The Prairie Habitat Joint Venture (PHJV) delivers conservation programs for the Canadian portion of the Prairie Pothole Region under the North American Waterfowl Management Plan. The PHJV Assessment was designed to evaluate biological assumptions and effectiveness of PHJV conservation activities. Our objectives were to 1) test whether waterfowl reproductive success increased in response to the full suite of PHJV habitat treatments, and 2) quantify the relationships between mallard (Anas platyrhynchos) vital rates and landscape variables. We focused on examining the association of mallard vital rates with covariates measured at the study‐area scale. We collected information on vital rates from 3,214 radio‐marked female mallards at 27 study areas mainly throughout the Aspen Parkland ecoregion of Manitoba, Saskatchewan, and Alberta in 1993–2000. We used a modeling framework and information‐theoretic techniques to test hypotheses about putative effects of environmental covariates on adult female and duckling survival, nesting effort, and nest survival. Additionally, we constructed a stage‐based matrix projection model of mallard population growth (λ) to estimate the sensitivities of population growth rates to variation in vital rates. Nest survival was positively related to the amount of herbaceous vegetation on study areas and total precipitation for the 12 months prior to nesting. Nesting effort was positively related to wetland inundation in July. Duckling survival was positively related to the proportion of seasonal wetlands holding water in July and negatively related to the number of days in June and July when the minimum air temperature dropped below 10° C. Adult female survival rate was positively related to both the proportions of grassland and wetland habitats measured at the study‐area scale (65 km²), though these factors interacted such that the positive relationship with proportion of wetlands was strongest on study sites with high proportions of grassland. The stage‐based projection model constructed using mean vital rates indicated that populations were declining (mean λ = 0.95, median λ = 0.98, 5th percentile = 0.68, 95th percentile = 1.38). Variance‐stabilized sensitivities indicated that population growth was most responsive to variation in vital rates for after‐second‐year birds and that nest survival was the single vital rate to which populations were most sensitive. A prospective simulation revealed that, as expected, sensitivity to nest survival is likely to decrease at higher levels of nest survival. Despite evidence that nest survival was higher in PHJV habitat treatments than surrounding habitats, our a priori PHJV treatment index was unrelated to mallard vital rates estimated at the 65‐km² scale. Although mallard populations were affected by several weather variables and land uses, efforts to increase populations should focus on improving nest survival rates, which currently are below approximately 30%. © 2014 The Wildlife Society.

中文翻译：

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加拿大阿斯彭草原野鸭活命率的变化：草原人居合资企业评估

根据北美水禽管理计划，草原人居合资企业（PHJV）为草原坑洼地区的加拿大部分提供保护计划。PHJV评估旨在评估PHJV保护活动的生物学假设和有效性。我们的目标是：1）测试整套PHJV生境处理对水禽繁殖成功的促进作用，以及2）量化野鸭（Anas platyrhynchos）之间的关系）的生命率和景观变量。我们重点研究了野鸭生命率与在研究区域范围内测量的协变量之间的关系。在1993–2000年间，我们从27个研究区域的3,214个具放射性标记的雌性野鸭收集了重要生命率的信息，主要分布在曼尼托巴省，萨斯喀彻温省和艾伯塔省的阿斯彭帕克兰生态区。我们使用了建模框架和信息理论技术来测试有关环境协变量对成年雌性和小鸭生存，筑巢工作量和巢生存的假定影响的假设。此外，我们构建了野鸭种群增长（λ）以估算人口增长率对生命率变化的敏感性。筑巢前12个月内，巢穴存活与研究区草本植物的数量和总降水量呈正相关。筑巢工作与7月的湿地淹没呈正相关。小鸭存活率与7月份季节性持水的湿地比例成正比，与6月和7月最低气温降至10°C以下时的天数成负相关。成年雌性成活率与这两个比例成正比。在研究区域范围内测量的草地和湿地栖息地（65 km ²），尽管这些因素相互作用，使得在草地比例高的研究地点与湿地比例的正相关性最强。使用平均生命率构建的基于阶段的投影模型表明，人口正在下降（平均λ  = 0.95，中位数λ = 0.98，第5个百分位数= 0.68，第95个百分位数= 1.38）。方差稳定的敏感性表明，种群增长对第二年以后的鸟类的生命率变化最敏感，而巢生存是种群最敏感的单个生命率。预期的模拟结果表明，如预期的那样，在较高的巢生存水平下，对巢生存的敏感性可能会降低。尽管有证据表明在PHJV生境处理中巢生存比周围生境高，但我们的先验PHJV处理指数与在65 km ^2时估计的野鸭生命率无关。规模。尽管野鸭种群受到几种天气变量和土地利用的影响，但增加种群的努力应集中在提高巢生存率上，目前该巢生存率低于30％。©2014野生动物协会。