Intra- and inter-observer reliability of two different feather scoring methods in Grey parrots (Psittacus erithacus erithacus)

Abstract

Feather damaging behavior is one of the most challenging behavioral problems in captive parrots. Several therapeutic options have been proposed and to evaluate the effectiveness of these treatments a reliable and valid way of evaluating feather damaging behavior is needed. The aim of this study was to examine the intra- and inter-observer reliability of the feather scoring method by Meehan and the feather scoring method by Van Zeeland. Photographs of 15 Grey parrots were selected. For the intra-observer reliability 10 parrots were assessed twice by 5 students and 6 specialists. For the inter-observer reliability 10 students and 7 specialists have assessed the photographs of all the 15 parrots. Intraclass correlation coefficients (ICC[2,1] and ICC[2,k]) with 95% confidence intervals, standard error of measurement and the minimum difference to be considered real were calculated. An independent-samples t-test was conducted to compare ICC [2,1] and [2,k] values for the intra- and inter-observer reliability of both scoring methods. The intra- and inter-observer reliability was very high for both scoring methods. The feather scoring method by Van Zeeland showed a significantly higher ICC[2,1] and ICC[2,k] for the intra-observer reliability and a significantly higher ICC[2,1] for the inter-observer reliability. This study demonstrated that the feather scoring method by Van Zeeland showed a significantly higher reliability than the feather scoring method by Meehan.