Foraging 'enrichment' as treatment for pterotillomania

Source: Journal of Applied Animal Behaviour Science, 2008, vol 111, issue 1-2
This study was performed to determine whether foraging 'enrichment' reduces self-directed psychogenic feather picking (pterotillomania) in parrots. A positive correlation between increased foraging time and improvement of feather score was hypothesised.
Eighteen pterotillomanic African grey parrots (Psittacus erithacus) were randomly assigned to experimental and control groups in a crossover design for two 1-month-periods. The experimental group received food in pipe feeders, while the controls received food in a bowl in the presence of two empty pipe feeders.
The 10-point plumage scoring system from Meehan was used as an indirect measurement of feather picking behaviour (better plumage results in higher score). Scoring took place before the study; after 4 weeks, just before the crossover; and 4 weeks after the crossover. Foraging time was calculated with a time-lapse recorder.
A pipe feeder significantly increased foraging time and feather score. The logistic model of the influence of foraging time on improvement of feather score was significant (Chi-square 7.1; d.f. = 1; P = 0.0076). Each hour extra spent on foraging multiplies the odds of improvement of feather score with a factor 2.9 (95% CI 1.2–7.0).
The results suggest that the redirected foraging hypothesis might be an explanation for pterotillomania in African grey parrots and provide an effective treatment strategy for this common behavioural disorder. The findings may have implications for the treatment of trichotillomania in humans.

Title: Foraging ‘enrichment’ as treatment for pterotillomania

Authors: Johannes T. Lumeij and Caroline J. Hommers