Caro Samuel P, Balthazart Jacques, Thomas Donald W, Lacroix André, Chastel Olivier, Lambrechts Marcel M
Center for Cellular and Molecular Neurobiology, Research Group in Behavioural Neuroendocrinology, Univ. of Liège, 17 Place Delcour (Bât. L1), B-4020 Liège, Belgium.
Gen Comp Endocrinol. 2005 Jan 1;140(1):52-60. doi: 10.1016/j.ygcen.2004.09.016.
Analyses of the development of the reproductive system in seasonally breeding birds in the framework of long-term ecological studies are rare. Here, we present the first results of such a study in two Corsican populations of a European passerine bird, the blue tit (Parus caeruleus). The two study populations occupy different oak habitats and are separated by only 25 km. Despite their close proximity, they show a one-month difference in onset of egg laying, even after controlling for altitude. This micro-geographic difference in breeding date appears adaptive because both study populations raise chicks when food is most plentiful. In our study, males reached their maximum song activity during the egg-laying stage while maximal testosterone levels and testes sizes were reached 2-3 weeks before egg laying. The rate of development of the reproductive system in males was much faster in the earlier population, in spite of a similar onset of gonad development and song activity for the two study populations. No change in the volume of the song-control nuclei (HVC and RA) could be detected during the study period. Development of brain nuclei was completed 2-3 months before the beginning of intense sexual activity.
在长期生态学研究框架下，对季节性繁殖鸟类生殖系统发育的分析较为罕见。在此，我们展示了对欧洲雀形目鸟类蓝山雀（Parus caeruleus）在科西嘉岛的两个种群进行此类研究的首批结果。这两个研究种群占据不同的栎树栖息地，仅相隔25公里。尽管距离相近，但即使在控制海拔因素后，它们的产卵开始时间仍相差一个月。繁殖日期的这种微观地理差异似乎具有适应性，因为两个研究种群均在食物最为丰富时育雏。在我们的研究中，雄性在产卵阶段达到其最大鸣叫活动，而最大睾酮水平和睾丸大小在产卵前2至3周达到。尽管两个研究种群的性腺发育和鸣叫活动起始时间相似，但较早种群中雄性生殖系统的发育速度要快得多。在研究期间未检测到鸣叫控制核团（HVC和RA）体积的变化。脑核团的发育在强烈性活动开始前2至3个月完成。
