PDF(Pubmed)
Abstract：
Parturition timing has long been a topic of interest in ungulate research. However, few studies have examined parturition timing at fine scale (e.g., <1 day). Predator activity and environmental conditions can vary considerably with diel timing, which may result in selective pressure for parturition to occur during diel times that maximize the likelihood of neonate survival. We monitored parturition events and early-life survival of elk (Cervus canadensis) and mule deer (Odocoileus hemionus) in Utah, USA to better understand diel timing of parturition in temperate ungulates. Diel timing of parturition was moderately synchronous among conspecifics and influenced by environmental variables on the date of parturition. For elk, parturition events were most common during the morning crepuscular period and generally occurred later (i.e., closer to 12:00) when a relatively large proportion of the moon was illuminated. For mule deer, parturition events were most common during the diurnal period and generally occurred later (i.e., closer to 15:00) on cold, wet dates. Diel timing of parturition did not influence neonate survival, but larger datasets may be required to verify the apparent lack of influence. Although additional work could evaluate alternative variables that might affect parturition timing, our data provide an improved and finer scale understanding of reproductive ecology and phenology in ungulates.
摘要：
分娩时机长期以来一直是有蹄类动物研究中感兴趣的话题。然而,很少有研究在精细尺度上检查分娩时机(例如，<1天)。捕食者的活动和环境条件可能会随着diel时间的变化而变化很大，这可能导致分娩的选择性压力发生在diel时间，最大限度地提高新生儿生存的可能性。我们监测了犹他州麋鹿（Cervuscanadensis）和m鹿（Odocoileushemionus）的分娩事件和早期生存，美国将更好地了解温带有蹄类动物的分娩时间。Diel的分娩时间在种属之间是适度同步的，并且在分娩之日受到环境变量的影响。对于麋鹿来说,分娩事件在早晨黄昏期间最常见，通常发生在以后(即，接近12:00)时，月球的相对较大比例被照亮。对于骡鹿来说，分娩事件在昼夜期间最常见，通常发生在以后(即，接近15:00）在寒冷时，湿日期。Diel的分娩时间不会影响新生儿的生存，但可能需要更大的数据集来验证明显缺乏影响力。虽然额外的工作可以评估可能影响分娩时机的替代变量，我们的数据提供了对有蹄类动物生殖生态和物候的更好和更精细的理解。
