不同释放策略对朱鹮再引入种群存活率和繁殖成功率的影响

Effect of Different Release Strategies on Population Survival and Reproductive Success in Reintroduced Populations of the Crested Ibis

物种再引入目前已成为一种拯救、恢复珍稀濒危物种的重要手段。研究释放后的个体存活和繁殖成功率可以更好地优化释放策略,指导不同释放地释放后的管理。利用方差分析比较了陕西省朱鹮(Nipponia nippon)再引入三个释放地宁陕、铜川和千阳首次释放个体的平均年龄,结合释放后的监测数据,比较了释放后个体存活率和繁殖成功率。利用广义线性混合模型,分析放归个体年龄、性别、个体来源和野化训练时长对释放后6个月个体存活率的影响。结果表明,三个释放地首次释放个体的平均年龄差异显著(F=40.35,df=2,P<0.001),宁陕首次释放个体的平均年龄较大,为(6.1±1.9)岁。铜川释放后个体存活率(65.6%)最高,千阳次之(61.5%);三个释放地释放后的前3年繁殖成功率差异较大(ANOVA,df=2,P<0.05),铜川繁殖成功率最高,为57.7%±34.3%(n=14,其中2014年繁殖2巢,2015年繁殖6巢,2016年繁殖6巢),宁陕次之,为52.3%±43.3%(n=14)。释放个体年龄与释放后个体存活率显著负相关(β=﹣0.21,95%置信区间CI为﹣0.45~﹣0.04,P<0.05),而性别、个体来源和野化训练时长对释放后个体存活率影响不显著。基于三个释放地释放后个体存活率和繁殖成功率的差异,我们建议针对释放地的特定环境,可根据种源的年龄结构及个体的遗传组成来选择释放群体;可将不同种源的个体在释放地混合圈养,开展适当的野化训练后再进行释放;秋季可能是朱鹮的最佳释放时间。

[Objectives]Reintroduction programs have emerged as an important tool for saving and restoring rare and endangered species.Studies on individual survival and reproductive success after release can better optimize release strategies and guide post-release management in different release sites.[Methods]Analysis of variance(ANOVA)was used to test the average age of individuals first released in different release sites of reintroduced Crested Ibis(Nipponia nippon)in Shaanxi Province,and to compare the survival rate and reproductive success after release combined with the monitoring data after release.Generalized linear mixed model was used to analyze the effects of age,gender,individual source and duration of rewilding training on post-release survival probability at 6 months after release.[Results]The average age of first released individuals in the three release sites was significantly different(F=40.35,df=2,P<0.001).The average age of first released individuals in Ningshan was the largest,which was 6.1±1.9 years old(Table 1).Post-release survival probability of individual in Tongchuan was the highest(65.6%),and post-release survival probability of individual in Qianyang was the second(61.5%).There were significant differences in reproductive success in the first 3 years after release in different release sites(ANOVA,df=2,P<0.05),and the highest reproductive success was 57.7%±34.3%(n=14,two,six and six nests were bred in 2014,2015 and 2016,respectively)in Tongchuan,followed by 52.3%±43.3%(n=14)in Ningshan(Table 3).Individual age was significantly negatively correlated with post-release survival probability(β=-0.21,95%confidence interval,CI:-0.45 to -0.04,P<0.05,Table 2).However,gender,individual source and duration of rewilding training had no significant effect on survival rate after release.[Conclusions]Based on the differences in survival and reproductive success among the three release sites,we suggest that the release group can be selected according to the age structure of the source population and the genetic composition of the individuals in the specific environment of the release sites.Individuals from different source population can be mixed in captivity at the release site,and then released after appropriate rewilding training.Furthermore,the results showed that autumn may be the best release time of crested ibis.