Figure 1.

Sampling locations of gulls in Iceland. Numbers refer to locations listed in table 1. Samples included in population comparisons per location are 1 (a3w), 2 (h1w, h2 and h3), 3 (h1w), 4 (a1, a2 and a3e) and 5 and 6 (a1 and h1e). The main nesting areas of L. hyperboreus are in northwestern Iceland (2 and 3), whereas L. argentatus is mainly nesting in eastern Iceland (4–6).