photo sharing and upload picture albums photo forums search pictures popular photos photography help login
Mark B Bartosik | profile | all galleries >> From the field - current news photoblog >> Black Skimmer - 3 aberrant females (“Brown” color mutation): history of this find, important close-up and comparison photos. tree view | thumbnails | slideshow

Black Skimmer - 3 aberrant females (“Brown” color mutation): history of this find, important close-up and comparison photos.

Fulton-Rockport shore: July 31, 2010 - I found 1 aberrant female, August 1, 2010 - I found 2 more aberrant females.

Other skimmer photos (of the adults and juveniles) presented here for a comparison were taken at the same location during the same days (at similar lighting conditions) as aberrant females.

August 4: Hein van Grouw after examination of my photographs, based on sex, plumage, bill and leg coloration agreed that it is safe to assume that this aberration is indeed caused by the mutation Brown (qualitative reduction of eumelanin). Hein van Grouw is an expert in this field and author of the publication (2006): “Not every White Bird is an Albino: sense and nonsense about colour aberrations in birds” Dutch Birding 28 (2): 79-89. This publication is the only one, that I am aware of, that summarizes terminology and definitions of almost all known color mutations occurring in birds. A must read by anybody who has even the slightest interest to try classifying color aberrations in the field and does not want to make a nonsensical mistakes especially with using incorrect terminology to describe her/his find. For example there are several names commonly used that are wrong by a definition: ‘partial albino’, ‘incomplete albino‘, etc.

August 5: I am assuming (based mainly on the wing molt stage: all outer primaries old, secondaries and inner primaries new) that all three birds are in their second year (hatched last year). So far I have a few opinions that are in agreement with my skimmers age assumption but I am still waiting for more responses and opinions.
Black Skimmer Head-shots.jpg
Black Skimmer Head-shots.jpg
Black Skimmer wings.jpg
Black Skimmer wings.jpg
BlackSkimmer tails.jpg
BlackSkimmer tails.jpg