Larus fuscus intermedius Schiøler, 1922 · čajka tmavá severomorská · Lesser Black-backed Gull intermedius

Distribution

This card represents the Lesser Black-backed Gull subspecies Larus fuscus intermedius, breeding around the North Sea and south-western Scandinavia. It winters farther south in western Europe and Africa. In Slovakia it occurs on passage and in winter without a regular breeding population. Subspecies identification can be uncertain; insufficient evidence is best recorded as graellsii/intermedius or simply Lesser Black-backed Gull.

Habitat

Within its home range it uses coasts, islands and sometimes urban roofs. In Slovakia it visits large rivers, reservoirs, ponds and surrounding fields. It often rests in mixed large-gull flocks, allowing comparison of proportions and mantle tone under the same lighting.

Breeding

Nesting biology resembles that of the species. A vegetation nest is built on the ground or a suitable roof, normally holding three eggs. Both parents incubate and feed the young within the home range.

Food

It catches fish and invertebrates and takes carrion and assorted food scraps, feeding on water and in open terrestrial habitats.

Interesting fact

Adult intermedius usually has a darker mantle than graellsii, but shade alone does not provide a reliable boundary. A readable ring of known origin can strengthen the identification substantially.

Sources: BTO BirdFacts · English Wikipedia