Ten polymorphic autosomal microsatellite loci for the Eider duck Somateria mollissima and their cross‐species applicability among waterfowl species (Anatidae)

We describe the isolation and characterization of the first microsatellite loci specifically developed for the Common Eider duck, Somateria mollissima. Our 10 loci show Mendelian inheritance and no linkage disequilibrium between any pair of loci. In the Eider duck, we observed between two and 16 alleles per locus, an expected heterozygosity between 0.31 and 0.97, and an observed heterozygosity between 0.14 and 1.00. Most primers also yield reproducible results in several other anatid species. These loci comprise a set of autosomal molecular markers for various applications, from moderately polymorphic loci suitable for population studies to highly polymorphic loci for pedigree analysis in waterfowl.     

濒危植物多毛坡垒种子萌发的生理生态特性

研究了多毛坡垒（Hopea mollissima）种子在自然条件下的寿命及成熟度、温度、光照、土壤水分条件对多毛坡垒种子萌发的影响,结果表明：多毛坡垒种子适宜萌发的温度范围是20～30℃,最适宜温度为25℃;光照对多毛坡垒种子的萌发没有显著性影响,但在周期性光照条件下以25～30℃萌发结果最好,全黑暗条件下以20～25℃萌发结果最好;种子适宜萌发的土壤含水量为20％～60％,最适含水量为50％～60％;种子成熟后在树上长时间宿存明显降低了种子的发芽率和活力;在室内自然摊放条件下,10天后发芽率减半,16天后完全丧失发芽能力。研究认为,该物种对热带湿性季节性雨林原生境有很强的依赖性,目前多毛坡牟的濒危状态主要是由于滥砍乱伐和森林破坏造成的,由于其种子具有顽拗性种子的一些特点,日前该物种宜采取活体保仔的方法,以就地保护为主,活植物迁地保护为辅。     

板栗在6个同工酶位点上的遗传变异

利用水平板淀粉凝胶电泳技术检验了板栗8个居群在6个同工酶位点（Per-2、Got-2、Est-2、Gpi-2、Idh-1、Idh-2 )上的遗传变异（多态位点百分率为97.9%,平均等位基因数为2.54,平均预期杂合值为0.452 ) 。在同一水平上,其遗传多样性水平显著高于欧洲栗。总的基因多样性中,89.2%发生在居群内,10.8%发生于居群间,各居群之间的遗传距离为0.036～0.394,有些居群分化较大,尤其在个别位点上更为明显。初步研究表明,其丰富的遗传变异及其高水平的分化度可能与其生境的多样性、风媒异交等因素造成的长距离的基因漂变有关。     

Evidence of Recent Population Recovery in Common Eiders Breeding in Western Greenland

ABSTRACT Severe population declines were reported for common eiders (Somateria mollissima) in western Greenland over the period 1960–2000. A monitoring program, concurrent with more restrictive hunting regulations on common eiders, revealed breeding numbers increasing by 212%, from 2,558 active nests in 2000 to 7,982 nests in 2007. Though it was not possible to directly link harvest reduction and population growth in West Greenland, a similar increase in breeding numbers in Canada was correlated with the harvest reduction in Greenland and linked to increasing adult survival and recruitment of first-time breeders, and a similar explanation is suggested for West Greenland. The study emphasizes that appropriate restrictions in hunting can be efficient in wildlife management and that common eiders can sustain dramatic rates of increase during population regrowth. It also shows that cost-efficient monitoring programs can be established through cooperation with local residents.     

Female pre-nesting foraging and male vigilance in Common Eider Somateria mollissima

Foraging activity and behaviour of paired female Common Eider from arrival to laying at Saltholm, Denmark, was studied during the spring of 1994 and 1995 to assess the importance of female resource accumulation just prior to egg-laying. Ovary development was studied in paired females collected in 1995, 1996 and 1998. Male activity and behaviour were recorded in 1996 in order to assess the importance of mate-guarding in optimizing female resource acquisition. From arrival at the colony in late March until laying in mid-April, female Eiders allocated on average 62% of the daylight hours to foraging by dabbling in inshore waters (<1 m water depth). In offshore waters (1–4 m depth) foraging by diving averaged 74% of the daylight hours. Paired males foraged an average of 17% of the day time in the inshore habitat, and closely attended their females during this time. The males actively defended their females in encounters with other pairs and from single males. Defence events involving encounters with single males increased significantly from 9.2 times per hour to 17.5 times per hour by the time of laying. The frequency of interruption to female foraging did not change significantly as a result of the more frequent encounters towards the time of laying, being 4.0 times per hour before early April and 5.8 times per hour at the time of laying. Female ovary weights showed a significant increase from early April, indicating that resources obtained locally were allocated to egg production. The increase in encounters with single males suggests that extra-pair copulation may be a secondary reproductive strategy in male Eiders at the time their females start to incubate. The present results emphasize the importance of pre-nesting foraging for female Eiders in maximizing the nutrient intake in preparation for reproduction, and the importance of the behaviour of attendant males in protecting female foraging from interruptions from other males.     

Effects of Midazolam on Corticosterone and Blood Gases in Spectacled Eiders Prior to Transmitter Implantation

Stress and physical exertion may affect the physiology and behavior of wildlife during and after capture, and consequently, survival following release. Such effects may reduce the quality and quantity of the data obtained from captured wildlife. We captured spectacled eiders (Somateria fischeri), a species listed as threatened under the United States Endangered Species Act, in western Alaska, USA, during spring 2018 for surgical implantation of satellite transmitters. We evaluated the efficacy of midazolam, a benzodiazepine sedative given at capture, to reduce stress and physical exertion. We dosed spectacled eiders with either midazolam (5 mg/ml, = 2.2 mg/kg intramuscular; n = 20) or saline (0.7 ml intramuscular; n = 20) at the point of capture. We assessed sedation level and collected blood samples upon arrival to the field surgery site and at anesthetic induction. We found that midazolam reduced mean corticosterone concentration by 29% and median lactate concentration by 30.3% at the mean arrival time (42 min post-dosing) relative to the control group. These effects had abated by the mean induction time (99 min post-dosing). Unexpectedly, blood pH was reduced in the midazolam treatment relative to controls at both arrival and induction, which likely resulted from sedative-induced respiratory depression that was easily treated with intubation and mechanical ventilation, and administration of the reversal drug, flumazenil. Low blood pH was not associated with negative post-surgical outcomes, as had been found in spectacled eiders with acidosis caused by anaerobic metabolism typical of physical exertion. Intramuscular injection of midazolam in the field effectively reduced stress and physical exertion in spectacled eiders prior to surgical implantation of transmitters. © 2021 The Wildlife Society.     

Use of the Beaufort Sea by King Eiders Breeding on the North Slope of Alaska

Abstract: We estimated areas used by king eiders (Somateria spectabilis) in the Alaskan Beaufort Sea, how distributions of used areas varied, and characteristics that explained variation in the number of days spent at sea, to provide regulatory agencies with baseline data needed to minimize impacts of potential offshore oil development. We implanted sixty king eiders with satellite transmitters at nesting areas on the North Slope of Alaska, USA, in 2002-2004. More than 80% of marked eiders spent >2 weeks staging offshore prior to beginning a postbreeding molt migration. During postbreeding staging and migration, male king eiders had much broader distributions in the Alaskan Beaufort Sea than female eiders, which were concentrated in Harrison and Smith Bays. Distribution did not vary by sex during spring migration in the year after marking. Shorter residence times of eiders and deeper water at locations used during spring migration suggest the Alaskan Beaufort Sea might not be as critical a staging area for king eiders during prebreeding as it is postbreeding. Residence time in the Beaufort Sea varied by sex, with female king eiders spending more days at sea than males in spring and during postbreeding. We conclude the Alaskan Beaufort Sea is an important staging area for king eiders during postbreeding, and eider distribution should be considered by managers when mitigating for future offshore development. We recommend future studies examine the importance of spring staging areas outside the Alaskan Beaufort Sea.