Our ISF-funded project on bird stopover ecology combines measurements of bird movement using the ATLAS system which covers the area of the Hula Valley in north-eastern Israel, bird behaviour and body mass in the field. The study species in the Red-backed shrike (Lanius collurio), an abundant autumn migrant passerine in Israel. Individuals of this species are weighted during their stopover period using field deployed scales and their interactions with competitors are recorded by observers. The study asks what affects local movements during foraging and the switching of stopover sites during a stopover period that may last up to several weeks. In addition, it explores the factors affecting the departure of the birds to continue their migration, primarily the birds’ fat deposition rate and the level of body fat at the time of departure for migration.