This study aimed to contribute to the conservation of red pandas by improving the understanding of their oestrus cycle through examining urinary hormone changes during their breeding season. To minimize stress associated with blood sample collection, we used urine samples Sex hormone levels were measured over six months in pregnant and nonpregnant red pandas, to help understand changes in oestrogen concentrations during oestrus, post-mating progesterone concentrations and differences in ceruloplasmin concentrations. The results of the study revealed that female red pandas are polyoestrous, with a second oestrogen peak after mating. Progesterone changed in a cascading fashion, peaking and then gradually declining. Successfully mated females showed higher levels of progesterone than unsuccessfully mated females, which had no peak in progesterone after mating. Ceruloplasmin was measured to confirm pregnancy, but its value as a pregnancy diagnostic factor was not confirmed. These results provide significant insights into the reproductive physiology of red pandas and lay the foundation for additional research towards improving the management and breeding strategies for this threatened species.
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