miércoles, 13 de mayo de 2015

Presumed 'Brown' Pied Flycatcher at Sevilla on May 2015

On 11 May 2015 José Luís Anguita observed and photographed what seemed a milk & coffee Pied Flycatcher Ficedula hypoleuca within a Seville, Andalusia, urban park. He took three photos (attached) and he described the sighting as follows:

Ayer encontré este papamoscas en un parque de Sevilla capital. Lo di por hembra de cerrojillo y no me fijé en su vuelo ocupado con las fotos...pero al verlas parece atípico. No sabemos si leucístico o alguna otra especie. Su ojo no es oscuro si te fijas, y es muy pálido. 

' I saw yesterday this flycatcher in a Seville park. I gave it as a female Pied and I did not pay attention to its flight as I was concentrated in taking the pictures... but once I saw them it seems atypical. We don't know if its a leucistic or another species. Its eye is not dark and it's very pale'

All 3 photos © J.L.Anguita




 

Once checked the photos it seems that the bird is pale indeed and that the colour is not bleached-related (feathers seem to be new, not worn). Therefore it is presumably an aberration-related subject.

According to van Grouw (2006) Dutch Birding 28: 79-89, the bird could be a 'Brown' aberration:

'Brown as aberration is defined as a qualitative reduction of eumelanin. In this mutation, the amount of pigment remains unchanged but the appearance of the eumelanin is changed (cf Kopf 1986). As a result of an inherited  incomplete oxidation of eumelanin, black feathers will turn dark brown. The phaeomelanin is unaffected'.


Contrast between paler mantle and brown feathering indicating 'pale female' could support this hypothesis since :  

'In nature, ‘brown’ males are very rare because they can only be born from a ‘brown’ mother and a normal father that is heterozygotous for this mutation (and of course from parents that are both ‘brown’). The chance for this to occur in nature is normally very minute.'

This is the first flycatcher of this kind known to the author.


Reference:

Anguita, JL 2015 Presumed 'Brown' Pied Flycatcher at Sevilla on May 2015 . Birds in Spain blog. http://birdspain.blogspot.com




1 comentario:

Màrius Domingo de Pedro dijo...

Jo ja el tinc, i dedicat!
No el deixeu escapar!