浙江德清野化放归朱鹮的繁殖行为

Reproductive Behavior of the Released Crested Ibis in Deqing,Zhejiang Province

2007年至今,我国在陕西宁陕、铜川和千阳,以及河南董寨和浙江德清初步建立了朱鹮(Nipponia nippon)野化放归种群。鸟类的繁殖行为是其生活史策略的重要组成部分,可以反映动物个体的营养状态、所处栖息地的质量,以及对栖息地的适应等。本文报道浙江德清朱鹮野化放归种群的繁殖行为,旨在了解其在我国南方的适应情况,为最终建立中国朱鹮南方种群提供科学支撑。本研究于2018年4和5月及2020年3至5月对浙江德清野化放归朱鹮的3个繁殖巢进行实时监测,记录孵卵期和育雏期繁殖行为,总记录时长为134 d,有效数据时长为2958 h。利用线性混合模型探究朱鹮衔巢材频率、孵卵期以及育雏期行为的影响因子,采用Spearman相关分析检验朱鹮翻卵频率与孵卵进程的关系,建立Logistic回归模型探究朱鹮亲鸟暖雏时长随雏鸟日龄的变化情况,并利用one-wayANOVA分析德清朱鹮与陕西洋县野生种群和其他野化放归种群的换巢频率差异。结果表明,德清朱鹮平均窝卵数3.7±0.3,孵化成功率90.9%,雏鸟出飞率100.0%;繁殖的不同时期、营巢条件和亲鸟性别均显著影响朱鹮的衔巢材频率;朱鹮的翻卵频率随孵卵进程显著下降;亲鸟的暖雏时长在雏鸟11日龄时下降率最大;育雏的不同时期对朱鹮的暖雏时长、换巢频率以及喂雏频率有极显著的影响;环境温度较高可能是导致德清朱鹮比洋县野生种群提前产卵的原因之一;较高的平均窝卵数与出飞成功率表明,朱鹮对我国南方的栖息地较为适应。鉴于本研究发现利用人工巢筐营巢的亲鸟花费更多时间补充巢材,表明人工巢筐的结构和大小有必要优化,建议在今后设计时加大筐壁仰角并减小深度、扩大外径,使人工巢筐更接近于自然巢的盘状结构,同时,应将巢筐底部设计成多孔透气、利于排水的结构,以适应我国长江中下游地区湿热多雨的气候。

[Objectives]Since 2007,five released populations of Crested Ibis(Nipponia nippon)have been established in Ningshan,Tongchuan and Qianyang in Shaanxi Province,as well as Dongzhai in Henan Province and Deqing in Zhejiang Province.The reproductive behavior is important to the life history strategies,and the study on the reproductive ecology of the reintroduced Crested Ibis in Deqing can also reflect the nutritional status and local habitat quality of Crested Ibis as well as their adaptation to southern China.This paper can provide scientific support for the establishment of Crested Ibis population in southern China.[Methods]The reproductive behavior of released Crested Ibis in Deqing,Zhejiang Province,was recorded by video cameras for a total of 134 d and valid data for 2958 h during the incubation and brooding stages in April-May 2018 and March-May 2020 in Deqing Xiazhu Lake National Wetland Park.The linear mixed models were used to explore the influence factors of the frequency of supplying nest-material and the reproductive behavior of Crested Ibis.We used Spearman correlation analysis to examine the relationship between the egg-turning frequency and the incubation process.The logistic regression model was used to explore the change of fledgling-warming duration of parent birds with the day age of fledglings.The one-way ANOVA was used to analyze the differences about nest-changing frequency between Deqing population and wild population as well as the other reintroduced populations.[Results]The results showed that the mean clutch size of the reintroduced Crested Ibis in Deqing was 3.7±0.3.The hatching success rate was 90.9%and the fledgling success rate was 100.0%(Table 1).Different breeding periods,nesting conditions and the gender of parent birds significantly affected the frequency of supplying nest-material of Crested Ibis(Table 2,3).The egg-turning frequency decreased significantly with the incubation process(Table 4,5).The largest decline of the duration of chick-warming was at 11 days of age(Fig.1).Different brooding periods had a significant impact on the duration of fledgling-warming and the frequency of feeding and nest-changing in the Crested Ibis(Table 6,7).[Conclusion]The higher environment temperature may be one of the reasons why the population of Deqing Crested Ibis lied eggs earlier than wild population in Yangxian County.The higher average clutch size and fledgling success rate may indicate that the Crested Ibis was adapted to the habitat of southern China.The Crested Ibis which used artificial nest-baskets spent more time supplying nest-material,indicating the necessity to improve the artificial nest-basket design in the future.We suggest to increase the open angle and reduce the depth of the nest-basket,and expand the outer diameter that close to the natural nests.At the same time,the bottom of the nest-basket should be designed as a porous and breathable structure that is conducive to drainage,in order to adapt to the humid and rainy climate in the middle and lower reaches of the Yangtze River in China.