Larus Agentatus Argenteus

Larus Agentatus Argenteus

Larus Agentatus Argentatus

Larus Agentatus Argentatus



Larus Agentatus Argentatus




Argentatus and Argenteus 2nd winter (3rd calender year) herring gulls

The photos above are of 2 herring gulls that are of the same age but are very different in appearance. I took them on saturday 23rd feb at Prescot reservoirs.The top 2 are of the british sub species argenteus and the bottom 3 are of the northern european sub species argentatus. The main difference between them is that the mantle and scapulars are mostly an adult-like pale grey on the argenteus at this age giving it a saddled appearance but the argentatus looks almost like a first winter as its mantle and scapulars have moulted through with anchor markings on them. The pale iris and rounded primary tips age it as a second winter. Argenteus also shows a broad dark tail band and less streaking on the head and neck. The wing coverts and tertials are very pale and have a contrasting pattern on the argentatus. The argentatus also looks a bigger bird, more fierce looking, longer legged and more attenuated at the rear with a longer primary projection. Also note the tail pattern on the argentatus is similar to 1st winter great black backed gull. This is typical of these gulls although this argentatus is towards the paler end of the scale but there is a lot of individual variation. These are my observations but feel free to comment on the above if you have not already fallen asleep! Always willing to learn.