黑犀牛(犀牛)(Dicerosbicornis)濒临灭绝,偷猎是对该物种生存的几种威胁之一。许多国家的储备,包括纳米比亚,南非,津巴布韦,现在,为了减少偷猎,他们的犀牛脱角。纳米比亚环境部收集的历史数据,林业,以及旅游和拯救犀牛信托基金被用来调查去猎犬是否对首次繁殖年龄(AFR)有影响,产卵间隔(ICI),出生性别比,小牛生存,死因,和寿命。这些是在黑犀牛的四个纳米比亚亚群(以下称为“种群”)中进行评估的(表示为A,B,C,和D)经历了不同程度的去角。在脱角和有角个体之间的任何变量中都没有发现显着差异。人群是AFR(LRT=7.433,p=0.024)和ICI(LRT=13.281,p=0.004)的显著预测因子,尽管配对比较仅发现A和B群体存在显着差异(AFR:z=-2.736,p=0.017,ICI:z=-3.705,p=0.001)。此外,D人口中出生的男性人数明显高于女性(p=0.021,CI=0.544,0.960)。所有个人死亡的主要原因是偷猎,尽管去角个体和有角个体之间偷猎的犀牛比例没有显着差异(X2=0.638,p=0.424,n=265)。没有证据表明去角对AFR有任何影响,ICI,出生性别比,小牛生存,或者黑犀牛的寿命,令人放心的是,在该物种中继续使用去角化作为一种反偷猎技术。
The black rhinoceros (rhino) (Diceros bicornis) is critically endangered, with poaching being one of several threats to the species\' survival. Many reserves across several countries, including Namibia, South Africa, and Zimbabwe, now dehorn their rhinos in an attempt to reduce poaching. Historical data collected by the Namibian Ministry of Environment, Forestry, and Tourism and Save the Rhino Trust were used to investigate whether dehorning has an effect on age at first reproduction (AFR), inter-calving interval (ICI), birth sex ratios, calf survival, cause of death, and lifespan. These were assessed in four Namibian sub-populations (hereafter referred to as \'populations\') of black rhino (denoted A, B, C, and D) which have undergone varying levels of dehorning. No significant difference was found in any of the variables between dehorned and horned individuals. Population was a significant predictor of AFR (LRT = 7.433, p = 0.024) and ICI (LRT = 13.281, p = 0.004), although pairwise comparisons only found populations A and B to be significantly different (AFR: z = -2.736, p = 0.017, ICI: z = -3.705, p = 0.001). Additionally, a significantly higher number of males than females were born in population D (p = 0.021, CI = 0.544, 0.960). The main cause of death across all individuals was poaching, although there was no significant difference in the proportion of rhinos poached between dehorned and horned individuals (X 2 = 0.638, p = 0.424, n = 265). No evidence was found to suggest that dehorning has any effect on AFR, ICI, birth sex ratios, calf survival, or lifespan in the black rhino, which is reassuring in the continued use of dehorning as an anti-poaching technique in this species.