The relationship between thermophysiology, endocrinology and behaviour in female giant pandas

The breeding of giant pandas is attracting great attention as it concerns population stability. Due to the lag in hormone testing, it is impossible to assess the oestrus state of female giant pandas efficiently and concisely via hormone monitoring accompanied by separate empirical behaviour. Here, 6 female giant pandas were selected to monitor the oestrus period. Infrared thermography was utilized to measure eye temperature. Simultaneously, urinary hormone levels and behaviours were recorded daily. Subjects in oestrus exhibited significant differences in eye temperature, hormone levels and behaviours compared with those in their in non-oestrus. Specifically, the average eye temperature in oestrus was significantly higher than that in non-oestrus. The eye temperature of giant pandas began to rise from the pre-oestrus phase, reached a maximum in the oestrus peak phase and began to decline after mating, but was still higher than the average temperature in non-oestrus. There were significant correlations among eye temperature, hormone levels and behaviours. The main physiological changes in female giant pandas in thermophysiology, endocrinology and behaviour can be used to assess the shift in oestrus. Our study breaches the limitations of traditional methods and provides a robust and reliable method to judge the oestrus of captive female giant pandas.