OcellsOsona.Id

Cotxa atípica (Vic, 27/11/2005; Josep Maria Puig)  :: Atypical Redstart (Vic, 27/11/2005;  Josep Maria Puig)

Cotxa atípica (Vic, 27/11/2005; Josep Maria Puig)  :: Atypical Redstart (Vic, 27/11/2005;  Josep Maria Puig)

Fotografies :: Pictures: Josep Maria Puig

Comentaris :: Comments: Laurens B Steijn

:: El 27/11/2005 en Ramon Prat va trobar una cotxa Phoenicurus sp. que en un principi va portar alguns problemes d'identificació incloent algunes opcions com la d'un possible híbrid de cotxa fumada P.ochruros i cotxa cua-roja P.phoenicurus. S'observà com a mínim fins el 05/02/2006. Aquí es recullen alguns comentaris on s'explica per què finalment quedà identificada com a cotxa fumada.

:: On 27/11/2005 Ramon Prat found a Redstart Phoenicurus sp. that first gave some id problems with possibilities like a supposed hybrization of Black Redstart P.ochruros and Common Redstart P.phoenicurus. It was observed at least until 05/02/2006. Here you'll find some comments explaining why it was finally identified as a Black Redstart.

Cotxa atípica (Vic, 27/11/2005; Josep Maria Puig)  :: Atypical Redstart (Vic, 27/11/2005;  Josep Maria Puig)

"It does look strange indeed. It looks a little bit like ssp ochrurus (also has orange lower belly), but that ssp lacks the white wingpatch and is darker overall, especially on the upperparts. The white wingpatch is typical for Black Redstart ssp gibraltariensis. From what I can see, the wingformula and primary spacing is also typical for Black Redstart. I don't think it is a hybrid Black x Common. Where the atypical colouring comes from is hard to say." (Laurens Steijn 15/12/2005)

Cotxa atípica (Vic, 27/11/2005; Josep Maria Puig)  :: Atypical Redstart (Vic, 27/11/2005;  Josep Maria Puig)

"Actually, other than the amount of red on the underparts, I see no reason why Common Redstart is involved. Colouration of the upperparts, extend of the white wingpatch and primary spacing all point towards Black Redstart. In figure 3 [in Steijn (2004)] two out of 17 values (c 12%) of Hybrid Black x Common Redstart show a spacing ratio similar to Black Redstart. Both values came from breeding experiments and I haven't seen any wild birds approaching the spacing ratio of Black Redtstart. However, it is of course possible." (Laurens Steijn 17/12/2005)

Esquerra: espai entre primàries de la cotxa :: Left: primary spacing of the Redsart

Dreta: espai entre primàries d'una cotxa fumada Phoenicurus ochruros típica per comparació (Vic, 30/10/2004; M.Rodríguez) :: Right: primary spacing of a typical Black Redstart Phoenicurus ochruros for comparision (Vic, 30/10/2004; M.Rodríguez)

"Also note individual variation on adult male Black Redstart ssp gibraltariensis. This text is from BWPi:  Some individual variation in colour of body: of 50 birds in worn plumage examined from central Europe (RMNH, ZFMK, ZMA), 2% had pronounced white patch on forehead; 8% had belly and vent tinged rufous instead of grey-white (rather like nominate ochruros, but much less pure and extensive than phoenicuroides and rufiventris); 58% had upperparts uniform medium-grey (though often tinged darker grey on mantle and scapulars), 36% had much black visible on feather-centres of lower mantle and scapulars (or almost completely black), 6% had hindneck, mantle, and scapulars virtually black (and breast and upper belly more extensively black also), resembling Iberian aterrimus." (Laurens Steijn 17/12/2005)

Cotxa atípica (Vic, 27/11/2005; Josep Maria Puig)  :: Atypical Redstart (Vic, 27/11/2005;  Josep Maria Puig)

Referències :: References

Steijn, L B 2005. Eastern Black Redstarts at IJmuiden, the Netherlands, and on Guernsey, Channel Islands, in October 2003, and their identification, distribution and taxonomy. Dutch Birding 27: 171-194.