Plumages, Molts, and Structure

Red-crowned Parrot has 10 full-length primaries (numbered distally, from innermost p1 to outermost p10), 10 secondaries (numbered proximally, from innermost s1 to outermost s7 and including 3 tertials, numbered t1 to t3 distally), and 12 rectrices (numbered distally on each side of the tail, from innermost r1 to outermost r6, on each side of the tail). Little or no geographic variation in plumage reported (see Systematics). The following plumage descriptions are based on those of Ridgway (3 Ridgway, R. (1916). The birds of North and Middle America, Pt 7. United States National Museum Bulletin 50. Close ), Foreshaw (4 Forshaw, J. M. (1989). Parrots of the world. 3rd ed. Melbourne, Australia: Lansdowne Editions. Close , 5 Forshaw, J.M. (2006). Parrots of the World: an Identification Guide. Princeton University Press, Princeton, New Jersey. Close , 6 Forshaw, J. M. (2010). Parrots of the World. Princeton University Press, Princeton, NJ, USA. Close ), Howell and Webb (7 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 ), Collar (8 Collar, N. J. (1997). Family Psittacidae (parrots). In Handbook of the Birds of the World. Volume 4. Sandgrouse to Cuckoos (J. Del Hoyo, A. Elliott, and J. Sargatal, Editors). Lynx Edicions, Barcelona, Spain. pp. 280–477. Close ), and Juniper and Parr (9 Juniper, T., and M. Parr (1998). Parrots: A Guide to the Parrots of the World. Pica Press, Robertsbridge, UK. Close ), along with examination of Macaulay Library images; see Pyle (10 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, CA, USA. Close ) for specific age-related differences. See Molts for molt and plumage terminology. Sexes are similar in plumage, but may show slight average differences in Definitive Basic Plumage; definitive appearance is assumed at the Second Basic Plumage.

Natal Down

Occurs in the nest cavity, primarily in May‒July. Hatchlings are covered with sparse whitish down.

Juvenile (First Basic) Plumage

Occurs primarily in July‒October. Juvenile Plumage resembles Definitive Basic Plumage, but has red restricted to a band above forehead. Sides of crown and neck with little or no blue and, when present, it is duller blue than in later plumages (11 Wozniak, S., and W. Lantermann (1984). Breeding the Green-cheeked Amazon Parrot Amazona virdigenalis at the ornithological institute, Oberhausen, Germany. Aviculture Magazine 90:195–197. Close ). Juvenile primaries and rectrices are narrower and more tapered at the tips than basic feathers (10 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, CA, USA. Close ). See also Bare Parts for differences in iris color by age (duller and duskier in juveniles than in adults).

Formative Plumage

Occurs primarily in October (when fresh) to August (when worn). Similar to Definitive Basic Plumage but duller (ECE, SK). The extent of red in the crown also appears to average less than in older birds but may occasionally show extensive red in the crown (SK); study is needed on variation in the red in the crown by both age and sex (see Definitive Basic Plumage, below). Otherwise, Formative Plumage is best identified by retained juvenile wing and tail feathers. Some proximal upperwing lesser coverts can be replaced, brighter green, contrasting with duller juvenile distal and greater coverts. Retained juvenile primaries and secondaries are narrower and more tapered at the tips, and are relatively worn and brownish as compared with basic feathers. Retained juvenile rectrices are narrower than basic rectrices, more worn, and duller green or yellowish. Primaries and secondaries lack molt clines shown by definitive basic birds (see below and 12 Pyle, P. (2013). Evolutionary implications of synapomorphic wing-molt sequences among falcons (Falconiformes) and parrots (Psittaciformes). Condor 115:593–602. Close , 10 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, CA, USA. Close ). In addition, iris color may gradually change from grayish to yellow during the first year (see Bare Parts).

Second Basic Plumage

This plumage can be identified in occasional birds following incomplete Second Prebasic Molts. Plumage resembles Definitive Basic Plumage but one or more juvenile primaries and/or secondaries may be retained among p1-p2, p9-p10, s1-s2, and/or s6-s8; these are narrow and tapered, brownish, worn, and contrast markedly with replaced feathers (10 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, CA, USA. Close ). The extent of red and blue feathering of the head may also average less extensive than in later plumages but more extensive than in Formative Plumage; study is needed. See right-hand image under Molts.

Definitive Basic Plumage

Occurs primarily in October (when fresh) to August (when worn). The forehead, crown, and lores are a uniform bright red (the bases of feathers are yellowish). The extent of this red relative to the eye is variable, with the center crown often mottled red and green. The hind crown and nape are green, the feathers tipped with black, most broadly on the lower nape, extending to the sides of the neck and breast. Behind the eyes is a broad stripe are violet blue, extending more narrowly to the sides of the neck where the feather bases are green. The sides of the head are uniformly bright green (brighter than elswhere) or with a brighter green wash to the auriculars. The remainder of upperparts and wing coverts are green, the back feathers and lesser coverts washed or scalloped dusky or bluish gray when worn and the greater and median wing coverts are edged or margined with lighter green. The rectrices are green on the basal half (both webs), light yellowish green terminally (particularly on inner web), except that the middle pair is almost wholly green, and the outermost feather usually with basal half of outer web are edged with dusky bluish, becoming dull reddish terminally. The primary coverts, alula, and remiges are blackish, the primary coverts and alula broadly fringed green, the outer primaries with bright green outer webs basally, the inner primaries and secondaries with deep blackish-blue outer webs at the tips, and the bases to the outer webs of outermost secondaries (s1–s5) bright red forming a distinct red patch to the upperwing (but not the underwing) in flight. The bright green sides of the head sometimes extends to the chin and throat. Otherwise, underparts are green, often lighter and more yellowish than the upperparts, especially on the sides, flanks, and femoral feathers. The underwing coverts and undersides of flight-feathers are green, the primary coverts and greater coverts often yellower forming a diffuse yellow stripe to the mid portion of the underwing in flight.

From above, the primaries and secondaries are broader and more squared than juvenile feathers, and rectrices are also broader than in juvenile feathers. Primaries and secondaries show molt clines, with middle primaries (p6 or p5) more worn and gradually freshening in both directions to p1 and p10, and the middle secondary (s5) most worn and showing gradually freshening outward (toward s1) and inward toward the tertials (see Molts and 12 Pyle, P. (2013). Evolutionary implications of synapomorphic wing-molt sequences among falcons (Falconiformes) and parrots (Psittaciformes). Condor 115:593–602. Close , 10 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, CA, USA. Close ). Following incomplete prebasic molts, Staffelmauser patterns can result as reflected by various patterns of older and newer basic feathers among primary and secondary tracts; such patterns can indicate birds in Third Basic Plumage or older (10 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, CA, USA. Close ).

Slight dichromatism between sexes has been reported in the extent of the red forehead and crown. Females average less red, rarely extending beyond the center of the crown, but this is variable and not always reliable for sexing (13 Peterson, R. T., and E. L. Chalif (1989). Aves de México: Guía de Campo. Editorial Diana, Mexico City, Mexico. Close , 14 Kalodimos, N. P. (2013). The status and comparative nesting phenology of the red-crowned amazon on O’ahu, Hawai’i. ‘Elepaio 73:1–3. Close , ECE, SK), although many mated pairs show evident dichromatism in Definitive Basic Plumage (see images below). Study is needed on variation in the extent of red in the crown according to both age (Juvenile, Formative, or Definitive Basic Plumages) and sex. Individual plumage differences can be stable from year to year and may be used for identification purposes (15 Enkerlin-Hoeflich, E. C. (1995). Comparative ecology and reproductive biology of three species of Amazona parrots in northeastern Mexico. Ph.D. dissertation, Texas A&M University, College Station, TX, USA. Close ).

Aberrant Plumages

Anomalously colored individuals are not uncommon in the wild (ECE, SK). Variations include yellow feathers on several parts of the body, especially the neck and head, and the bend of the wing is sometimes red. It is unknown if some color variations may be due to hybridization with congeners. Xanthochromatism is an unusual yellow appearance affecting most or all feathers caused by a genetic mutation in wild birds, but is extremely uncommon; these individuals are more commonly bred in aviculture and are termed “lutinos.”

Molt and plumage terminology follows Humphrey and Parkes (16 Humphrey, P. S., and K. C. Parkes (1959). An approach to the study of molts and plumages. Auk 76(1):1–31. Close ) as modified by Howell et al. (17 Howell, S. N. G., C. Corben, P. Pyle, and D. I. Rogers (2003). The first basic problem: a review of molt and plumage homologies. Condor 105:635–653. Close ). As in most or all Psittacids, Red-crowned Parrot shows a Complex Basic Molt Strategy, with a partial preformative molt and complete prebasic molts, but no prealternate molts (10 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, CA, USA. Close ).

Prejuvenile Molt

The Prejuvenile Molt occurs in the nest cavity, primarily in May‒July among wild populations. There is little information on this molt in the wild but for two chicks reared in captivity, “first feathers appeared at the beginning of the fifth week,” by week 8 the chicks were “nearly fully fledged,” and the complete “development of the young birds took about nine weeks” (11 Wozniak, S., and W. Lantermann (1984). Breeding the Green-cheeked Amazon Parrot Amazona virdigenalis at the ornithological institute, Oberhausen, Germany. Aviculture Magazine 90:195–197. Close ).

Preformative Molt

Partial, primarily in the first 2‒3 months or more following fledging, primarily in August‒December among wild populations. As in most or all other Psitaccids, it includes the body feathering and some proximal upperwing secondary coverts but no primary coverts, remiges, or rectrices (10 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, CA, USA. Close ).

Definitive Prebasic Molt

Incomplete to complete, primarily following breeding in July‒October among wild populations but may occur at other times of year. Primaries and secondaries are replaced from nodes at p5‒p6 and at s5, followed by bidirectional replacement from these nodes within each tract (12 Pyle, P. (2013). Evolutionary implications of synapomorphic wing-molt sequences among falcons (Falconiformes) and parrots (Psittaciformes). Condor 115:593–602. Close , 10 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, CA, USA. Close ). Initiation of primary molt varies between p5 and p6 in parrots, including within species, suggesting that the node's position may be fluid within a defined area along the alar tract (12 Pyle, P. (2013). Evolutionary implications of synapomorphic wing-molt sequences among falcons (Falconiformes) and parrots (Psittaciformes). Condor 115:593–602. Close ); Macaulay Library images suggest that molt can initiate at p5 in some birds (see left-hand image under Definitive Basic Plumage and those below). Sequence of rectrix replacement poorly known, but these are generally replaced distally from the central rectrices (r1) on each side of the tail, with some variation probable; e.g., the outer rectrices (r6) may molt before central rectrices (r3‒r5) as occurs in other birds (8 Collar, N. J. (1997). Family Psittacidae (parrots). In Handbook of the Birds of the World. Volume 4. Sandgrouse to Cuckoos (J. Del Hoyo, A. Elliott, and J. Sargatal, Editors). Lynx Edicions, Barcelona, Spain. pp. 280–477. Close ). The Second Prebasic Molt likely averages earlier in timing among wild populations than later prebasic molts due to the lack of breeding constraints, complete molts in this species may suspend for breeding, especially in females, and molts may also be incomplete, with outer or inner feathers among either or both the primary and secondary tracts retained during and otherwise complete molt sequence (10 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, CA, USA. Close ). Incomplete molts appear to set up a Staffelmauser (or stepwise) molting pattern, whereby a prebasic molt initiates where the previous molt arrested, at the same time new sequences initiating, a pattern that can lead to various patterns of retained and replaced remiges after several prebasic molts (12 Pyle, P. (2013). Evolutionary implications of synapomorphic wing-molt sequences among falcons (Falconiformes) and parrots (Psittaciformes). Condor 115:593–602. Close , 10 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, CA, USA. Close ).

This replacement pattern is unique to parrots and falcons and may indicate an ancestral molting pattern evolved before parrots and falcons diverged. The strategy may have developed in order to replace all remiges more quickly in these species, which rely heavily on flight ability, without incurring large gaps in the wings (12 Pyle, P. (2013). Evolutionary implications of synapomorphic wing-molt sequences among falcons (Falconiformes) and parrots (Psittaciformes). Condor 115:593–602. Close ).

Bill and Cere

Bill dull cream-yellow to whitish, paler terminally (3 Ridgway, R. (1916). The birds of North and Middle America, Pt 7. United States National Museum Bulletin 50. Close ); also described as yellowish horn (4 Forshaw, J. M. (1989). Parrots of the world. 3rd ed. Melbourne, Australia: Lansdowne Editions. Close ) or pinkish with base of the upper mandible smoother and brighter cream to yellow. Dark gray blotches or dusky marks on the bill occur regularly and appear to be more prevalent in juveniles than adults (see images under Juvenile Plumage). The cere is purplish pink.

Iris and Facial Skin

In Juveniles the iris is "greenish-grey” (11 Wozniak, S., and W. Lantermann (1984). Breeding the Green-cheeked Amazon Parrot Amazona virdigenalis at the ornithological institute, Oberhausen, Germany. Aviculture Magazine 90:195–197. Close ) or washed dusky up to 6 months after fledging. In adults, the iris is yellow to (most often) medium-dark yellowish orange; individual variation perhaps relates to age (see Plumages). The orbital ring is whitish to light bluish gray.

Tarsi and Toes

The legs and feet are gray.

Linear Measurements

All measurements are from Tobias et al. (1 Tobias, J. A., C. Sheard, A. L. Pigot, A. J. Devenish, J. Yang, F. Sayol, M. H. Neate‐Clegg, N. Alioravainen, T. L. Weeks, R. A. Barber, P. A. Walkden, et al. (2022). Avonet: Morphological, ecological and geographical data for all birds. Ecology Letters 25:581–597. Close ) and Forshaw (4 Forshaw, J. M. (1989). Parrots of the world. 3rd ed. Melbourne, Australia: Lansdowne Editions. Close ):

• Culmen length: 33.5 mm (range 32.2–34.2, n = 5).
• Bill length (tip to nares): 27.7 mm (range 25.4–31).
• Bill width: 16.4 mm (n = 5).
• Bill depth: 27.5 mm (n = 5).
• Wing length: 202 mm (range 186–213).
• Tail length: 103.5 mm (range 90–116).
• Tarsus length: 22.3 mm (range 18.8–25).

Mass

Captive adults averaged 316 g (range 293–345, n = 13); fledglings in last week prior to fledging, 295 g (range 277–318, n = 20; ECE). Wild adults captured in southern Texas averaged 309 g (range 263–354, n = 6; SK).