Directional bias in movement while searching for a food reward during spatial cognitive tasks in mountain chickadees (Poecile gambeli)

Data analyzed in 2022. All data were collected as part of a long-term study (2014 - ongoing in 2022) of mountain chickadees at Sagehen Experimental Forest in the Sierra Nevada mountains (Sagehen Creek Field Station, University of California Berkeley), located 10 km north of Truckee, CA, USA. To band birds, birds were trapped annually at nestboxes during summer or at established bird feeders using mistnets in the fall and winter. Trapped birds were banded with color bands including a colored passive integrated transponder (PIT) tag with a unique alphanumeric ID (IB Technology, Leicestershire, U.K.). Sex (male or female) was determined from previous summer breeding survey records using physiological evidence (e.g., brood patch or cloacal protuberance), if possible. See published works for better characterization of banding efforts and cognition experiments: Branch et al. 2016, 2017; Kozlovsky et al. 2018, Tello-Ramos et al. 2018, Sonnenberg et al. 2019, Sonnenberg et al. 2020, Benedict et al. 2021. Directional bias was estimated in two was based on the direction that chickadees moved around an experimental apparatus during foraging-based search in several spatial cognitive tasks. Only trials with at least two location errors were analyzed (i.e. non-rewarding feeders), ensuring that chickadees had not yet learned the location of the correct rewarding feeder for each task. Initial bias was estimated from the relative direction birds moved between the first two location errors. Consistent bias was estimated when birds again moved in the same direction between the second and third visits as during the initial bias. Visits to feeders across the feeder array were not analyzed. The tasks included spatial learning and memory (winter 2019-2020, winter 2020-2021), single spatial reversal learning (winter 2019-2020, winter 2020-2021), and serial spatial reversal learning (winter 2020-2021). Data were collected automatically from 'smart' feeders equipped with a radio frequency identification (RFID) data logger connected to a perch-mounted antenna that detected and logged the PIT tags of birds that landed at the feeders. Each feeder had a mechanized door to control access to a supply of black oil sunflower seeds. Feeders were arranged in 8-feeder arrays on a square frame, 2 per elevation, ca. 1.2 km apart (based on established protocols, see Croston et al. 2016, 2017). This file contains the season of data collection, type of bias, individual bird ID, elevation (high or low), sex, total number of left-scored trials, total number of right-scored trials, total number of scored trials, bias index (calculated using a standard lateralization index), and several statistics for significant bias. These included a p-value from binomial tests (per bird), whether the resulting binomial p-value was significant using an alpha = .05 and bonferroni corrected alpha (.05/n birds) the Holm-adjusted p-value, the z-score, and z-score based bias (to estimate relative bias).本数据集的分析工作于2022年完成。所有数据均采集自一项针对山原山雀（mountain chickadees）的长期研究，该研究于2014年启动，截至2022年仍在进行，研究地点位于美国加利福尼亚州特拉基以北10公里的内华达山脉塞奇亨实验林（加州大学伯克利分校塞奇亨溪野外站）。为开展鸟类环志工作，研究人员每年夏季在巢箱处诱捕鸟类，或于秋冬季节利用雾网在已布设的鸟类喂食器处进行诱捕。诱捕得到的鸟类会被佩戴带有彩色无源集成应答器（passive integrated transponder, PIT）标签的彩色脚环，该标签带有唯一字母数字标识符，由英国莱斯特郡的IB Technology公司提供。若条件允许，将结合过往夏季繁殖调查记录与生理特征（如孵卵斑或泄殖腔突起）判定鸟类性别（雄性或雌性）。有关环志工作与认知实验的详细说明，请参阅已发表文献：Branch等2016、2017；Kozlovsky等2018；Tello-Ramos等2018；Sonnenberg等2019、2020；Benedict等2021。方向偏差通过两种方式进行估计，其依据为山原山雀在多项基于觅食搜索的空间认知任务中，于实验装置周围的移动方向。本研究仅分析至少出现2次位置偏差（即未获得奖励的喂食器）的试次，以确保山原山雀尚未掌握对应任务中奖励喂食器的位置。初始偏差通过鸟类前两次位置偏差间的相对移动方向进行估计。当鸟类在第二次与第三次到访时的移动方向与初始偏差方向一致时，即可判定存在持续性偏差。本研究未分析喂食器阵列中各喂食器的到访情况。所涉任务包括空间学习与记忆任务（2019-2020冬季、2020-2021冬季）、单次空间反转学习任务（2019-2020冬季、2020-2021冬季）以及序列空间反转学习任务（2020-2021冬季）。数据由配备射频识别（radio frequency identification, RFID）数据记录仪的"智能"喂食器自动采集，该记录仪与安装在栖木上的天线相连，可检测并记录停留在喂食器处鸟类的PIT标签。每个喂食器均配备机械化舱门，用于控制黑油向日葵籽的供应。喂食器以8个为一组布置在方形框架上，每组按海拔高度分为高低两组，两组间距约1.2公里（遵循既定实验规程，详见Croston等2016、2017）。本文件包含以下信息：数据采集季节、偏差类型、个体鸟类标识符、海拔组别（高海拔或低海拔）、性别、左侧评分试次总数、右侧评分试次总数、有效评分试次总数、偏差指数（采用标准偏侧化指数公式计算），以及用于检测显著性偏差的多项统计量，包括单只鸟类的二项检验p值、以α=0.05和邦弗朗尼校正α值（0.05/总鸟类数）判断的二项检验显著性结果、霍尔姆校正p值、z分数，以及基于z分数的相对偏差估计值。