Estimating nest-level phenology and reproductive success of colonial seabirds using time-lapse cameras
Estimating nest-level phenology and reproductive success of colonial seabirds using time-lapse cameras
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DOI：
10.1111/2041-210x.13015
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发表时间：
2018-08-01
影响因子：
6.6
通讯作者：
Southwell, Colin
中科院分区：
文献类型：
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作者：
Hinke, Jefferson T.;Barbosa, Andres;Southwell, Colin
1.收集空间广泛的物候和繁殖成功的数据是重要的海鸟保护和管理，但在偏远地区的后勤挑战。自主延时相机系统提供了提供这种覆盖的机会。我们描述了一种方法来估计巢级繁殖物候和繁殖成功的殖民pygoscelid企鹅使用延时相机的照片。该方法源于巢出席，其中主要是两个成年人之前和期间铺设，但切换到一个成年人在孵化的定型模式。开关近似离合器完成的日期，并估计拟合平滑样条每日巢出勤数据，确定候选日期，从两个成年人切换到一个和选择的日期时，样条的一阶导数最小化。离合器开始和孵化日期，然后估计从平均值，产卵（pygoscelid企鹅通常下两个蛋）和孵化期的持续时间之间的物种特异性的时间间隔。我们估计这些时间间隔为每个物种的历史现场数据。当照片显示蛋或小鸡在估计的产蛋或孵化日期之前出现时，调整物候。每个研究巢中存活的雏鸟数量决定了繁殖成功率的估计。通过对每个物种的同步直接观测验证了该方法的有效性，并将其应用于南极半岛地区的相机网络，以证明其实用性.来自直接观察的平均产卵和孵化间隔在各研究中心的种属内相似。在验证研究中，照片和直接观察之间的平均窝卵开始、孵化和产崽日期通常相等。生殖成功的估计是相同的。将该方法应用于延时网络表明整个地区所有物种的繁殖成功率相对较高，并证实了对纬度趋势和物种水平可塑性的一般理解。该方法准确地估计了相对于直接观测的物候和繁殖成功率，并且似乎非常适合于操作区域延时相机网络。估计方法应适用于其他海鸟与刻板的巢出席模式，繁殖物候可以估计。
1. Collecting spatially extensive data on phenology and reproductive success is important for seabird conservation and management, but can be logistically challenging in remote regions. Autonomous time-lapse camera systems offer an opportunity to provide such coverage.2. We describe a method to estimate nest-level breeding phenology and reproductive success of colonial pygoscelid penguins using photographs from time-lapse cameras. The method derives from stereotypical patterns of nest attendance, where predominantly two adults are present before and during laying, but switch to one adult during incubation. The switch approximates the date of clutch completion and is estimated by fitting a smoothing spline to daily nest attendance data, identifying candidate dates that switch from two adults to one and selecting the date when the first derivative of the spline is minimized. Clutch initiation and hatch dates are then estimated from the mean, species-specific interval between laying (pygoscelid penguins typically lay two eggs) and the duration of the incubation period. We estimated these intervals for each species from historical field data. The phenology is adjusted when photographs indicate egg or chick presence prior to their estimated lay or hatch dates. The number of chicks alive in each study nest on its creche date determines reproductive success estimates. The method was validated with concurrent direct observations for each species and then applied to a camera network in the Antarctic Peninsula region to demonstrate its utility.3. Mean egg laying and incubation intervals from direct observations were similar within species across sites. In the validation study, the mean clutch initiation, hatch and creche dates were generally equivalent between photographs and direct observations. Estimates of reproductive success were identical. Applying the method to a time-lapse network suggested relatively high reproductive success for all species across the region and corroborated general understanding of latitudinal trends and species-level plasticity in phenology.4. The method accurately estimated phenology and reproductive success relative to direct observations and appears well-suited to operationalize regional time-lapse camera networks. The estimation method should be applicable for other seabirds with stereotypical nest attendance patterns from which breeding phenology could be estimated.