Yang Louie H, Swan Karen, Bastin Eric, Aguilar Jessica, Cenzer Meredith, Codd Andrew, Gonzalez Natalie, Hayes Tracie, Higgins August, Lor Xang, Macharaga Chido, McMunn Marshall, Oto Kenya, Winarto Nicholas, Wong Darren, Yang Tabatha, Afridi Numan, Aguilar Sarah, Allison Amelia, Ambrose-Winters Arden, Amescua Edwin, Apse Mattias, Avoce Nancy, Bastin Kirstin, Bolander Emily, Burroughs Jessica, Cabrera Cristian, Candy Madeline, Cavett Ariana, Cavett Melina, Chang Lemuel, Claret Miles, Coleman Delaney, Concha Jacob, Danzer Paxson, DaRosa Joe, Dufresne Audrey, Duisenberg Claire, Earl Allyson, Eckey Emily, English Maddie, Espejo Alexander, Faith Erika, Fang Amy, Gamez Alejandro, Garcini Jackelin, Garcini Julie, Gilbert-Igelsrud Giancarlo, Goedde-Matthews Kelly, Grahn Sarah, Guerra Paloma, Guerra Vanessa, Hagedorn Madison, Hall Katie, Hall Griffin, Hammond Jake, Hargadon Cody, Henley Victoria, Hinesley Sarah, Jacobs Celeste, Johnson Camille, Johnson Tattiana, Johnson Zachary, Juchau Emma, Kaplan Celeste, Katznelson Andrew, Keeley Ronja, Kubik Tatum, Lam Theodore, Lansing Chalinee, Lara Andrea, Le Vivian, Lee Breana, Lee Kyra, Lemmo Maddy, Lucio Scott, Luo Angela, Malakzay Salman, Mangney Luke, Martin Joseph, Matern Wade, McConnell Byron, McHale Maya, McIsaac Giulia, McLennan Carolanne, Milbrodt Stephanie, Mohammed Mohammed, Mooney-McCarthy Morgan, Morgan Laura, Mullin Clare, Needles Sarah, Nunes Kayla, O'Keeffe Fiona, O'Keeffe Olivia, Osgood Geoffrey, Padilla Jessica, Padilla Sabina, Palacio Isabella, Panelli Verio, Paulson Kendal, Pearson Jace, Perez Tate, Phrakonekham Brenda, Pitsillides Iason, Preisler Alex, Preisler Nicholas, Ramirez Hailey, Ransom Sylvan, Renaud Camille, Rocha Tracy, Saris Haley, Schemrich Ryan, Schoenig Lyla, Sears Sophia, Sharma Anand, Siu Jessica, Spangler Maddie, Standefer Shaili, Strickland Kelly, Stritzel Makaila, Talbert Emily, Taylor Sage, Thomsen Emma, Toups Katrina, Tran Kyle, Tran Hong, Tuqiri Maraia, Valdes Sara, VanVorhis George, Vue Sandy, Wallace Shauna, Whipple Johnna, Yang Paja, Ye Meg, Yo David, Zeng Yichao
Department of Entomology and Nematology University of California Davis California USA.
Center for Land-Based Learning Woodland California USA.
Ecol Evol. 2022 Jul 11;12(7):e9039. doi: 10.1002/ece3.9039. eCollection 2022 Jul.
Seasonal windows of opportunity are intervals within a year that provide improved prospects for growth, survival, or reproduction. However, few studies have sufficient temporal resolution to examine how multiple factors combine to constrain the seasonal timing and extent of developmental opportunities. Here, we document seasonal changes in milkweed ()-monarch () interactions with high resolution throughout the last three breeding seasons prior to a precipitous single-year decline in the western monarch population. Our results show early- and late-season windows of opportunity for monarch recruitment that were constrained by different combinations of factors. Early-season windows of opportunity were characterized by high egg densities and low survival on a select subset of host plants, consistent with the hypothesis that early-spring migrant female monarchs select earlier-emerging plants to balance a seasonal trade-off between increasing host plant quantity and decreasing host plant quality. Late-season windows of opportunity were coincident with the initiation of host plant senescence, and caterpillar success was negatively correlated with heatwave exposure, consistent with the hypothesis that late-season windows were constrained by plant defense traits and thermal stress. Throughout this study, climatic and microclimatic variations played a foundational role in the timing and success of monarch developmental windows by affecting bottom-up, top-down, and abiotic limitations. More exposed microclimates were associated with higher developmental success during cooler conditions, and more shaded microclimates were associated with higher developmental success during warmer conditions, suggesting that habitat heterogeneity could buffer the effects of climatic variation. Together, these findings show an important dimension of seasonal change in milkweed-monarch interactions and illustrate how different biotic and abiotic factors can limit the developmental success of monarchs across the breeding season. These results also suggest the potential for seasonal sequences of favorable or unfavorable conditions across the breeding range to strongly affect monarch population dynamics.
季节性机遇窗口是指一年中能为生长、生存或繁殖提供更好前景的时间段。然而，很少有研究具备足够的时间分辨率来探究多种因素如何共同作用，限制发育机遇的季节性时间和范围。在此，我们记录了在西部帝王蝶种群单年急剧下降之前的最后三个繁殖季节里，马利筋（ ）与帝王蝶（ ）相互作用的高分辨率季节性变化。我们的结果显示，帝王蝶繁殖的早期和晚期机遇窗口受到不同因素组合的限制。早期机遇窗口的特征是在特定的寄主植物子集上卵密度高但存活率低，这与早春迁徙的雌性帝王蝶选择较早出现的植物以平衡寄主植物数量增加和质量下降之间的季节性权衡这一假设相符。晚期机遇窗口与寄主植物衰老的开始同时出现，毛虫的成功率与热浪暴露呈负相关，这与晚期机遇窗口受到植物防御特性和热应激限制的假设一致。在整个研究过程中，气候和微气候的变化通过影响自下而上、自上而下和非生物限制因素，在帝王蝶发育窗口的时间和成功方面发挥了基础性作用。在较凉爽的条件下，更多暴露的微气候与更高的发育成功率相关，而在较温暖的条件下，更多遮荫的微气候与更高的发育成功率相关，这表明栖息地异质性可以缓冲气候变化的影响。总之，这些发现揭示了马利筋 - 帝王蝶相互作用中季节性变化的一个重要方面，并说明了不同的生物和非生物因素如何在整个繁殖季节限制帝王蝶的发育成功。这些结果还表明，整个繁殖范围内有利或不利条件的季节性序列有可能强烈影响帝王蝶的种群动态。
