Caspian Gull is famous in having a rather white-ish head in its juvenile/1st winter plumage and this bird shows this quite clear. In most cases the paleness of the head stands out against the often more darker underparts and neck. Compare the pattern of the tertials, 2nd generation scapulars and (greater) coverts and the head structure to the Yellow-legged Gull below.

Yellow-legged Gulls usually show a pale head in juvenile/1st winter plumage although it is often more streaked than in Caspian, with the most streaking around the eye, forming a vague mask. The bill of this bird seems rather thin but the tip is blunt, contra Caspian Gull, which has a fine-tipped bill.

Moulting juvenile Yellow-legged Gull. Eemshaven, the Netherlands, 22 August 1999.

A contrasting individual with a very pale head and dark body. The firm body, large head, dark blunt-tipped bill and the pattern on its 2nd generation scapulars secure its identity. The flat head, also shown by the Herring Gull to the right, is caused by it being agitated whilst trying to find food in a frenzy.

Rarely Herring Gull can also show a pale head, like the bird shown here. The pale head is the more pronounced because of the rather dark coloration of the rest of its body. Pale-headed immatures among Herring Gulls often concern pale individuals, with equally pale underparts (see bottom picture). It may also be caused by abrasion during the winterseason. It is therefore more common in HG's from February onwards, again mostly concerning pale individuals. The rather short legs and wings as well as the pattern on its tertials and (rather few) moulted scapulars secure its identity as Herring Gull. Nevertheless it sticks out in the crowd. See the picture below where it stands among more typical HG's.

A pale-head combined with dark underparts, are pointers that 1st winter American Herring Gull L. smithsonianus could be involved but with this bird that is surely not the case. The patterns on its undertail-coverts as well as the side of its tail, both visible in the picture below, show too much white for this species.

Photographed as being a possible hybrid with Caspian Gull, but there isn't that much effidence supporting this. The structure of this bird and the pattern on the scapulars and wingcoverts are typical for HG. Still an unusual and marked bird with very pale head and underparts and one that takes a second look.