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1.
OLOF OLSSON  A. W. NORTH 《Ibis》1997,139(3):504-512
King Penguins Aptenodytes patagonicus which were rearing chicks were studied during three summers from November 1991 to March 1994 at South Georgia. Stomach samples ( n =115) collected by flushing had a mean mass of 1308 g. Fish mass was allocated to each species based on the relationship between fish mass and otolith length. Three mesopelagic lanternfishes (Myctophidae), Krefftichthys anderssoni, Electrona carlsbergi and Protomyctophum choriodon , dominated the diet both by numbers and mass. They were small fish with mean mass of 3–7 g. Overall, K. anderssoni dominated the diet in terms of numbers and mass. Although Barracudina Notolepis coatsi occurred in <3% of the diet by numbers, it was large (106 g) and was second most important in terms of mass. Squid represented <3% of the diet by mass. Although the chick-rearing success was poor in the 1993–1994 summer, meal size was not reduced but foraging trips were longer. In the 1993–1994 summer, a larger proportion of the otoliths were not identifiable because they were more completely digested. Fewer otoliths were identified as being those of K. anderssoni , but we argue that about 90% of the unidentified otoliths were K. anderssoni. There was also more squid and N. coatsi in the diet during the poor summer. A consistent trend was that P. choriodon was rare or absent in early summer but more important later in the year, and at the end of 1992–1993, it was the dominant prey. We conclude that myctophid fish, especially K. anderssoni , are the main summer prey of King Penguins rearing chicks at South Georgia, as found in other recent studies in the Southern Ocean.  相似文献   
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We used morphological, vocal and molecular (one mitochondrial and two nuclear loci) data to re-evaluate the taxonomic status of the taxa acanthizoides , concolor , and brunnescens in the Cettia acanthizoides (J. Verreaux, 1871) complex. We conclude that all three are valid taxa, and that acanthizoides of China and concolor of Taiwan are best treated as conspecific, whereas brunnescens of the Himalayas is better considered as a separate species. The degree of morphological, vocal, and genetic differentiation is variably congruent among all taxa; the recently separated acanthizoides and concolor differ slightly in plumage and structure but are indistinguishable in vocalizations, whereas the earlier diverged brunnescens and acanthizoides/concolor differ only slightly more in morphology but to a much greater degree in vocalizations. We stress the essential nature of taxonomic revisions as a prerequisite for the biodiversity estimates required for conservation planning.  © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society , 2007, 149 , 437–452.  相似文献   
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The timing of birth is often correlated with offspring fitness in animals, but experimental studies that disentangle direct effects of parturition date and indirect effects mediated via variation in female traits are rare. In viviparous ectotherms, parturition date is largely driven by female thermal conditions, particularly maternal basking strategies. Our field and laboratory studies of a viviparous lizard (Niveoscincus ocellatus) show that earlier‐born offspring are more likely to survive through their first winter and are larger following that winter, than are later‐born conspecifics. Thus, the association between parturition date and offspring fitness is causal, rather than reflecting an underlying correlation between parturition date and maternal attributes. Survival selection on offspring confers a significant advantage for increased maternal basking in this species, mediated through fitness advantages of earlier parturition. We discuss the roles of environmentally imposed constraints and parent–offspring conflict in the evolution of maternal effects on parturition date.  相似文献   
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A new species of Phylloscopus warbler, which we name Phylloscopus calciatilis Limestone Leaf Warbler, is described from central and northern Vietnam and central and northern Laos; it probably also breeds in southernmost China. In morphology, the new species is very similar to Sulphur-breasted Warbler Phylloscopus ricketti , but it is smaller with a proportionately larger bill and rounder wing. Its song and calls are diagnostic. Based on mitochondrial and nuclear DNA, the new species is most closely related to P. ricketti and Yellow-vented Warbler Phylloscopus cantator , and it is inferred to be sister to the latter. The mitochondrial divergences between these three species are at the low end of the variation found in other species of Phylloscopus and Seicercus warblers, but greater than in other taxa generally treated as subspecies. Possible introgressive hybridization between the new species and P. ricketti is discussed, but more data are needed to establish whether it does occur and, if it does, to what extent. The new species appears to have a restricted breeding range in limestone karst environments, where it is locally common and therefore not under any immediate threat. In view of the recognition of the new species, all previous records of P. ricketti sensu lato need to be re-evaluated.  相似文献   
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The higher‐level phylogeny of the order Hemiptera remains a contentious topic in insect systematics. The controversy is chiefly centred on the unresolved question of whether or not the hemipteran suborder Auchenorrhyncha (including the extant superfamilies Fulgoroidea, Membracoidea, Cicadoidea and Cercopoidea) is a monophyletic lineage. Presented here are the results of a multilocus molecular phylogenetic investigation of relationships among the major hemipteran lineages, designed specifically to address the question of Auchenorrhyncha monophyly in the context of broad taxonomic sampling across Hemiptera. Phylogenetic analyses (maximum parsimony, maximum likelihood and Bayesian inference) were based on DNA nucleotide sequence data from seven gene regions (18S rDNA, 28S rDNA, histone H3, histone 2A, wingless, cytochrome c oxidase I and NADH dehydrogenase subunit 4) generated from 86 in‐group exemplars representing all major lineages of Hemiptera (plus seven out‐group taxa). All combined analyses of these data recover the monophyly of Auchenorrhyncha, and also support the monophyly of each of the following lineages: Hemiptera, Sternorrhyncha, Heteropterodea, Heteroptera, Fulgoroidea, Cicadomorpha, Membracoidea, Cercopoidea and Cicadoidea. Also presented is a review of the major lines of morphological and molecular evidence for and against the monophyly of Auchenorrhyncha.  相似文献   
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1. We assessed the role of cyanobacterial–bacterial consortia (Gloeotrichia echinulata phycospheres) for net changes in inorganic carbon, primary production (PP) and secondary production in Lake Erken (Sweden). 2. At the time of sampling, large colonies of G. echinulata formed a massive bloom with abundances ranging from 102 colonies L?1 in the pelagic zone to 5000 colonies L?1 in shallow bays. These colonies and their surrounding phycospheres contributed between 17 and 92% of total PP, and phycosphere‐associated bacteria contributed between 8.5 and 82% of total bacterial secondary production. PP followed a diurnal cycle, whereas bacterial production showed no such pattern. Over a 24 h period, carbon dioxide measurements showed that the phycospheres were net autotrophic in the top layer of the water column, whereas they were net heterotrophic below 2 m depth. 3. Sequencing and phylogenetic analysis of 16S rRNA genes of attached bacteria revealed a diverse bacterial community that included populations affiliated with Proteobacteria, Bacteriodetes, Acidobacteria, Fusobacteria, Firmicutes, Verrucomicrobia, and other Cyanobacteria. 4. Compared with their planktonic counterparts, bacteria associated with cyanobacterial phycospheres had lower affinity for arginine, used as a model compound to assess uptake of organic compounds. 5. Extrapolation of our data to the water column of lake Erken suggests that microorganisms that were not associated with cyanobacteria dominated CO2 production at the ecosystem scale during our experiments, as CO2 fixation balanced CO2 production in the cyanobacterial phycospheres.  相似文献   
10.
M. HEALEY  M. OLSSON 《Austral ecology》2008,33(8):1015-1021
Males of the colour polymorphic Australian painted dragon lizard Ctenophorus pictus occur in red or yellow head colouration. In a previous experiment, we showed that red is associated with a higher probability of winning staged contests for resources (females or space) and that manipulation of male colouration by painting males in the opposing morph changed the dynamics of staged interactions by prolonging them 30‐fold. Thus, colour is linked to behavioural differences between males and is involved in information transfer between competing males. This inherent red dominance could result in yellow males being marginalized to poorer quality territories in terms of access to females, food, perch sites or shade. With an experiment in the wild, we test to what extent this prediction is upheld, and how colour manipulation affects morph‐specific success in territory acquisition when male body size, territory quality and emergence time from hibernation are controlled through manipulation or randomization. There was no significant effect of colour category per se, although on average red males remained closer to the release sites (our proxy for territory acquisition ability) than yellow males and artificially altered morphs moved the furthest away. There was a significant interaction effect between colour category and experimental release position, which may be linked to differences in how exposed (or not) these positions were and morph‐specific ability to cope with such exposure (e.g. ‘boldness’). Our data show that territory acquisition success is not merely a function of competitive ability but a composite outcome of a suite of factors, including signal perception.  相似文献   
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