HAITJEMA T (1982) Occurrence of the Caspian Tern Sterna caspia on the Steile Bank during autumn migration. LIMOSA 55 (2): 37-42.

Caspian Tern Hydroprogne caspia On the Steile Bank, a sandbank in the IJsselmeer off the coast of Friesland (fig. 1), a roost of Caspian Terns was discovered in 1977. In 1977-81 peak numbers varied between 11 and 20 (fig. 2). The first Caspian Terns arrive normally in the last week of July. It is suggested that two migration groups can be discerned (cf. fig. 3). Until the end of August mainly adults are seen (fig. 4). From late August onwards many family groups consisting of one or two parents with young (tab. 1), have been recorded. The last birds leave the Steile Bank in the third and fourth week of September. The seasonal pattern fits very well with the occurrence in the Swedish lakes area and the Camargue, France (fig. 5). It is assumed that the Caspian Terns of the Steile Bank forage on the surrounding IJsselmeer.

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