Feather damaging behaviour in parrots: stereotypy or impulse control disorder?

Abstract

Abnormal repetitive behaviours are a certain class of behaviours that can be expressed by individuals kept in a restricted environment. Feather damaging behaviour in parrots can be classified as an abnormal repetitive behaviour. However, due to a lack of knowledge, further sub-classification is not possible yet. The two subclasses, stereotypic behaviours and impulse control disorders, are controlled by different structures in the brain. In the mammalian brain, the basal ganglia are mostly responsible for motor control, while structures belonging to the limbic system (i.e. the prefrontal cortex and amygdala) control impulsive behaviours. In the avian brain, comparable structures are involved. Changes in the motor control and impulse control system are found in relation to stereotypic behaviours and impulse control disorders respectively. In addition to using neurological measurements, multiple behavioural tests can be used to score either stereotypic or impulsive behaviour. A combination of behavioural and neurological tests is suggested to determine correct classification of feather damaging behaviour to either one of the abnormal repetitive behaviour subclasses.