Effects of whole-year nest boxes on cortisol, circulating leucocytes, exploration and agonistic behaviour in silver foxes.

An experiment was carried out for a period of 2 years, using 50 silver fox vixens kept in cages with nest boxes, and 50 vixens kept in barren wire cages without any sort of equipment. At the end of the experiment, the animals living with access to nest boxes had lower base levels of cortisol and eosinophils, and higher base levels of lymphocytes. They also were less fearful towards humans and more active/ explorative in an open field test. It was concluded that these animals were less stressed than those living without nest boxes, a result that could have practical implications for the welfare of foxes during everyday life at the farm.