Mangrove Cuckoo Coccyzus minor

  • Order: Cuculiformes
  • Family: Cuculidae
  • Monotypic
  • Authors: John D. Lloyd
Sections

Appearance

Distinguishing Characteristics

Mangrove Cuckoo is a moderately large cuckoo; both sexes are similar in appearance. The dorsal surfaces are uniformly grayish brown. The ventral surfaces range in color from a tawny buff to a dingy cream, with the vent and belly darkest in color and the chin lightest. The ventral surfaces of the outer rectrices are black with prominent white tips. A black mask surrounds the eye and extends into the auricular region; the mask is often highlighted by a white "eyebrow" that may extend along its superior edge. The relatively long, decurved bill is two-toned, with a black maxilla and a largely yellow lower mandible that is tipped in black. The eyering ranges from gray during the breeding season to a bright yellow during the nonbreeding season. Juveniles are generally similar in appearance to adults, but with buffy edges to remiges and coverts and tail feathers that lack the bold black-and-white patterning seen in adults.

Similar Species

Yellow-billed Cuckoo (C. americanus) has less pronounced auricular and loral mask, shows rufous on inner webs of primaries, has yellow extending to at least base of upper mandible, and has white underparts without any hint of a buffy wash. The color pattern on the outer rectrices also differs: on Mangrove Cuckoo, the tips of the outer rectrices are white, becoming black proximally on both inner and outer webs; on Yellow-billed Cuckoo, the tips of the outer rectrices are white becoming black proximally on only the inner web and remaining white on the outer web until closer the feather base. On birds viewed ventrally, this lends a white edged appearance to the tail of Yellow-billed Cuckoo, especially on the proximal portion.

Dark-billed Cuckoo (C. melacoryphus) has an entirely black bill.

Cocos Cuckoo (C. ferrugineus), endemic to Cocos Island, Costa Rica, has rusty flight feathers, coverts, and nape, which contrast with the gray cap. The white spots on the distal ends of r2-r5 are much larger, sometimes overlapping when the tail is folded so that little black shows on the ventral surface.

Detailed Description

A robust bird with a tail as long as, or longer than, the body. Uniformly fuscous (7F4 in the Methuen standard) dorsally from the foreceown to the rump and to the distal end of the innermost rectrices. Distal end of innermost rectrices sometimes darkening to a charcoal gray, both feather vane and web. Primaries and secondaries, and coverts, are also fuscous, lending a uniform appearance to a perched bird viewed from the rear. Ventral surface of the innermost rectrices (r1) somewhat lighter in color than the dorsal surface, but otherwise similar. Ventral surface of the outer rectrices (r2-r5) black with large white patches at distal end that extend across inner and outer webs. Ventral plumage variable in color, ranging from a dingy cream (4A2 in the Methuen standard) to a deep, tawny buff that is almost chestnut in color (approximately 5B5 in the Methuen standard). Most individuals have richest color on the thigh feathers and around the vent, and become increasingly pale cream to dirty white through the breast, throat, and chin. However, some individuals, especially birds from Guadeloupe and Dominica, show deep buff color throughout the ventral surface, whereas others, especially birds from the Cayman Islands, Florida, and the Bahamas, show almost none. Ventral color appears to fade, so that recently molted individuals tend to show richer colors than individuals in worn plumage. Most birds also show a light gray wash on the sides adjacent to the bend of the wing, often extending across the breast and giving a smudgy appearance. A black mask extends from the lores to the auricular region, generally encircling the eye but variable in width. For almost all individuals, the mask extends further below the eye than it does above, and in some cases the superior edge of the mask does not reach the top of the eye. Almost always, the mask is more pronounced posterior to the eye. Sometimes a thin, white eyebrow is superior to the mask. When present, it tends be narrowest but most distinct above the eye, becoming wider but more diffuse to the posterior.

Hatch-year plumage is generally similar, although newly independent young are noticeably pale – even around the vent and on the thighs – and small. Older hatch-year birds resemble adults in that they gain at least some buffy color on the ventral surface, which suggests that a presupplemental molt of some body feathers may occur prior to the first prebasic molt. Hatch-year birds differ from adults in the pattern of the outer rectrices (r2-r5). In hatch-year birds, the ventral surface of these feathers is much lighter than in adults, resembling very closely the fuscous color of the dorsal surface, and the distal patches are indistinct because they are gray rather than white and so provide little contrast with the darker, proximal portion of the feather.

Molts

Molt pattern of Mangrove Cuckoo is poorly known, but is assumed to follow that of other New World Coccyzus. Presumably has a single, incomplete-to-complete molt each year. In strongly seasonal portions of its range, molt occurs in the middle to late wet season (e.g., October or November in the Bahamas) following breeding. In relatively aseasonal tropical areas, where breeding could occur year round, molt may be protracted or may occur at different times of year. Of nine museum specimens examined that were molting when collected, 1 was collected in September (Guadeloupe), 4 in October (Guadeloupe, Dominica, Bahamas, and Florida), 2 in November (Bahamas, Tortola), and 2 in January (both from Haiti).

A few secondaries, rectrices, and, occasionally, primaries and primary coverts may be retained during the first (hatch-year) and subsequent molts. According to Pyle (1997), flight feather replacement is irregular: the inner four primaries are replaced distally, whereas the outer six primaries are replaced proximally from p10 to p5. In addition, feather replacement is not sequential within these sequences, and often every other feather is replaced, producing sequences such as p10-p8-p6-p9-p7-p5 (Pyle 1997).

Bare Parts

Tarsi are gray to bluish gray when alive, apparently darkening to black in museum specimens. Maxilla black. Distal end of mandible is black, becoming yellow proximally. Extent of yellow is variable, but generally covers the proximal 75% of the lower mandible. Eye-ring color varies from yellow to charcoal gray. Pyle (1997) suggested that the orbital ring was gray in hatch-year or early second-year birds, becoming yellow after the first winter and remaining yellow thereafter. However, an individual captured in Florida by the author in March presented with a yellow eyering; the same individual was resighted and photographed in April and showed a gray eyering with no evidence of yellow (J.D. Lloyd, personal observation). Another individual captured in early April presented an eyering that was intermediate in color and appeared to be changing from yellow to gray. In subsequent observations, this individual showed a gray eye-ring without traces of yellow. None of the birds captured (n = 13) or observed in this population between April and August presented with a yellow eyering. Clearly, the trait is not age related, but instead appears to vary seasonally, at least in some populations, where it changes from gray during the breeding season to yellow during the nonbreeding season.

Measurements

The sexes are similar in size. Individuals from the Lesser Antilles appear larger than individuals from elsewhere in the range based on published measurements, in keeping with observations of some early collectors (e.g. Nicholll 1904).

Measurements of Mangrove Cuckoo from specimens collected throughout the geographic range of the species.  Data originally split by subspecies, but following Banks and Hole (1991) specimens here are identified only by location of collection.  Where sample size (N) is more than one, values are means as calculated and reported by the source or ranges as reported by the source.   Locality is the collection site as reported by the source (all data from Ridgway 1916, except aPeters 1927, bWetmore and Swales 1931, and cvan Rossem).
Locality

Wing

chord (mm)

Tail

length (mm)

Exposed

culmen (mm)

Tarsus length (mm) Sex N
Nata, Cocle, Panama 128.5 160 28 29.5 M 1
Yucatan, Mexico 129 156.5 30 29 M 1
Tamaulipas, Mexico 128.5 161 29 28 M 1
Costa Rica (eastern) 133.5 158.5 28.5 29.5 F 1
Nicaragua (eastern) 135.5 163 28.5 29 F 1
Yucatan, Mexico 129.5 N/A 28.5 28.5 F 1
Costa Rica (western) 140.8 161.7 30 29.7 M 6
Nicaragua (western) 138.5 161.7 31 29.7 M 2
Tepic, Mexico 139.2 160 30 28 M 2
Tres Marias Islands, Mexico 144 168 29 29 M 1
Costa Rica (western) 142.1 163.7 29.4 29.8 F 6
Nicaragua (western) 141 168 30 29 F 4
Swan Islands, Honduras 136.7 174.2 28.5 29 M 2
Swan Islands, Honduras 141 178 27 28 F 1
Isla de Providencia, Colombia 144 164.8 29 29.7 M 3
San Andres, Colombia 136 169.2 29 28.7 M 2
Cozumel, Mexico 132 154 28.4 N/A N/A 2
 Florida, USA 137 167.2 27 28 M 2
Rum Cay, Bahamas 133 163 28 27 M 1
San Salvador, Bahamas 133.4 163.3 27.3 28.6 M 5
"Abaco Island", Bahamas 130.5 156 27.5 27 M 1
"Caicos Island", Bahamas 125  150.5  25 29 M 1
"Inagua Island", Bahamas 131.2 162.3 27.8 28.5 M 3
Andros Island, Bahamas 132.7 159.7 26.5 26.7 M 2
New Providence, Bahamas 134.6 159.8 27.5 27.7 M 4
Eleuthera Island, Bahamas 130.5 160 27.5 28.7 M 2
Florida, USA 138 164.5 29 29.5 F 2
Rum Cay, Bahamas 137.5 161 30 28 F 1
San Salvador, Bahamas 137 153.2 28 29.7 F 2
"Inagua Island", Bahamas 133.4 165.3 27.8 29 F 5
New Providence, Bahamas 134.6 159.8 27.5 27.7 F 5
Eleuthera Island, Bahamas 138.5 164.5 27 28 F 1
Long Island, Bahamas 131 N/A 29 25.5 F 1
Berry Island, Bahamas 128 158 28 29 F 1
Guantanamo, Cuba 137 157 27 27.5 F 1
Grand Cayman, Cayman Islands 133.3 162.9 29 28.9 M 7
Jamaica 134.9 165.4 27.5 28.1 M 10
Haiti 130.7 158.7 27.4 27.8 M 10
Puerto Rico 131.4 162.6 26.3 27.5 M 6
Vieques, Puerto Rico 126.5 153.5 26.5 28.5 M 1
Mona, Puerto Rico 133.5 149.5 27.2 25.5 M 2
Saint Thomas, U.S. Virgin Islands 134.5 151.5 26.5 27.5 M 1
Grand Cayman 133.3 161.4 28.5 28.7 M 6
Jamaica 136.3  167.5  27.9 28.5 F 10
 Haiti  133.3  160.2  27.8  28.3  F 9
 Puerto Rico  132.9  164.5  27.4  30.9  F  8
 Vieques, Puerto Rico  133.5  163.5  27  28  F  1
 Mona, Puerto Rico  132.3  155  28  28.5  F  3
 Culebra, Puerto Rico  132.7  163  28.2  28  F  3
 Culebrita, Puerto Rico 133.5  164.5  27.5  28.5  F  1
 Saint John, U.S. Virgin Islands  127  161.5  28  27  F  1
 Virgin Gorda, British Virgin Islands  138.5  169.5  27  29.5  F  1
 Dominican Republica  126.3  163.7  26.3  26.3  M  11
 Dominican Republica  127.7  163.2  26.1  27.3  F  5
 Haiti/Dominican Republicb  125.1  154.8  27.6  27.2  M  7
 Haiti/Dominican Republicb  128.1  151.9  27.7  27.9  F  6
 Barbuda  138.7  161.5  29  27  M  2
 Antigua  133.4  160.7  29.2  29.8  M  9
 Barbuda  146.7  159.5  28.7  29.2  F  2
 Antigua  139.4  161.7  28.9  29.2  F  9
 Saint Vincent  146.2  171  30.8  30.8  M  2
 Saint Lucia  144.5  169  30  30.5  M  1
 Saint Vincent  142.5  173.7  30.3  30.6  F  4
 Saint Lucia  145  182.2  29.7  61  F  2
 Dominica  142.7  164.9  30  60.1  M  4
 Guadeloupe  141.7  163  27.7  29.7  M  3
 Martinique  141  164.9  29.3  29.7  M  1
 Dominica  143.4  165.9  30.1  30.1  F  4
 Grenada  140.7  169.2  31.5  31.5  M  6
 Union Island, Saint Vincent and the Grenadines  135.8  164.1  30.9  30.9  M  6
 Bequia, Saint Vincent and the Grenadines  137.8  171.2  30.7  30.7  M  3
 Carriacou, Grenada  136.5  159.2  29.2  29.2  M  2
 Grenada  140  166.5  31  31  F  3
 Union Island, Saint Vincent and the Grenadines  139.1  164.5  30  30  F  4
 Carriacou, Grenada  135.5  164  30  30  F  1
 Aruba  131.5  159  28  29.5  F  1
 northern South Americac  128-140 142-158  28-32  27-30.5 N/A  7
Measurements of male and female Mangrove Cuckoos, averaged across all localities. Numbers in parentheses are 95% confidence intervals.
Sex Wing chord (mm) Tail length (mm) Exposed  culmen (mm) Tarsus (mm)
Female 136.1 (134.3 - 137.8) 163.6 (161.5 - 165.7) 28.4 (28.1 - 28.8) 28.9 (28.5 - 29.2)
Male 135.1 (133.3 - 136.9) 162.1 (160.3 - 163.9) 28.5 (28.0 - 29.0) 28.7 (28.3 - 29.1)


Measurements of Mangrove Cuckoos, averaged across all specimens for each locality. Numbers in parenetheses are 95% confidence intervals.
Region Wing chord (mm) Tail length (mm) Exposed culmen (mm) Tarsus length (mm)
Florida/Bahamas 133.4 (131.6 - 135.2) 160.7 (158.5 - 162.8) 27.7 (27.1 - 28.2) 28.1 (27.6 - 28.7)
Central America (including offshore islands) 137.0 (134.3 - 139.6) 164.4 (161.3 - 167.2) 29.1 (28.6 - 29.5) 29.0 (28.7 - 29.3)
Greater Antilles 131.9 (130.4 - 133.5) 160.2 (157.9 - 162.5) 27.4 (27.1 - 27.7) 28.0 (27.5 - 28.5)
Lesser Antilles 140.6 (138.9 - 142.2) 166.1 (163.6 - 168.7) 29.8 (29.4 - 30.3) 30.1 (29.6 - 30.5)

Recommended Citation

Lloyd, J. D. (2014). Mangrove Cuckoo (Coccyzus minor), version 1.0. In Neotropical Birds Online (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/nb.mancuc.01