Larus cachinnans
(last update:
Greg Neubauer
Marcin Przymencki
Albert de Jong
Mars Muusse
cachinnans plumages
From the Rarities Committee's files - Identification of Caspian Gull. Part 2: phenotypic variability and the field characteristics of hybrids, by Chris Gibbins, Grzegorz Neubauer and Brian Small, IN: BB 104/2011.
Fig. 2. Moult scores (mean and SE) from a sample of first-winter Caspian Gulls Larus cachinnans in southern Poland (n = 114).The score for each bird is the sum of values for moult in its median and greater coverts and tertials.
For coverts, scores are categorical:
0 = no moult,
1 = 1-3 new feathers,
2 = more than 3 feathers but less than a third of total,
3 = between a third and a half of all feathers, and
4 = more than half of all feathers in the group.
Tertial scores are simply the number of new feathers present. Values shown in the plot are the number of individuals scored in each month.
