Aiming to improve our reproductive knowledge of large birds of prey, behavioral data and fecal steroids were assessed in captive pairs of Harpy eagles, a keystone species that is monogamous and resides in the Neotropics year-round. Adult individuals exhibited different reproductive outcomes and a breeding season extending beyond summer solstice (5-9 months) suggests that harpy eagles may not be absolutely photorefractory. Comparisons among breeding stages in males revealed that mean androgen levels in courtship were higher than in copulation and incubation, but no differences were detected in fecal progestagens or estrogens. Females had higher mean estrogen concentrations in courtship and copulation, whereas mean progestagen levels peaked during egg laying. Mean androgen concentrations were not significantly different among breeding stages in females. Assessment of six egg-lay cycles from three females demonstrated that fecal estrogens peaked predominantly between 31 and 18 days before oviposition (-31 to -18 days), and then remained low until 45 days after laying the first egg (+45 days). In contrast, fecal progestagens raised mostly between -20 and +1 day, lowering to baseline concentrations by +3 days. To our knowledge, this is the first study to describe in detail endocrine and behavioral data regarding reproduction in tropical eagles, which may serve in the future as a reference to developing breeding programs.

中文翻译：

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哈比鹰 (Harpia harpyja) 的粪便性类固醇和生殖行为

为了提高我们对大型猛禽的生殖知识，对圈养的哈比鹰对行为数据和粪便类固醇进行了评估，这是一种一夫一妻制的关键物种，全年居住在新热带地区。成年个体表现出不同的繁殖结果，并且繁殖季节超过夏至（5-9 个月）表明角雕可能不是绝对耐光的。雄性繁殖阶段之间的比较表明，求偶期间的平均雄激素水平高于交配和孵化阶段，但在粪便孕激素或雌激素中未检测到差异。雌性在求偶和交配时平均雌激素浓度较高，而平均孕激素水平在产卵期间达到峰值。雌性的平均雄激素浓度在繁殖阶段之间没有显着差异。对三只雌性的六个产卵周期的评估表明，粪便雌激素主要在产卵前 31 至 18 天（-31 至 -18 天）达到峰值，然后在产下第一个卵后 45 天（+45 天）保持低水平。相比之下，粪便孕激素主要在 -20 至 +1 天之间升高，降低至基线浓度 +3 天。据我们所知，这是第一项详细描述热带鹰繁殖的内分泌和行为数据的研究，这些数据可能在未来作为制定育种计划的参考。然后在产下第一个鸡蛋后的 45 天（+45 天）保持低水平。相比之下，粪便孕激素主要在 -20 至 +1 天之间升高，降低至基线浓度 +3 天。据我们所知，这是第一项详细描述热带鹰繁殖的内分泌和行为数据的研究，这些数据可能在未来作为制定育种计划的参考。然后在产下第一个鸡蛋后的 45 天（+45 天）保持低水平。相比之下，粪便孕激素主要在 -20 至 +1 天之间升高，降低至基线浓度 +3 天。据我们所知，这是第一项详细描述热带鹰繁殖的内分泌和行为数据的研究，这些数据可能在未来作为制定育种计划的参考。