Finnish Focus on... Juvenile Caspian Gull
The season of juvenile Caspian Gull is upon us and so it's time to refresh that mental search image. Caspian Gull (right) - Juvenile - August 18 2018. Compared with Herring Gull of the same age (left) juvenile Caspian gull are an entirely darker and more uniform beast above, whilst being a cleaner whiter creature on the head and underparts. Mantle, scapular, wing coverts and tertials tend towards a plain, matte greyish-brown colouration (though some are warmer), with a simple, even, thin and unnotched white fringe. What notching there is, tends to be small indentations, almost like barring, rather than the large triangular sawtooth or piano key patterns of Herring Gull. The tertials usually have a classic "thumbnail" pattern, with a plain narrow white fringe around the tip, most commonly extending just a short distance up the sides, the rest of the feather fringe being plain. As the autumn progresses on, the center of the feather tip becomes paler, broadening this fringe.