Hormonal response of Arctic fox females to short- and long-term stress

The aim of this study was to determine the extent of the hormonal response of Arctic fox females exposed to two types of stress: short-term and long-term, combined with adaptation to new environmental conditions. Short-term stress (20 min) was investigated in 34 females on farm A in the Wielkopolska province. The testing procedure involved capturing of the animals, their immobilisation, phenotype evaluation, and placing in target cages. Blood for laboratory examinations was collected from the vena cephalica antebrachii three times: on the day of the test, directly after the procedure and after three days. Long-term stress (8 h), combined with adaptation to new environmental conditions, was examined in 30 females which were purchased from a farm in the Lodzkie province (farm B). The testing procedure involved selection and capture of the animals, immobilisation and transfer from the pavilion, blood collection and placing of animals in a transport cage. Transport of the animals to the target farm (farm A) lasted approximately 8 h. Blood was collected five times in total, i.e. before transport (on farm B), after the transport to farm A, and then after three days, whereas the last two samplings were conducted at a 5- and 15-day interval from the third blood collection. The control group consisted of 20 randomly selected females from farm A. Blood from these animals was collected twice - at the beginning and at the end of the experiment. Changes in hormone concentrations (cortisol and testosterone) were adopted as a measure of sensitivity to a stressor. Blood hormones were analysed using a radio-immunological method. The course of stress reaction was affected by exposure time and stressor intensity, and significant changes in cortisol (P ≤ 0.01) and testosterone (P ≤ 0.05) concentrations were noted among individuals subjected to both short-term and long-term stress. Increased cortisol concentrations were maintained for a longer time in the group of Arctic fox females exposed to a long-term stress. In conclusion, the course of a stress reaction is affected by the duration of exposure and intensity of the stressor, and the strong stress reaction to zootechnical treatments and transport confirms the lack of complete domestication of this species.