Showing posts with label Larus canus heinei. Show all posts
Showing posts with label Larus canus heinei. Show all posts

Tuesday, 5 February 2013

Russian Common Gull (Larus canus heinei), 2cy, 16.1.2013, Svanemøllebugten, Copenhagen

It is the upper left individual. Note that it is taller, but also stronger and heavier than the average canus in direct comparison. Note the heavy breast and beer belly...


On January 16, 2013 I photographed this large heinei Common Gull in Copenhagen. Together with Kjeld Tommy Pedersen I was out feeding gulls and it was immediately striking mostly due to its long wings, large size and heavy structure compared to the nearby canus. Due to its long legs, pushed up breast, slender and elongated structure and long bill, there was almost a cachinnans jizz to it. It was obviously much taller and structurally different from all the canus.

Luckily, Kjeld caught and ringed the same bird a few days later on January 22, 2013 which allowed for the needed measures to confirm the identification. It had a total head length of 100.6 mm and the folded wing was 395 mm – thus clearly a heinei on wing length (max wing in canus 390mm). According to Kjeld one should actually add 7-10 mm to the wing measure because it is a 2cy individual and they grow even longer with age. It was really a long winged and large individual.

It was ringed with metal AC 5558 and yellow colour ring with the inscription K9J.

It is the left of the two individuals seen from behind. Note the thicker and longer legs.

Note the densly dark-patterned hindneck, creating solid dark necklace.

Retarded moult in February with massive presence of juvenile feathers in upperparts is a classic heinei feature; however, it can also occure in late breeding canus from northern populations.




The bill is heavier and more parallel-edged relative to canus in direct comparison.


It was a large bird...

Note the relatively broad tail band and how the black on especially the outer feathers creates bayonets. On some Common Gulls wintering in Japan, the black tail band is wide enough to reach the edge of the uppertail coverts. Photo: Kjeld Tommy Pedersen.

Saturday, 1 August 2009

Russian Common Gull (Larus canus heinei), ad, 8.1.2009, Universitetsparken, Aarhus

Fuglen på billederne blev fundet og aflæst af undertegnede den 8. januar 2009 og den blev indledningsvis bestemt til en mulig Russisk Stormmåge (ssp. heinei) ud fra proportioner og oversidens farve. Men en sådan feltbestemmelse er uforsigtig og utilrådelig. Men fuglen var heldigvis projektmærket og udgjorde derfor en unik mulighed for at teste feltbestemmelsens validitet.

Efter fuglen på behørig vis var fotodokumenteret og feltnoter nedfældet, kontaktede jeg Kjeld Tommy Pedersen fra Zoologisk Museum i København. Jeg var bekendt med at han hvert år farvemærker Hættemåger og Stormmåger i Århus.

Kjeld bekræftede bestemmelsen alene ud fra de biometriske målinger han havde fortaget under mærkningen den 29. november 2008.

Totallængde af hoved og næb (THL): 92.8 mm
Totallængde af næb: 38.0 mm
Vingelængde: 386,0 mm

Feltbestemmelsen blev fortaget under sammenligning med talrige alderssvarende ssp. canus. Bestemmelsen bygger på at fuglen i felten virkede relativt mørkfarvet på ryggen, den havde lange vinger med p5 tydeligt eksponeret bag længste tertiær foruden fuglen virkede påfaldende langstrakt, slank og storhovedet.



Russisk Stormmåge