Combined effects of cold snaps and agriculture on the growth rates of Tree Swallows (<em>Tachycineta bicolor</em>)

The decline of avian aerial insectivores has been greater than any other foraging guild and both climate change and agricultural intensification are leading hypotheses explaining this decline. Spring cold snaps are predicted to increase in frequency due to climate change, and factors associated with agricultural intensification (e.g., toxicological agents, simplification of agricultural landscapes, and reductions of insect prey) potentially exacerbate the negative effects of cold snaps on aerial insectivore nestling growth and body condition. We evaluated this hypothesis using repeated measures of Tree Swallow (Tachycineta bicolor (Vieillot, 1808)) nestling body mass and 9th primary length across an expansive gradient of agricultural intensification. Growth rate, asymptotic body mass, and near-fledging 9th primary length were lower for nestlings in landscapes consisting of more agro-intensive monocultures. This 14-year dataset of body measures occurring at 2, 6, 12, and 16 days of age s..., , , # Data from: Combined effects of cold snaps and agriculture on the growth rates of Tree Swallows (*Tachycineta bicolor*) [https://doi.org/10.5061/dryad.z08kprrgj](https://doi.org/10.5061/dryad.z08kprrgj) ## Description of the data and file structure Data sets used in the determination of how agricultural cover and the appearance of cold snap (days where the maximum observed temperature fell below 18.2 °C) interact to impact the growth rates of Tree Swallows breeding within southern Quebec, Canada. The following are the definitions of the columns found in data sets. The data set names describe the contents of each data set. The text fine and coarse in the data set name refers to the fine and coarse temporal scale used in the formal analysis, respectively. ### Files and variables • Brood.id = Unique brood identification • Nestling.id = Unique nestling identification • Year = Breeding season (Year between 2006 and 2019) • Farm = Unique farm identification • NestBox = Unique nest b...,食虫飞禽（avian aerial insectivores）的种群衰退幅度远超其他觅食类群，气候变化与农业集约化是解释该衰退现象的两大主流假说。据预测，气候变化将导致春季寒潮发生频率上升；而与农业集约化相关的诸多因素（如有毒药剂、农业景观单一化以及昆虫猎物资源减少），可能会加剧寒潮对食虫飞禽雏鸟生长与身体状况的负面影响。本研究通过在大范围农业集约化梯度下，对树燕（Tree Swallow，Tachycineta bicolor (Vieillot, 1808)）雏鸟的体重及第9枚初级飞羽长度进行重复测量，对上述假说进行了验证。在以高度集约化农业单作景观为主的区域中，雏鸟的生长速率、渐近体重以及临近出飞时的第9枚初级飞羽长度均更低。本数据集涵盖了14年间雏鸟在2、6、12及16日龄时的身体测量数据…… # 数据来源：寒潮与农业活动对树燕（*Tachycineta bicolor*）生长速率的联合影响 [https://doi.org/10.5061/dryad.z08kprrgj](https://doi.org/10.5061/dryad.z08kprrgj) ## 数据与文件结构说明 本数据集用于探究农业覆盖度与寒潮（观测最高气温低于18.2℃的日期）的交互作用对加拿大魁北克南部繁殖树燕生长速率的影响。下文将对数据集中各列的定义进行说明。数据集名称可反映其包含的内容，数据集名称中的"fine（精细）"与"coarse（粗糙）"分别指代正式分析中所采用的精细与粗略时间尺度。 ### 文件与变量 • 窝次ID（Brood.id）：唯一窝次标识 • 雏鸟ID（Nestling.id）：唯一雏鸟标识 • 年份（Year）：繁殖季（2006年至2019年） • 农场ID（Farm）：唯一农场标识 • 巢箱编号（NestBox）：唯一巢箱标识……