Muda em Pastor roseus

pedro121 escreveu:As duas aves observadas em Peniche tinham sinais de muda, especialmente a de 2012 em que era claro de semana para semana o desenrolar da muda.

pedro121 escreveu:Pelo que li na altura a muda decorre mais tarde que em Sturnus e os 2º anos em janeiro-fevereiro tem já o padrão dos adultos

pedro121 escreveu:mas o rosa é muito mais esbatido e vai sendo adquirido por desgaste, penso que o machos só adquirem a cor completa no 3 ano de calendário.

Gonçalo Elias escreveu:
Interessante. Quanto tempo estiveram na zona?

Gonçalo Elias escreveu:2º ano em Janeiro quer dizer 2ºcy ou 3º cy?

Gonçalo Elias escreveu:Em 27.12.1991 observei um P. roseus na Carrapateira, Algarve. Estava no meio de um bando enorme de S. unicolor. Na altura creio que identifiquei a ave como adulta, pois tinha dorso rosado e asas pretas, mas não percebia nada de mudas e muito menos sabia que a espécie fazia muda pós-juvenil completa. Acresce que a observação foi feita a alguma distância e já com luz de fim-de-tarde (após o por-do-sol), o que tornava difícil perceber bem todos os pormenores. O que eu estava a tentar a perceber é qual seria o aspecto de um imaturo nessa época do ano, para determinar (22 anos depois) se a minha avaliação da idade da ave estava correcta.

Gonçalo Elias escreveu:Entendo, mas se a muda pós-juvenil é completa, então não deveria haver diferenças entre juvenis e adultos uma vez concluída a muda... aliás creio que é isso que acontece com S. unicolor: uma vez concluída a muda, os juvenis são indistinguíveis dos adultos, mesmo na mão.

Taken from the BWP on CD-ROM: copyright Oxford University Press.

Moults

ADULT POST-BREEDING
Complete; in winter quarters. Most start August, on arrival in Indian subcontinent (Berg 1982b); those lingering in north either start there, or delay moult, e.g. one from Afghanistan, 15 October, heavily worn, but no moult (Paludan 1959); none of USSR birds moulting, though heavily worn: (Dementiev and Gladkov 1954). In India, starts July–August, completed by about October; tail starts relatively early, at primary moult score 5–10 (p2 or p3 in moult); secondaries start when p5–p6 in moult, completed shortly after regrowth of outer primaries (primary score 50); secondary moult frequently suspended, with 1–3 old ones retained, these either moulted in March or retained until next post-breeding moult (Naik and Naik 1969; Herroelen 1987).

POST-JUVENILE
Complete or almost so; 1–3(–5) juvenile secondaries (especially s6) or (rarely) some other feathers retained until c. 1•5 years old. Birds arrive in Indian winter quarters in juvenile plumage and moult there into 1st adult plumage from August or September, completing December (Naik and Naik 1969) or moult October (Sharpe 1890). Birds lingering in breeding area or straggling further north and west show marked individual variation in timing of moult, probably depending on condition of bird; either start at correct time, occasionally suspending moult when body condition deteriorating, or delay moult markedly; in winter quarters, a few birds markedly late also. Depending on local conditions, juveniles fledge mid-June to early August, mainly mid-July; birds in fully juvenile plumage encountered July (many localities), 21 August (Kashmir), 2–3 September (western Tibet), 16 September (Afghanistan), 27 September (Netherlands, plumage fresh), 5 November (Baluchistan), and 24 November (Netherlands), as well as in c. 12 of 13 birds recorded late August to early November in Britain. Birds with innermost primaries and some body feathers new and some more feathers in moult or with moult suspended occur 18 August (India), early October and 15 and 28 November (Britain), and up to February (Arabia). Inner 3–4 primaries (moult score c. 18–25), tertial coverts, and inner greater coverts new, p5 (p4–p6) and central tail-feathers moulting (tail starting with shedding of t1 from primary score c. 15), and body in early stages of moult in birds from September (several from Afghanistan and Pakistan), 20 October (Netherlands), and 28 October (India); inner 6 primaries and all greater coverts new in one from 22 November (Sri Lanka); inner 7 primaries, 4 pairs of tail-feathers, 2 secondaries, and all wing-coverts and tertials new, with p8–p9 (score 44), t5–t6, and s3–s4 growing and head and chest in full moult in one from 23 December (India); 5 birds in final stages of moult 2–23 January (Sri Lanka), singles just completed 21 February (Sri Lanka) or as late as 7 May (Sri Lanka). (Stresemann 1920; Paludan 1959; Roberts 1982; Holmes et al. 1985; Svensson 1992; RMNH, ZFMK, ZMA.) Thus, primary moult normally starts mid-August to early October, completing January–February, but a few birds start up to February and finish up to May.