Habitat fragmentation has negative consequences on threatened and endangered species by creating isolated populations. The Texas horned lizard (Phrynosoma cornutum) is experiencing population declines and localized extirpations throughout its range and has been classified as a species of greatest conservation need in Oklahoma, USA. Younger age classes have been poorly studied but may be vital to the stability of remaining populations. To address gaps in knowledge concerning subadult (hatchling and juvenile) morphometrics, survivorship, and home range sizes, we studied 2 cohorts of subadults, for 2 years each, covering their hatching and juvenile years (2016–2019). We used a combination of radio-telemetry and novel harmonic radar methodology to study a closed population of Texas horned lizards in 15 ha of native grassland at Tinker Air Force Base, Oklahoma. Population abundance for adults and juveniles was estimated as 56.5 ± 5.5 lizards and density as 7.96 lizards/ha. Our lowest estimates of survival indicated an average survival probability for the hatchling life stage of 0.285 (95% CI = 0.15–0.44), which is lower than for adults on the site. Average home range size increased from hatchling to adult life stages. Our results will have an immediate effect on the planning and assessment of ongoing headstart and management programs for Texas horned lizards. © 2021 The Authors. The Journal of Wildlife Management published by Wiley Periodicals LLC on behalf of The Wildlife Society.

中文翻译：

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德克萨斯角蜥城市种群的生存和空间模式

栖息地破碎化造成孤立的种群，对受威胁和濒危物种产生负面影响。德克萨斯角蜥（Phrynosoma cornutum) 在其整个范围内正在经历人口下降和局部灭绝，并已被列为美国俄克拉荷马州最需要保护的物种。对年轻年龄段的研究很少，但可能对剩余人口的稳定性至关重要。为了解决关于亚成体（幼体和幼体）形态测量学、存活率和家庭范围大小的知识差距，我们研究了 2 个亚成体队列，每组 2 年，涵盖它们的孵化和幼体年（2016-2019）。我们结合使用无线电遥测和新颖的谐波雷达方法来研究俄克拉荷马州廷克空军基地 15 公顷原生草原中的德克萨斯角蜥的封闭种群。成虫和幼虫的种群数量估计为 56.5 ± 5.5 只蜥蜴，密度为 7.96 只蜥蜴/公顷。我们对存活率的最低估计表明，幼体生命阶段的平均存活概率为 0.285（95% CI = 0.15–0.44），低于现场成人的存活概率。平均家庭范围大小从孵化到成年生命阶段增加。我们的结果将对德克萨斯角蜥蜴正在进行的领先和管理计划的规划和评估产生直接影响。© 2021 作者。这由 Wiley Periodicals LLC 代表野生动物协会出版的《野生动物管理杂志》。