The quality of the territory has been suggested to affect breeding success and adult survival in Magpies P. pica. Magpie territories were arbitrarily divided into 3 groups: I (territories occupied for a single year), II (territories occupied for 2-7 yr) and III (territories occupied for 8-10 yr during the period 1972-1981). Preferred territories (class III) were composed of preferred feeding habitats. Tree-top sitting took place in high quality territories more often than in low quality ones. Territory intrusions were common in high quality territories. Ceremonial gatherings also occurred most frequently in these territories. Carrion crows Corvus corone cornix, being common nest predators, occurred habitually in medium quality territories. Nests were placed higher, although at the same relative height, in high quality territories compared to low quality ones. Nests in class I territories were initiated later than those in class II-III territories. Nearly all nests in high quality territories were placed near buildings. Nest failure was most common in low quality territories. Replacement nests were built most often in high quality territories. In those territories magpies spent less time feeding, pecked at a lower and more uniform rate when feeding and moved at a higher speed when feeding compared to low territory quality birds. Magpies flow continuously from low quality to high quality territories as their experience allows them to refill empty spaces arising from death or divorce in other Magpie pairs.