Abstract Context Wildlife biologists accumulate large quantities of images from remote cameras, which can be time- and cost-prohibitive to archive and analyse. Remote-camera projects would benefit from not setting cameras longer than needed and not analysing more images than needed; however, there is a lack of information about optimal deployment time required for remote-camera surveys to estimate ungulate abundance. Aims The objective was to estimate abundance of adult females in a population of Rocky Mountain bighorn sheep (Ovis canadensis canadensis) in Utah, USA, from 2012 to 2014, and determine whether this type of study can be conducted more efficiently. Because females are the most important cohort for population growth, remote cameras were set at three water sources and mark–resight models in Program MARK were used. Methods We compared estimated abundance of collared and uncollared females by number of days cameras were set using 31 replicated abundance estimates from each year starting 1 July. Each replicated estimate used a different number of days and photographs from a 62-day sampling period (1 July to 31 August). Key results Abundance estimates ranged from 44 to 98 animals. Precise estimates of abundance, however, were obtained with only 12 days of sampling in each year. By analysing only 12 days of images rather than 62 days in all years, the estimated mean of 58 adult females would have changed by only 7 individuals (±4 individuals, range = 3–10 animals), the s.e. would have increased by a mean of only 4 individuals (±1.6, range = 2.0–5.2 individuals) and a mean of only 18% (±10.5%, range = 8–29%) of images would have been analysed. Across the study, analysis of >23 000 (>80%) images could have been avoided, saving time and money. Conclusions The results indicate that an asymptotic relationship exists between estimated abundance of female bighorn sheep and remote-camera deployment time. Implications The mark–resight methods used in the present study would work for other ungulates in which individuals are radio collared or marked using remote cameras set at water sources, trail crossings or mineral licks. These findings can help researchers reduce cost of setting, servicing, archiving and analysing photographs from remote cameras for ungulate population monitoring.

中文翻译：

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优化远程摄像机的部署时间以估计雌性大角羊的丰度

摘要上下文野生动物生物学家从远程摄像机中积累了大量图像，存档和分析的时间和成本都非常高。远程摄像机项目将受益于不设置超过需要的摄像机和不分析超过需要的图像；然而，缺乏关于远程摄像机调查估计有蹄类动物数量所需的最佳部署时间的信息。目的 目的是估计 2012 年至 2014 年美国犹他州落基山大角羊 (Ovis canadensis canadensis) 成年雌性的丰度，并确定是否可以更有效地进行此类研究。由于女性是人口增长最重要的群体，因此在三个水源处设置了远程摄像机，并使用了 Program MARK 中的标记-观察模型。方法 我们使用从 7 月 1 日开始的每年 31 次重复的丰度估计值，通过设置相机的天数来比较有领和无领女性的估计丰度。每个重复估计使用了 62 天采样期（7 月 1 日至 8 月 31 日）的不同天数和照片。主要结果 丰度估计范围为 44 至 98 只动物。然而，每年仅通过 12 天的采样就获得了对丰度的精确估计。通过仅分析 12 天的图像而不是所有年份的 62 天，58 只成年雌性的估计平均值将仅改变 7 个个体（±4 个个体，范围 = 3-10 只动物），se 将增加一个平均值只有 4 个个体（±1.6，范围 = 2.0-5.2 个个体）和平均只有 18%（±10.5%，范围 = 8-29%）的图像会被分析。在整个研究中，本来可以避免对 >23 000 (>80%) 图像进行分析，从而节省时间和金钱。结论 结果表明，雌性大角羊的估计丰度与远程摄像机部署时间之间存在渐近关系。含义 本研究中使用的标记-重新观察方法适用于其他有蹄类动物，在这些有蹄类动物中，个体被无线电项圈固定或使用设置在水源、小道交叉口或矿物舔舐处的远程摄像机进行标记。这些发现可以帮助研究人员降低用于有蹄类动物种群监测的远程摄像机照片的设置、维护、存档和分析成本。结论 结果表明，雌性大角羊的估计丰度与远程摄像机部署时间之间存在渐近关系。含义 本研究中使用的标记-重新观察方法适用于其他有蹄类动物，在这些有蹄类动物中，个体被无线电项圈固定或使用设置在水源、小道交叉口或矿物舔舐处的远程摄像机进行标记。这些发现可以帮助研究人员降低用于有蹄类动物种群监测的远程摄像机照片的设置、维护、存档和分析成本。结论 结果表明，雌性大角羊的估计丰度与远程摄像机部署时间之间存在渐近关系。含义 本研究中使用的标记-重新观察方法适用于其他有蹄类动物，在这些有蹄类动物中，个体被无线电项圈固定或使用设置在水源、小道交叉口或矿物舔舐处的远程摄像机进行标记。这些发现可以帮助研究人员降低用于有蹄类动物种群监测的远程摄像机照片的设置、维护、存档和分析成本。