内蒙古扎鲁特旗栗斑腹鹀的繁殖生态及子代性比

Breeding Ecology and Offspring Sex Ratio of Jankowski′s Bunting at Jarud Banner in Inner Mongolia

2012年和2013年两年的4至7月,在内蒙古通辽市扎鲁特旗对栗斑腹鹀(Emberiza jankowskii)的繁殖生态及子代性比进行了研究,发现栗斑腹鹀产首枚卵的时间为5月13日至6月12日,窝卵数平均为(5.1±0.6)枚(4～6枚,n=51),孵卵期平均为(11.5±0.7)d(10～12 d,n=19)。其中,2012年总计30巢,成功出飞13巢,繁殖成功率为43.3%;2013年总计30巢,成功出飞15巢,繁殖成功率为50.0%。栗斑腹鹀子代总体性比(雄性︰雌性)为(1.38±1.03)︰1(0.25︰1～4.00︰1,n=12),2012年和2013年的子代性比分别为(1.20±1.08)︰1(1.50︰1～4.00︰1,n=5)和(0.86±0.65)︰1(0.25︰1～2.00︰1,n=7),年际间栗斑腹鹀子代性比差异均不显著,P值分别为0.62(2012年)、0.44(2013年)与0.72(2012和2013年)。本研究对该地区栗斑腹鹀子代性比及提高栗斑腹鹀繁殖成功率和稳定其性比的措施进行了初步讨论。

We studied the breeding ecology and offspring sex ratio of Jankowski′s Bunting（Emberiza jankowskii） at Jarud Banner in Inner Mongolia during the breeding season of 2012 and 2013. Sex ratios of 12 nests with 59 offspring were identified by sequences amplified from CHD gene using the primer pair of sex1＇ and sex mix. Additionally, we used one-sample Kolmogorov-Smirnov test to judge if the sex ratios in 2012 and 2013 were normally distributed, and one-sample T test to calculate the average clutch size and female sex ratio. All of these were done via SPSS 21.0. In our study area, the earliest first-egg date varied from 13 th May to 12 th June; the average clutch size was 5.1 ± 0.6（4﹣6, n = 51）. The average hatching period was 11.5 ± 0.7 d（10﹣12 d, n = 19）, 13（43.3%） and 15（50%） nests fledged successfully in 2012 and 2013, respectively. Natural predators, abandon nests were the two main factors for nesting failures of Jankowski′s Bunting. The sequence length of Jankowski′s Bunting′s CHD gene was next to 170 bp, with part of the results showed in Fig. 1. According to the breeding sex ratio analyses from five nests in 2012 and seven nests in 2013, the breeding sex ratio was 1.20 ± 1.08（1.50﹣4.00, n = 5） in 2012 and 0.86 ± 0.65（0.25﹣2.00, n = 7） in 2013, the overall breeding sex ratio was 1.38 ± 1.03（0.25﹣4.00, n = 12）. In the one-sample Kolmogorov-Smirnov test, all the three ratios mentioned were normally distributed（P values were 0.62, 0.44 and 0.72）. Based on the K-S test′s result, the sex ratio were not differed significantly in one sample T test, with P values 0.14, 0.13 and 0.24 respectively. So, we suggest that the sex ratio of Jankowski′s Bunting offspring tends to be stable to 1︰1. Besides, we provided conservation suggestions on enhancing the breeding success of Jankowski′s Bunting.