"'t Zal wel zijn! Wetenschap en zo!"

"Still with black spots in the tail!"

"Looking very adult-like already, except for dark marks on primary coverts (especially on underwing)."

"An individual that already looks adult in all respects."

"An individual that already looks adult in all respects."

"An individual that already looks adult in all respects."

"Note small whitish mirror on (old) P10."

"WIth 1st (to 2nd) cycle Yellow-legged Gull to the left of it."

"A pale individual."

"with nesting material"

"With 1st to 2nd cycle Yellow-legged Gull to the right."

"With male (blue HYA.F) to the left."

"A rather odd, dark bird with fairly dark grey new inner primaries and primary coverts."

"Now in its 10th cycle, this bird still has black spots on the tail feathers!"

"Now in its 10th cycle, this bird still has black spots on the tail feathers!"