Understanding reproductive physiology of a species is important to assess their potential to respond to environmental variation and perturbation of their social system during the mating or pre-mating seasons. We report 175 parturition dates from wild Eurasian lynx ( Lynx lynx ) in Scandinavia. Most lynx birth dates were highly synchronised around a mean of 30th May (SD = 9 days) with 173 of the 175 births ranging from May 2nd to June 30th. We detected two very late births on July 29th and August 15th in the absence of any indication that the females had given birth and lost a litter earlier in the year. We propose that these represent evidence of a second oestrus which is highly unusual in lynx because of their unique reproductive physiology. The rarity of these late season births has implications for lynx demography and social organisation.

中文翻译：

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野生欧亚猞猁的分娩日期：第二次发情的证据？

了解物种的生殖生理学对于评估它们在交配或交配前季节对环境变化和社会系统扰动做出反应的潜力非常重要。我们报告了斯堪的纳维亚野生欧亚猞猁（猞猁猞猁）的 175 个分娩日期。大多数山猫的出生日期在 5 月 30 日（SD = 9 天）的平均值附近高度同步，175 次出生中有 173 次出生在 5 月 2 日至 6 月 30 日之间。我们在 7 月 29 日和 8 月 15 日检测到两次非常晚的分娩，但没有任何迹象表明雌性在今年早些时候分娩并失去了一窝。我们认为这些代表了第二次发情的证据，由于猞猁独特的生殖生理学，这在猞猁中非常不寻常。这些晚季出生的稀有性对猞猁人口统计学和社会组织有影响。