Characteristics of Mediterranean/ Dark Atlantic Intersection Forms

A map showing the approximate boundaries of the Dark, Cantabrican and west Portugal/north-west Spain cline is shown in Figure 3 . The darkness of the mantles at Faro and Asilah, only 250 and 50 km respectively from Tanger, shows the range of the Dark Atlantic Yellow-legged Gull form extends very close to the entrance to the Mediterranean. On the boundaries, possible intermediate populations may occur between Dark Atlantic and Mediterranean Yellow-legged Gulls in the Huelva/ Cádiz/ Tanger/ Gibraltar/ Malaga area.

Preliminary findings:

Tanger

Gibraltar

Nerja

Cádiz, Huelva: the Yellow-legged Gulls breeding in these areas are thought to originate from the Mediterranean (Ruiz & Solis, 1984) but no detailed field descriptions are available.

 © Copyright Nick Rossiter 2000-2001.