Wildlife management factors and their effects on hair cortisol levels and glucocorticoid and mineralocorticoid levels in the hippocampus of fallow deer (Dama dama) as chronic stress and welfare indicators

Abstract

A positive state of welfare for all animals including wild animals is becoming a more important field of interest for people. Welfare can be seen as a dynamic concept. According to this concept an animal has to be able to adapt itself to its surrounding and reach a state that it perceives as positive in order to be in a positive welfare state. Finding an adequate way to measure welfare in animals can be helpful in discussions concerning the human role in wildlife welfare. An adequate way to measure welfare might be by measuring chronic stress indicators. In this study we measured chronic stress in fallow deer by measuring hair cortisol levels and glucocorticoid receptor and mineralocorticoid receptor levels in the hippocampus. These results were combined with information on park management factors to determine which park management factors contributed to chronic stress and therefore impaired welfare. Fallow deer from eleven different parks in the UK and from the Amsterdamse Waterleidingduinen in the Netherlands have been used in this study. Population density has been identified as an important factor with an effect on chronic stress in fallow deer. These findings are more pronounced considering hair cortisol levels than glucocorticoid receptor levels. Based on these findings we may carefully suggest that management factors in nature parks should consider population density to reduce chronic stress and thereby improving the welfare status of fallow deer.