Among the Carnivora, there is sparse evidence for any substantive fitness benefits of post reproductive lifespan (PRLS, survival after reproductive cessation, RC). Using the European badger (Meles meles) as a model species, we analyzed sex-specific cross-sectional endocrinological and morphological data to investigate: 1) age-dependent reproductive decline in sex-steroid levels versus prime reproductive age; 2) age-dependent declines in somatic condition and reproductive advertisement (from subcaudal scent gland secretion); 3) changes in reproductive success with age due to somatic and endocrinological decline; 4) occurrence of RC, PRLS, and post reproductive representation (PrR) in the population with reference to pre-pubescent hormone levels and evidenced by fewer cub assignments from pedigree. We provide strong evidence for a gradual, not abrupt, decline in sex-steroid levels with age, with both sexes following a concave (down) quadratic trend. For both sexes, the onset of decline in somatic condition commenced at the age of 3 years. In contrast, decline in reproductive hormones started at age ca. 5.5 years in females and 6 years in males, with similar rates of decline thereafter. Subcaudal gland secretion volume also decreased in both sexes, especially after age 5, suggesting less investment in reproductive advertisement. After age 3, fewer (surviving) females were assigned cubs. This coincided with the onset of somatic decline but came earlier than hormonal decline (5.5 years onwards). The decrease in offspring assignments commenced later in males at age 5-6 years; concomitant with onset of testosterone decline at 6 years. This suggests that, contrary to females, in males declining body condition does not preclude reproductive success (no 'restraint') in advance of hormonal senescence ('constraint'). There was evidence of female PRLS, with very old adults living up to 2.59 ± 1.29 years after RC; although in males this evidence was weaker. We discuss the implications of these findings for RC and PRLS in the context of adaptive and non-adaptive hypotheses. There was evidence of over 2 years of Post Reproductive Life Span in both sexes.

中文翻译：

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欧洲獾（Meles meles）的生殖和躯体衰老：来自终生性类固醇概况的证据

在食肉目中，很少有证据表明生殖后寿命（PRLS，生殖停止后的生存，RC）有任何实质性的健康益处。使用欧洲獾（Meles meles）作为模型物种，我们分析了性别特异性横断面内分泌学和形态学数据，以调查：1）与黄金生育年龄相比，性类固醇水平的年龄依赖性生殖下降；2) 躯体状况和生殖广告的年龄依赖性下降（来自尾下气味腺分泌）；3）由于体细胞和内分泌衰退导致的生殖成功率随年龄的变化；4) 参考青春期前激素水平，种群中 RC、PRLS 和生殖后表现 (PrR) 的发生，并由系谱中较少的幼崽分配证明。我们为渐进的、不是突然的，随着年龄的增长，性类固醇水平下降，两性都遵循凹（下）二次趋势。对于两性，躯体状况的下降开始于 3 岁。相比之下，生殖激素的下降始于大约年龄。女性为 5.5 岁，男性为 6 岁，此后下降速度相似。两性的尾下腺分泌量也减少，特别是在 5 岁以后，表明对生殖广告的投资较少。3 岁以后，分配给幼崽的（幸存的）雌性较少。这与体细胞衰退的开始相吻合，但早于荷尔蒙衰退（5.5 年以后）。雄性在 5-6 岁时开始减少后代分配；伴随 6 年睾酮开始下降。这表明，与女性相反，在雄性中，身体状况下降并不妨碍在荷尔蒙衰老（“约束”）之前的生殖成功（没有“约束”）。有女性 PRLS 的证据，RC 后非常年长的成年人活了 2.59 ± 1.29 年；尽管在男性中这种证据较弱。我们在适应性和非适应性假设的背景下讨论了这些发现对 RC 和 PRLS 的影响。有证据表明两性的生殖后寿命都超过 2 年。我们在适应性和非适应性假设的背景下讨论了这些发现对 RC 和 PRLS 的影响。有证据表明两性的生殖后寿命都超过 2 年。我们在适应性和非适应性假设的背景下讨论了这些发现对 RC 和 PRLS 的影响。有证据表明两性的生殖后寿命都超过 2 年。