miércoles, 3 de diciembre de 2014

Aythya nyroca x fuligula [Hybrid Ferruginous x Tufted Duck]

On 20 November 2014 a female presumed hybrid Ferruginous x Tufted Duck was seen at Cal Tet lagoon, Llobregat Delta, El Prat de Llobregat, Barcelona (Ricard Gutiérrez, Ferran López, C.Llopis). The record appears in the 'Novetats Ornitològiques' Consorci Delta del Llobregat blog as follows:

Aythya nyroca x Aythya fuligula
Morell xocolater x Morell de plomall - Ferruginous Duck x Tufted Duck 

1 ex. suposadament híbrid a cal Tet el 20.XI (R. Gutiérrez, F. López, C. Llopis). L'exemplar mostra característiques de les dues espècies: cap rectangular i plomall amb tons axocolatats, plomes del pit color xocolata, infracobertores caudals i posteriors de color blanc, flancs de color xocolata brut, etc...

Ferran López, observer of the bird and manager of the blog quoted (see above in catalan): 'The bird shows characters of both species: rectangular head and the tuft with chocolate tones, brown tones in the breast, white undertail and rear coverts, dirty chocolate flanks etc...

Despite no telescope was available, a video and a few record shots were obtained using hand-held binoscoping technique from the cal Tet hide window and are included below. Most of the characters outlined above can be clearly noted.

Presumed Aythya nyroca x fuligula ♀  (lower right side of the photo). Cal Tet Lagoon, Llobregat Delta, Barcelona 20.11.2014 © Ricard Gutiérrez

Presumed Aythya nyroca x fuligula ♀  Cal Tet Lagoon, Llobregat Delta, Barcelona 20.11.2014 © Ricard Gutiérrez

McCarthy (2006) Handbook of Avian Hybrids of the World lists hybrids for Aythya nyroca with A.valisineria, Bucephala clangula, Marmaronetta angustirostris, Netta erythroptalma, N.peposaca, N.rufina. But also for Aix sponsa, Anas acuta, A.clypeata, A.platyrhynchos, Aythya baeri, A.collaris, A.ferina, A.innotata, A.marila, A.novaeseelandiae and A.fuligula.

Regarding the latter, this crossing is reported in Eurasia for both ♂ and ♀ amd the hybrids are said to be fairly common, accounting for a 5% of all waterfowl hybrids reported for Western Central Europe (Randler in McCarthy op.cit.). However, these authors refer that most of the reported hybrids are males (such as these birds -also including two presumed females - from the UK).

Other hybrids involving Aythya nyroca have been seen previously in the Llobregat delta (e.g. this from february 2012 with Pochard reported at Consorci Delta del Llobregat Blog here) but this A.fuligula x nyroca is the first known in the area as far as we know.

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