approach. Journal of Avian Biology 2022:e02958. Close , 5 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, California, USA. Close ) for more information. Molt in trogons worldwide is not well studied, but all seem to show a similar strategy based on limited studies to date (4 Pyle, P. (1995). Incomplete flight feather molt and age in certain North American non-passerines. North American Bird Bander 20:15–26. Close , 2 Collar, N. J. (2001). Family Trogonidae (Trogons). in Handbook of the Birds of the World, vol. 6: Mousebirds to Hornbills ( J. del Hoyo, A. Elliott , and J. Sargatal , Editors.). Lynx Edicions, Barcelona, Spain. pp 80–129. Close , 6 Johnson, E. I., and J. D. Wolfe (2018). Molt in Neotropical Birds: Life History and Aging Criteria. Studies in Avian Biology 51. CRC Press, Boca Raton, FL, USA. Close , 5 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, California, USA. Close ). The Hispaniolan Trogon appears to follow the molt strategy of other trogons, exhibiting a Complex Basic Strategy (cf. 9 Howell, S. N. G., C. Corben, P. Pyle, and D. I. Rogers (2003). The first basic problem: A review of molt and plumage homologies. The Condor 105:635–653. Close , 13 Jones, A. W. (2010). Book review: Molt in North American birds. Condor 112(4):862–863. Close ), including complete prebasic molts and a partial preformative molt but no prealternate molts. Seasonal timing of molts is not known, but both preformative and prebasic molts likely occur within 2–5 months of fledging and breeding, which may peak in May–July (see Breeding: Phenology). There are few or no images of birds replacing flight feathers among Macaulay Library images, indicating that they are likely retiring during this period; examination of feather wear among these images suggests that molting may occur primarily in July–November but confirmation of this is needed.

Prejuvenile Molt

Presumably complete in the nest or natal territory. No information on timing or rates of juvenile feather development in Hispaniolan Trogon.

Preformative Molt

Partial. Based on Macaulay Library images this molt appears to include most or all body plumage, usually all upperwing secondary coverts, up to 1–3 tertials, and possibly up to two pairs of central rectrices as is found commonly in other trogons. The juvenile alula, primary coverts, primaries, secondaries other than tertials, and outer rectrices appear to be retained in most or all individuals. See images under Formative Plumage.

Definitive Prebasic Molt

Complete. Sequence appears to be the same as other trogons: primaries are replaced distally (p1 to p10), secondaries are replaced bidirectionally from the second tertial and proximally from s1, and rectrices are generally replaced distally (r1 to r6) on each side of tail, with some variation in rectrix sequence possible. The last secondaries replaced appear to be in the center of the tract, among s5–s6.

In other species of trogons, the prebasic molts can occasionally be incomplete, with 1–2 secondaries and less commonly 1–2 rectrices retained (4 Pyle, P. (1995). Incomplete flight feather molt and age in certain North American non-passerines. North American Bird Bander 20:15–26. Close , 7 Pyle, P. (1997). Identification Guide to North American Birds. Part I. Slate Creek Press, Bolinas, CA, USA. Close , 6 Johnson, E. I., and J. D. Wolfe (2018). Molt in Neotropical Birds: Life History and Aging Criteria. Studies in Avian Biology 51. CRC Press, Boca Raton, FL, USA. Close ). During the Second Prebasic Molt, retained juvenile feathers occur most commonly in the center of the secondary tract (among s3–s6) or among the outer rectrices. During later prebasic molts, retained basic feathers may occur here or occasionally elsewhere within these tracts. Study is needed on whether Hispaniolan Trogon can occasionally retain feathers during incomplete prebasic molts.

The following is based on descriptions in the literature (1 Wetmore, A., and B. H. Swales (1931). The birds of Haiti and the Dominican Republic. United States National Museum Bulletin 155. Smithsonian Institution, Washington, DC, USA. Close , 2 Collar, N. J. (2001). Family Trogonidae (Trogons). in Handbook of the Birds of the World, vol. 6: Mousebirds to Hornbills ( J. del Hoyo, A. Elliott , and J. Sargatal , Editors.). Lynx Edicions, Barcelona, Spain. pp 80–129. Close ), along with examination of Macaulay Library images.

Bill

The bill is short and stout with a decurved culmen, and has a slight "tooth" along the cutting edge of the upper mandible as is often found in fruit-eating birds. In both sexes of juveniles and adults the bill is bright yellow tinged orange. It is possible that it becomes more vivid during pre-breeding and breeding periods (perhaps January–June) than during molting and non breeding periods (perhaps August–December). Bill color in nestlings is unknown but is in other trogons it is often dark; the bill tip in juveniles and young first-year birds may have a black tip (see image below) perhaps representing a remnant of receding dark coloration of hatchlings.

Iris

In adults, the iris varies from bright pale orange to bright red (e.g., ML204620811 ). Similar to bill color, iris color may become brighter during pre-breeding and breeding periods. In juveniles it appears to be primarily dull reddish brown, gradually becoming brownish red and dull red over the first year (see images under Plumages).

Tarsi and Toes

Legs in trogons are short and feet are weak. In Hispaniolan Trogon they are usually brownish to brownish gray, with black claws.

Linear Measurements

Total length: 27–30 cm (14 Raffaele, H. A., J. Wiley, O. Garrido, A. Keith, and J. Raffaele (1998). A Guide to the Birds of the West Indies. Princeton University Press, Princeton, NJ, USA. Close , 2 Collar, N. J. (2001). Family Trogonidae (Trogons). in Handbook of the Birds of the World, vol. 6: Mousebirds to Hornbills ( J. del Hoyo, A. Elliott , and J. Sargatal , Editors.). Lynx Edicions, Barcelona, Spain. pp 80–129. Close ).

Measurements (in mm) from Wetmore and Swales (1 Wetmore, A., and B. H. Swales (1931). The birds of Haiti and the Dominican Republic. United States National Museum Bulletin 155. Smithsonian Institution, Washington, DC, USA. Close ), given as means with range in parentheses. Female n = 4 and male n = 17.

Wing. Female 136.6 (132.6–141.0), male 135.2 (129.9–140.4).

Tail. Female 154.0 (150.0–161.0), male 154.0 (146.0–161.0).

Culmen from base. Female 16.5 (15.9–17.1), male 17.3 (16.4–18.4).

Tarsus. Female 16.4 (16.3–16.7), male 16.8 (15.0–18.4).

Mass

74.2 g (n = 1 female; 15 Johnsgard, P. A. (2000) Trogons and quetzals of the world. Smithsonian Institution Press, Washington, D.C., USA. Close ).