RAPID: Population viability below the quasi-extinction threshold

RAPID：种群生存能力低于准灭绝阈值

• 批准号: 1920834
• 负责人: Elizabeth Crone
• 金额: $ 19.49万
• 依托单位: Tufts University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-02-15 至 2022-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1920834&HistoricalAwards=false
• 关键词: RAPID; Population; viability; below; quasi

From time to time, formerly widespread species have declined to extinction. For example, passenger pigeons were once abundant throughout North America, but no longer exist. We often know about the factors that cause a widespread species to decline (in the case of the passenger pigeon, the original cause was hunting), but we know much less about what causes some populations to recover, and others not to do so, once that original cause of declines is gone. Monarch butterfly populations have declined dramatically in North America, and now western populations may be approaching extinction. In the 1980?s, millions of monarch butterflies overwintered on the California coast, and bred during the summer west of the Rocky Mountains. By the 2000?s, the overwintering population had declined to ~200,000-300,000 butterflies. In 2018, the population dropped to ~30,000 butterflies. This RAPID project will use the unexpected, rapid decline of western monarch butterflies to test theories of extinction risk. We will evaluate what changes in this suddenly-small population, through a combination of carefully controlled experiments and sightings reported by volunteers looking for monarch butterflies throughout the west, especially in California. We will use this knowledge to help guide management and recovery of this iconic butterfly population.The research will test the hypothesis that vital rates, like survival and reproduction, decline as populations become very small, perhaps because individual animals have difficulty finding mates, or cannot protect themselves from predators as well as they could in groups. If very small populations decline due to these "Allee effects", there is a fleeting window of time in which to study population dynamics before local population extinction. Because we know so little about suddenly-small populations, ecologists typically base conservation plans on predicting declines to a ?quasi-extinction threshold?, in other words, a population size below which the species is unlikely to be able to recover. Based upon estimates of survival on overwintering grounds and reproduction in early spring, earlier work warned that 30,000 butterflies may be a quasi-extinction threshold for western monarchs. This project will (1) Test whether winter survival and spring reproduction are now lower than they were in the past; (2) Calculate rates of summer range expansion, and compare 2019 to years in the recent past, to evaluate potential reductions of survival, reproduction, or movement at other life stages; (3) Combine results of (1) & (2) with existing data to model dynamics of this migratory population through its full annual cycle. This model will be used to calculate annual population growth rates in small and large populations, and also to evaluate the potential of different management strategies to help western monarch butterflies recover from quasi-extinction.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

有时，以前广泛分布的物种已经走向灭绝。例如，旅鸽曾经遍布北美，但现在已经不复存在。我们通常知道导致一个广泛分布的物种减少的因素（在旅鸽的例子中，最初的原因是狩猎），但我们对一旦减少的原始原因消失，是什么导致一些种群恢复，而另一些种群却没有恢复的原因知之甚少。帝王蝶的数量在北美急剧下降，现在西方的数量可能接近灭绝。在1980年？年代，数以百万计的帝王蝶在加州海岸过冬，并在落基山脉以西的夏季繁殖。到2000年？到2000年，越冬蝴蝶数量已下降到约20万至30万只。2018年，蝴蝶数量下降至约30，000只。这个RAPID项目将利用西方帝王蝶的意外、快速下降来测试灭绝风险理论。我们将通过仔细控制的实验和志愿者在整个西部，特别是在加州寻找帝王蝶的目击报告来评估这个突然变小的种群的变化。我们将利用这些知识来帮助指导这种标志性蝴蝶种群的管理和恢复。这项研究将测试这样一种假设，即随着种群变得非常小，生命率，如生存和繁殖，会下降，这可能是因为个体动物难以找到配偶，或者无法像在群体中那样保护自己免受捕食者的伤害。如果非常小的人口下降，由于这些“阿利效应”，有一个短暂的时间窗口，在其中研究人口动态之前，当地人口灭绝。因为我们对突然减少的种群知之甚少，生态学家通常将保护计划建立在预测种群数量下降到？准灭绝阈值换句话说，低于这个数量，物种就不可能恢复。根据对越冬地生存和早春繁殖的估计，早期的工作警告说，30，000只蝴蝶可能是西方君主的准灭绝阈值。该项目将（1）测试冬季生存和春季繁殖现在是否低于过去;（2）计算夏季范围扩张的速度，并将2019年与最近的几年进行比较，以评估其他生命阶段的生存，繁殖或运动的潜在减少;（3）将（1）（2）的结果与现有数据相结合，以模拟这种迁徙种群在整个年度周期中的动态。该模型将用于计算小型和大型种群的年种群增长率，并评估不同管理策略的潜力，以帮助西部帝王蝶从准灭绝中恢复过来。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Estimating abundance and phenology from transect count data with GLMs

• DOI: 10.1111/oik.08368
• 发表时间: 2021-05-16
• 期刊: OIKOS
• 影响因子: 3.4
• 作者: Edwards, Collin B.;Crone, Elizabeth E.
• 通讯作者: Crone, Elizabeth E.

Western Monarch Population Plummets: Status, Probable Causes, and Recommended Conservation Actions

西部帝王蝶种群数量急剧下降：现状、可能原因和建议的保护行动

• DOI: 10.3389/fevo.2019.00258
• 发表时间: 2019
• 期刊: Frontiers in Ecology and Evolution
• 影响因子: 3
• 作者: Pelton, Emma M.;Schultz, Cheryl B.;Jepsen, Sarina J.;Black, Scott Hoffman;Crone, Elizabeth E.
• 通讯作者: Crone, Elizabeth E.