谁给南极带来了污点——笔走南极(五)

地球上还有干净的地方吗?比如像南极这样人迹罕至的地区。这里所说的干净,系指没有受到人类生活与生产污染的地方,它完全处于一种纯净的自然状态。 人类世居的各大洲,相关的国际组织和所有国家虽然制定了各种法规,以及采用各种环保技术对环境加以控制,也取得一定的成效,但是,其污染的事例仍然天天在发生,有些地方的污染程度还在加重。当人们发现污染已经危及自身生存的时候,便决心去治理,一个意味深长的口号便是“可持续性发展”。环境保护和环境治理这所以越来越受到重视,大家都觉得     

笔走南极(三)魂断冰海

倘若那三只狗还活在中国南极中山站,伏在地上,前爪使劲地按着鸡骨头,贪婪地用利齿撕咬着;倘若它们还快活地摇着尾巴,跟着队友们上山玩耍,这些狗昔日留给我的印象还不会几次闯入我的梦中,扰我安眠。     

危险中的美丽笔走南极(一)

警告——B-22事件 南极非同寻常的恶劣环境,不时从那里爆出新闻。2002年3月18日,美联社从华盛顿发出一条新闻,引起全世界的关注。消息称,一座相当于新加坡国土面积9倍多的冰山从南极冰架断裂开来。一天后,即3月20日,电视上又反复播放这一画面。只见一座座平面大冰山相互间已经拉开很大的间距,向宽阔的陆缘冰区散去。 南极冰山出现特大松动是美国国家     

站房,生命的依托——笔走南极(八)

南极风大最高每秒可达百米,南极寒冷最低可选零下892摄氏度．南极雪多．遇有阴天随时雪花飘飞。在如此严酷的自然环境下中国南极考察队员要生存要坚持常年考察必须拥有能够依身的站房。可以说把国内的任何建筑模式照搬到南极都是行不通的,不仅影响考察任务的完成．还会对考察队员生命构成威胁。     

南极升起不落的太阳——笔走南极(四)

《草原上升起不落的太阳》、《太阳,太阳永不落》,这些韵律优美、想象丰富、歌颂新生活的歌曲,充满了对太阳的深情和挚爱。但是,在现实生活中,倘若太阳真的没了东起西落,没了昼与夜的交替,时时悬在空中,成了不落的太阳,人们也是难以适应的。经历过南极及昼生活之后,我对此有了深刻的体会。     

冰海观鲸——笔走南极(六)

尽管我国有一万八千多公里长的海岸线,但地球上有史以来最大的动物——鲸,却很少有“擦边”游弋的情况发生。使得国人对这庞然大物的印象,只能散见于电视画面或欧洲某海滩鲸的集体自杀,又或是南美某沿海国家的众多善良人士对搁浅在浅水沙滩的鲸的救助。我原想这辈子见到实物鲸,是不可能了。想不到前些年我乘一艘名为“极地”号的抗冰船在南极冰区航行时,竟然有幸频频与其碰面,留下了难以忘记的印象。     

基于基因组SNPs的南极恩克斯堡岛阿德利企鹅繁殖种群的遗传结构

我国提议在南极恩克斯堡岛新站址北侧3 km的阿德利企鹅(Pygoscelis adeliae)聚集繁殖地建立南极特别保护区, 对保护区边界的划分, 各国尚存争议, 尤其是对南湾(South Bay)的繁殖小种群是否具有遗传独特性, 是否应将其纳入保护区是重点关注的问题。本研究采集了恩克斯堡岛海景湾(Seaview Bay)和南湾的阿德利企鹅样品, 通过全基因组重测序和种群基因组学方法, 分析了恩克斯堡岛不同区域的种群遗传结构。发现恩克斯堡岛海景湾与南湾阿德利企鹅没有显著的遗传分化, 南湾阿德利企鹅不是独特的小种群; 海景湾高海拔区域个体与低海拔区域个体之间也没有显著的遗传差异, 推测该区域阿德利企鹅繁殖群体的分布格局与冰川堆积形成的阶地不具有显著相关性。本工作为恩克斯堡岛保护区和罗斯海新站建设提供了重要科技支撑。     

洪氏环企鹅骨骼的解剖学特点

采用解剖学方法对1只雄性洪氏环企鹅(Spheniscus,humboldti)骨骼系统进行了详细的观察、描述.结果表明:企鹅骨骼结实、沉重不充气;喙长,前端略下弯,颞部呈深凹陷状;肩胛骨及胸骨龙骨突发达;胸椎不愈合;前肢骨骼扁平,特化为鳍状,翼内关节活动性较小,第一掌骨及拇指消失;髌骨发达,跗跖骨短而宽扁.这些特征主要体现了洪氏环企鹅对海中潜水、游泳、取食以及陆地直立的适应.     

Age at first breeding of the African Penguin

Numbers of breeding pairs of African Black Oystercatchers showed a highly significant increase at Cape Agulhas over a 24year study period. Mean numbers of fledglings per pair did not increase correspondingly but showed a cyclic tendency, peaking twice, with a slight overall decline. The increase in the frequency of repeat clutches was close to significant. Nest failures were ascribed largely to human disturbance. Indications of increasing public awareness about the sensitivity of breeding oystercatchers were noted as well as increasing adaptability to human presence among some birds, whereas other birds moved their nests further away from this disturbance. In view of the closure of the Overberg coast to recreational vehicles from 20 February 2002 and the relative importance of the area for the conservation of oystercatchers, this long-term study represents an important baseline against which to measure change.     

Adaptation and Cryptic Pseudogenization in Penguin Toll-Like Receptors

Penguins (Sphenisciformes) are an iconic order of flightless, diving seabirds distributed across a large latitudinal range in the Southern Hemisphere. The extensive area over which penguins are endemic is likely to have fostered variation in pathogen pressure, which in turn will have imposed differential selective pressures on the penguin immune system. At the front line of pathogen detection and response, the Toll-like receptors (TLRs) provide insight into host evolution in the face of microbial challenge. TLRs respond to conserved pathogen-associated molecular patterns and are frequently found to be under positive selection, despite retaining specificity for defined agonist classes. We undertook a comparative immunogenetics analysis of TLRs for all penguin species and found evidence of adaptive evolution that was largely restricted to the cell surface-expressed TLRs, with evidence of positive selection at, or near, key agonist-binding sites in TLR1B, TLR4, and TLR5. Intriguingly, TLR15, which is activated by fungal products, appeared to have been pseudogenized multiple times in the Eudyptes spp., but a full-length form was present as a rare haplotype at the population level. However, in vitro analysis revealed that even the full-length form of Eudyptes TLR15 was nonfunctional, indicating an ancestral cryptic pseudogenization prior to its eventual disruption multiple times in the Eudyptes lineage. This unusual pseudogenization event could provide an insight into immune adaptation to fungal pathogens such as Aspergillus, which is responsible for significant mortality in wild and captive bird populations.     

Proceedings of the 8th Oamaru Penguin Symposium 2012

Abstract

This paper records the abstracts of the presentations given at the 8th Penguin Symposium, held at the Oamaru Opera House, ōamaru, New Zealand, 12 and 13 July 2012.     

四种企鹅叫声特征的比较

2005年2月15日～3月10日使用全方向性麦克风记录了南极地区4种企鹅(王企鹅、长眉企鹅、白眉企鹅和纹颊企鹅)的叫声,分析了其叫声的声谱图和能谱图,比较了不同种企鹅在叫声的持续时间、最高(低)频率和主频等方面的差异。通过比较发现,4种企鹅的叫声存在着明显的种间差异,这使得不同种的企鹅可以从声音上彼此区分开。而无巢企鹅(王企鹅)的声音结构比有巢企鹅(其余3种)更加复杂,这与营无巢生活的习性相符合。     

Penguin heat-retention structures evolved in a greenhouse Earth

Penguins (Sphenisciformes) inhabit some of the most extreme environments on Earth. The 60+ Myr fossil record of penguins spans an interval that witnessed dramatic shifts in Cenozoic ocean temperatures and currents, indicating a long interplay between penguin evolution and environmental change. Perhaps the most celebrated example is the successful Late Cenozoic invasion of glacial environments by crown clade penguins. A major adaptation that allows penguins to forage in cold water is the humeral arterial plexus, a vascular counter-current heat exchanger (CCHE) that limits heat loss through the flipper. Fossil evidence reveals that the humeral plexus arose at least 49 Ma during a 'Greenhouse Earth' interval. The evolution of the CCHE is therefore unrelated to global cooling or development of polar ice sheets, but probably represents an adaptation to foraging in subsurface waters at temperate latitudes. As global climate cooled, the CCHE was key to invasion of thermally more demanding environments associated with Antarctic ice sheets.     

Coalescent Modelling Suggests Recent Secondary-Contact of Cryptic Penguin Species

Molecular genetic analyses present powerful tools for elucidating demographic and biogeographic histories of taxa. Here we present genetic evidence showing a dynamic history for two cryptic lineages within Eudyptula, the world''s smallest penguin. Specifically, we use a suite of genetic markers to reveal that two congeneric taxa (''Australia'' and ''New Zealand'') co-occur in southern New Zealand, with only low levels of hybridization. Coalescent modelling suggests that the Australian little penguin only recently expanded into southern New Zealand. Analyses conducted under time-dependent molecular evolutionary rates lend support to the hypothesis of recent anthropogenic turnover, consistent with shifts detected in several other New Zealand coastal vertebrate taxa. This apparent turnover event highlights the dynamic nature of the region’s coastal ecosystem.     

Proceedings of the 11th Oamaru Penguin Symposium 2018

This paper records the abstracts of the presentations given at the 11th Oamaru Penguin Symposium, held at the Opera House, Oamaru, New Zealand, 3 and 4 May, 2018.     

Diet composition of expanding breeding populations of the Magellanic Penguin

The Magellanic Penguin (Spheniscus magellanicus) is the most abundant and widely distributed seabird breeding on the Patagonian Coast of Argentina. We combined conventional stomach content and stable isotope analysis to assess Magellanic Penguin diet during the chick rearing stage at the two northernmost colonies in an area subject to fisheries. In 2011 and 2013, Thornfish (Bovichtus argentinus) was the main prey by mass at Complejo Islote Lobos (63.0% and 32.3%, respectively) and Argentine Anchovy (Engraulis anchoita) at Estancia San Lorenzo (85.2 and 63.3%, respectively). Magellanic Penguins from both colonies showed low isotopic niche overlap in 2011 (36%) and no overlap in 2013, suggesting a different use of prey species and/or foraging areas. Stable isotope mixing models showed that Argentine Anchovy (52.8%) and Thornfish (65.9%) were the main prey at Complejo Islote Lobos in 2011 and 2013, respectively, while Patagonian Redfish (Sebastes oculatus) (46.4%) and Squat Lobster (Munida gregaria) (50%) were the main prey at Estancia San Lorenzo in 2011 and 2013, respectively. Results show that in addition to Argentine Anchovy, previously recognized as main prey for breeding Magellanic Penguins in northern Patagonia, other juvenile or small sized fish are important diet items. Diet results suggest different scenarios of food conditions for each colony, despite the relative short distance between breeding locations. The low contribution of Argentine Hake (Merluccius hubbsi) and Argentine Shortfin Squid (Illex argentinus) suggests a low trophic overlap with commercial fisheries. The information provided is key to understand changes in the marine ecosystem and potential penguin-fishery interactions.