We analyzed the reproductive success of eastern bluebirds (Sialia sialis) nesting in apple orchards and non-orchard nest-boxes in southern Ontario, Canada, from 1988 to 2018. Using data from 2397 nest-boxes monitored at 20 orchard sites and 52 non-orchard sites, we first modeled phenological parameters typically linked to climate change across both site types. We found that the first egg of each brood was laid significantly earlier in the season each year over our 31-year study. Clutch initiation occurred 4 days earlier in the spring in 2018 compared to 1988. Average clutch size in the first or second brood did not change significantly during our 31-year study; however, clutches were significantly smaller in orchards compared to non-orchards (0.10 ± 0.03 fewer eggs between sites). Nests built in orchards were also at 6.1-fold greater risk of parasitism and 2.1-fold greater risk of depredation than nests in non-orchards. After accounting for depredation and nest parasitism, hatching success was still significantly lower in orchards than in non-orchards. Overall, hatching success was 4%–5% lower in orchards. The probability of successfully fledging did not differ significantly between site types. In 2012, a ban on use of the organophosphate insecticide azinphos-methyl in orchards was enacted in Canada. We did not find a difference in hatching or fledging success in orchards after the ban. In our assessment of available data, we conclude that any pesticide effect on hatching success of eastern bluebirds in sprayed orchards is most likely the consequence of long-term exposure to dichlorodiphenyltrichloroethane (DDT) compounds in orchard soils and bioaccumulation in eggs rather than pesticides in use since regulation of DDT in the 1970s. Environ Toxicol Chem 2021;40:3369–3378. © 2021 Her Majesty the Queen in Right of Canada. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. Reproduced with the permission of the Minister of Environment and Climate Change Canada.

中文翻译：

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蓝鸟在常规喷洒的苹果园栖息地的孵化成功率受损：一项 31 年的研究

我们分析了东部蓝鸟（Sialia sialis) 从 1988 年到 2018 年在加拿大安大略省南部的苹果园和非果园巢箱中筑巢。使用在 20 个果园地点和 52 个非果园地点监测的 2397 个巢箱的数据，我们首先模拟了通常与两种站点类型的气候变化。我们发现，在我们长达 31 年的研究中，每一窝的第一个蛋在每年的季节里产得很早。与 1988 年相比，2018 年春季的离合器开始时间提前 4 天。在我们 31 年的研究中，第一代或第二代的平均离合器大小没有显着变化；然而，与非果园相比，果园中的离合器明显更小（场地之间的鸡蛋少 0.10 ± 0.03）。建在果园里的巢穴被寄生的风险也高出 6.1 倍和 2 倍。被掠夺的风险比非果园中的巢穴高 1 倍。在考虑了掠夺和巢寄生之后，果园的孵化成功率仍然明显低于非果园。总体而言，果园的孵化成功率降低了 4%–5%。成功羽化的概率在站点类型之间没有显着差异。2012 年，加拿大颁布了禁止在果园中使用有机磷杀虫剂谷硫磷的禁令。我们没有发现禁令后在果园中孵化或孵化成功的差异。在我们对可用数据的评估中，环境毒物化学2021；40:3369–3378。© 2021 加拿大女王陛下。Wiley Periodicals LLC 代表 SETAC 出版的Environmental Toxicology and Chemistry 。经加拿大环境与气候变化部长许可转载。