Maritimas

Gonçalo Elias escreveu:
Oi Pedro, uma questão: pela tua experiência, como descreverias o estatuto do papagaio-do-mar nas nossas costas e, em especial na tua zona, em termos de:
- abundância
- fenologia (passagem ou invernante)
- proximidade à costa

Gonçalo Elias escreveu:Obrigado.

A propósito de literatura, recordo-me de ter lido num trabalho sobre as aves de Gibraltar que a espécie é muito abundante no estreito.

Gonçalo Elias escreveu:Certo Pedro mas eu escrevi "abundante" (creio que é este o termo usado no trabalho que li) e não "frequente".

pedro121 escreveu:

Gonçalo Elias escreveu:Certo Pedro mas eu escrevi "abundante" (creio que é este o termo usado no trabalho que li) e não "frequente".

Certo, e é de facto abundante, são milhares de aves, mas num espaço temporal muito curto.

BWP escreveu: Movements
HIGH-ARCTIC POPULATIONS
LOW-ARCTIC POPULATIONS
SOUTHERN POPULATIONS
Strongly dispersive. Essentially marine outside breeding season, keeping well offshore. Mid-ocean occurrences not rare (e.g. Rankin and Duffey 1948), due to transatlantic movements by some immature birds (see below)
Southern colonies occupied late March to mid-August, northern ones May to early September. On fledging, juveniles make their own way to sea and stay there until they begin to visit colonies again as pre-breeders. Pre-breeders of 4–5 years of age attend colonies again from April onwards, with progressively younger birds arriving as summer advances; most birds do not visit colony until 2 years old, and those 1-year-olds which visit do not appear until July–August, since they undergo wing moult in spring and early summer (M P Harris). Immatures frequently visit colonies other than their natal one, and some 20–25% of 1st-time breeders settle in a new colony; highly site-faithful thereafter (M P Harris; see also Myrberget 1973b, Harris 1976c, Petersen 1976a). Such inter-colony movements normally between adjacent groups of colonies, and emigration highest from colonies lacking room for expansion (M P Harris).
Winter distributions and summer ranges of immatures are poorly known, since relatively few ringing recoveries, especially from offshore zones. Occurs south to New Jersey in western Atlantic and to Morocco in eastern, with southern breeding populations being those which disperse furthest south in winter.

HIGH-ARCTIC POPULATIONS
(naumanni). Non-breeding distribution virtually unknown. Southernmost record concerns a November specimen from Vesterålen, Norway (Haftorn 1971). Hence probably remains in East Greenland Sea and adjoining waters (probably extending to northern Norway) where seas remain unfrozen. However, Thule (north-west Greenland) populations must move further south, since no wintering occurs north of Sukkertoppen in southern Davis Strait (Salomonsen 1967a).

LOW-ARCTIC POPULATIONS
(nominate arctica). Winter range extends south to c. 55°N in western Atlantic where Newfoundland seas are believed important for Canadian and west Greenland populations (Salomonsen 1967a; Tuck 1971). From extensive ringing in Norway (mainly Nordland), most recoveries in Norwegian waters and especially in south-west and south (Möre og Romsdal to Skagerrak). This distribution probably reflects regional trend in shooting of Alcidae, of which there is little in northern Norway; higher proportion of winter recoveries for 1st-year birds than for older ones may indicate greater vulnerability of former, or that older birds winter further offshore (Myrberget 1962c). Ringing at Lovunden colony (66°20'N, just south of Arctic Circle) showed birds having south-westerly trend towards Skagerrak, with minority penetrating into North Sea (Scotland, Helgoland Bight). In contrast, birds ringed only 250 km further north (Røst in Lofotens) produced fewer recoveries in southern Norway, but November–February recoveries of immatures far to the west, in Faeroes, Iceland, south-west Greenland, and 1 in Newfoundland (Myrberget 1973b). Data from other Norwegian colonies sparse, but support indication that Lofoten and Vesterålen birds are more likely to move out into Atlantic than birds from colonies south of Arctic Circle. Of 21 Newfoundland recoveries listed by Tuck (Tuck 1971), 18 were Icelandic birds, all 1st-winter and found 8 October–11 March; no other data on dispersal of Icelandic population (no recoveries in Greenland listed by Salomonsen 1971).

SOUTHERN POPULATIONS
(grabae). Ranges in winter south to c. 30°N and penetrates western Mediterranean (east to Italy). Most ringing data from British and Irish colonies, with 175 foreign recoveries to 1982. Birds ringed at east coast colonies (Fife, Northumberland) remained in North Sea all year, including birds found southern Norway in autumn and winter (Mead 1974; M P Harris). Birds ringed northern Scotland and Irish Sea also produced a small number of Norwegian recoveries in autumn and (later) further south in North Sea. Otherwise recoveries for these northern and western colonies indicated southward Atlantic movement by adults and immatures to Bay of Biscay, Atlantic coast of Iberia, and western Mediterranean; also recoveries in Morocco (7), Madeira (1), and Canary Islands (2). Immature birds found in summer from Bay of Biscay northwards to Faeroes and Iceland; many caught then in fishing nets, reflecting not only their inexperience but also their presence in areas of high marine productivity where also many fishermen, e.g. off Atlantic coast of Ireland (M P Harris). Some young birds move further west or northwest in Atlantic in winter: 4 Scottish 1st-winter birds found Newfoundland in December–January, and 2 Greenland recoveries in November (Scottish juvenile) and December (Welsh 4-year-old).
Recovery rates from ringing are particularly low in this species compared with other Alcidae, probably due to more offshore (pelagic) distribution. In British birds: Uria aalge 2.7%, Alca torda 3.0%, F. arctica 0.7%.

cardosohelder escreveu:Se as previsões se mantiverem eu estou lá

Gonçalo Elias escreveu:poderá ter a ver com o rumo do vento?

pedro121 escreveu:
e não estar sentir-se muito ao nível do mar

Paulfer escreveu:

pedro121 escreveu:
e não estar sentir-se muito ao nível do mar

Já agora, há previsões disso? Saber a altura do vento...  

Paulfer escreveu:

pedro121 escreveu:
e não estar sentir-se muito ao nível do mar

Já agora, há previsões disso? Saber a altura do vento...  

pedro121 escreveu:

Paulfer escreveu:

pedro121 escreveu:
e não estar sentir-se muito ao nível do mar

Já agora, há previsões disso? Saber a altura do vento...  

Podes mudar a altitude no menu.

http://earth.nullschool.net/#current/wind/surface/level/orthographic=-6.82,40.70,467

pedro121 escreveu:
Podes mudar a altitude no menu.

cardosohelder escreveu:
Mas a Gavia immer continua dentro do porto de Peniche.

cardosohelder escreveu:Não vi de manhã, mas voltei de tarde e estavam 4 dentro do porto.

A passagem estava um pouco mais intensa de tarde, comparativamente com a hora de manhã, mas quase só Morus

cardosohelder escreveu:Para fazer o resumo da manhã de hoje no Carvoeiro:

Apesar do vento forte de W/NW houve poucas aves, a amnhã resumiu-se a 8 S. pomarinus, alguns skuas, algumas rissa e poucas mauretanicus. Nada de alcídeos! (ou melhor, creio que passou 1, mas eu não o vi).
.