Nonbreeding distributions of four declining Nearctic-Neotropical migrants are predicted to contract under future climate and socioeconomic scenarios

Climate and land use/land cover change are expected to influence the stationary nonbreeding distributions of 4 Nearctic-Neotropical migrant bird species experiencing population declines: Canada Warbler (Cardellina canadensis), Cerulean Warbler (Setophaga cerulea), Golden-winged Warbler (Vermivora chrysoptera), and Wood Thrush (Hylocichla mustelina). Understanding how and where these species’ distributions shift in response to environmental drivers is critical to inform conservation planning in the Neotropics. For each species, we quantified current (2012-2021) and projected future (2050) suitable climatic and land use/land cover conditions as components of stationary nonbreeding distributions. Multi-source occurrence data were used in an ensemble modeling approach with covariates from 3 global coupled climate models (CCSM-ESM2, FIO-ESM-2-0, MIROC-ES2L) and 2 shared socioeconomic pathways (SSP2-RCP4.5, SSP5-RCP8.5) to predict distributions in response to varying climatic and land use/lan..., Bird Occurrence Data We obtained current (2012-2021) bird occurrence data containing only Neotropical presence records from eBird (accessed in January 2023; Sullivan et al. 2009) and supplemented with species-specific georeferenced occurrence datasets to bolster presence record sample sizes and the spatial representation of records. 2012-2021 was identified as the ‘current’ timeframe to capitalize on increased user engagement with eBird and align with prior research (Hightower et al. 2023). Date ranges for the stationary nonbreeding period were defined using expert input (N. Bayly, E. Cohen, I. Davidson, A. González, J. Hightower, J. L. Larkin, E. Montenegro, D. Raybuck, A. Roth, C. Rushing, C. Stanley, R. L. M. Stewart, and S. Wilson personal communication) to assess frequency distributions of daily presence records in the current timeframe. Experts emphasized date selection 2 weeks before or after most birds initiated or completed migration through the Neotropical flyway to minimize ..., , # Nonbreeding distributions of four declining Nearctic-Neotropical migrants are predicted to contract under future climate and socioeconomic scenarios [https://doi.org/10.5061/dryad.g1jwstr0h](https://doi.org/10.5061/dryad.g1jwstr0h) ## Description of the data and file structure The following data are available for use: covariates, spatial extents, presence record CSVs, and Honduras focal areas in the 'Processes to Identify Near-term Conservation Priority Areas' methods section. Covariates are available for the current (2012-2021) and future (2050) time periods. The current timeframe for Brodie et al. 2024 was designated as 2012-2021 to align with prior research and capitalize on increased user engagement with eBird. The 2050 data is split into SSP2-RCP4.5 (best-case) and SSP5-RCP8.5 (worst-case) climate and socioeconomic scenarios. The best-case represents a future where climate-smart practices increase and non-renewable resource use declines. In contrast, the worst-case represents ...# 未来气候与社会经济情景下4种种群衰退的新北区-新热带区迁徙鸟类（Nearctic-Neotropical migrant bird）的非繁殖分布区预计缩减 气候与土地利用/土地覆被变化预计将对4种种群衰退的新北区-新热带区迁徙鸟类的停留期非繁殖分布区（stationary nonbreeding distributions）产生影响，分别为加拿大林莺（*Cardellina canadensis*）、天蓝林莺（*Setophaga cerulea*）、金翅林莺（*Vermivora chrysoptera*）及棕林鸫（*Hylocichla mustelina*）。明晰这些物种的分布如何响应环境驱动因子发生变化，以及变化发生的区位，对于为新热带区的保护规划提供科学依据至关重要。 针对每个物种，本研究量化了其停留期非繁殖分布区的当前（2012-2021年）与预测未来（2050年）适宜气候及土地利用/土地覆被条件。本研究采用多源出现数据，结合3个全球耦合气候模式（global coupled climate models）：CCSM-ESM2、FIO-ESM-2-0、MIROC-ES2L，以及2种共享社会经济路径（shared socioeconomic pathways，SSP）：SSP2-RCP4.5、SSP5-RCP8.5的协变量，通过集合建模（ensemble modeling）方法预测物种分布对不同气候与土地利用/土地覆被变化的响应。 ## 鸟类出现数据集 我们从eBird平台（2023年1月获取；Sullivan等，2009）获取了仅包含新热带区出现记录的2012-2021年鸟类出现数据，并补充了针对各物种的地理参考出现数据集，以提升出现记录的样本量与空间代表性。选取2012-2021年作为"当前"时间窗口，一是为了充分利用eBird平台用户参与度提升的契机，二是为了与既往研究（Hightower等，2023）保持一致。 停留期非繁殖期的时间范围通过专家咨询确定（N. Bayly、E. Cohen、I. Davidson、A. González、J. Hightower、J. L. Larkin、E. Montenegro、D. Raybuck、A. Roth、C. Rushing、C. Stanley、R. L. M. Stewart及S. Wilson，私人通信），以分析当前时间窗口内每日出现记录的频率分布。专家强调，时间选取应覆盖多数鸟类通过新热带区迁飞通道开始或完成迁徙前后的两周时段，以尽可能减少[内容被截断]。 [https://doi.org/10.5061/dryad.g1jwstr0h](https://doi.org/10.5061/dryad.g1jwstr0h) ## 数据与文件结构说明 本数据集包含以下可用内容：协变量、空间范围、出现记录CSV文件，以及"识别近期保护优先区域"方法章节中提及的洪都拉斯重点区域。协变量涵盖当前（2012-2021年）与未来（2050年）两个时间阶段。 Brodie等（2024）将当前时间窗口设定为2012-2021年，目的是与既往研究保持一致，并充分利用eBird平台用户参与度提升的契机。2050年的数据被划分为SSP2-RCP4.5（最优情景）与SSP5-RCP8.5（最差情景）两种气候与社会经济情景。最优情景代表未来气候友好型实践不断推广、不可再生资源使用持续减少的发展路径；与之相对，最差情景则代表[内容被截断]。