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1.
Management of harvested species is of great importance in order to maintain a sustainable population. Genetics is, however, largely neglected in management plans. Here, we analysed the genetics of the bean goose (Anser fabalis) in order to aid conservation actions for the commonly hunted but declining subspecies, the taiga bean goose (A. f. fabalis). We used mitochondrial DNA (mtDNA) and microsatellites to determine the subspecies composition of the Finnish bean goose harvest, as the hunting bag is thought to comprise two subspecies, the taiga bean goose and the tundra bean goose (A. f. rossicus). The latter subspecies has a more stable or even increasing population size. Other eastern subspecies (A. f. serrirostris, A. f. middendorffii) could additionally be part of the Finnish hunting bag. We estimated genetic diversity, genetic structure and sex-biased gene flow of the different subspecies. Most of the harvested bean geese belonged to the taiga bean goose, whereas most of the tundra bean goose harvest was found to be geographically restricted to south-eastern Finland. The mtDNA data supported strong genetic structure, while microsatellites showed much weaker structuring. This is probably due to the extreme female philopatry of the species. The taiga bean goose had lowered genetic diversity compared to other subspecies, warranting management actions. We also detected A. f. serrirostris mtDNA haplotypes and evidence of interspecific hybridization with two other Anser species.  相似文献   

2.
We analysed barnacle Branta leucopsis and pink-footed goose Anser brachyrhynchus summer diets (May–July 2003) based on the proportions of different plant constituents in the faecal material of adult breeding birds in Sassendalen, Svalbard to assess potential inter-specific competition. Diets were highly restricted and overlapped little during pre-nesting and post hatch. During incubation both species showed greatest variety in their diet, reflecting site-specific differences in local food abundance. However, locally the diets of pink-footed and barnacle geese resembled each other most at this time (although still differing significantly). The conflicting needs of nest defence and maintenance of body condition constrains the extent of the feeding resource utilised by nesting pairs and explains slightly greater dietary overlap at this time. Hence, there is little evidence of inter-specific competition (interference or depletion) at present, but this is most likely to be manifest during the incubation period in the future if goose numbers continue to increase. More detailed investigations of the degree of spatial overlap of the two species and their effects on plant structure, quality and community composition are necessary to predict likely outcomes of expected increases in numbers of both goose species.  相似文献   

3.
The phylogenetic relationships of seven goose species and two of the subspecies representing the genus Anser were studied by approximately 1180 bp of mitochondrial DNA tRNAglu, control region and tRNAphe sequences. Despite obvious morphological and behavioural affinities among the species, their evolutionary relationships have not been studied previously. The small amount of genetic differentiation observed in the mitochondrial DNA indicates an extremely close evolutionary relationship between the Anser species. The sequence divergences between the species (0.9–5.5%) are among the lowest reported for avian species with speciation events of Anser geese dating to late Pliocene and Pleistocene. The species grouped into four mtDNA lineages: (1) snow and Ross’ goose, (2) greylag goose, (3) white‐fronted goose, and (4) bean, pink‐footed and lesser white‐fronted goose. The phylogenetic relationships of the most closely related species, bean, pink‐footed and lesser white‐fronted goose, indicate a period of rapid cladogenesis. The poor agreement between morphological relationships and the phylogenetic relationships indicated by mtDNA sequences implies that either ancestral polymorphism and lineage sorting, hybridization and introgression or convergent evolution has been involved.  相似文献   

4.
In the high-arctic archipelago of Svalbard, the pink-footed goose (Anser brachyrhynchus) population has increased dramatically over the last decades. The population increase and the corresponding range expansion suggest a substantial increase in the potential for disturbance of the tundra caused by goose herbivory. In this study, we used surveys of pink-footed goose grubbing from two separate years (2007 and 2012) to examine the temporal changes in the prevalence of grubbing in central Spitsbergen. During this time period, the Svalbard-breeding pink-footed goose population had increased from 56,400 to 80,000 individuals. We compared grubbing prevalence between the 2 years, standardising the comparison by using a published model of habitat suitability for grubbing (Speed et al. in Ecosystems 12:349-359, 2009) as a covariate. Habitat suitability was a significant predictor of grubbing prevalence across both years, with higher grubbing probability in habitats predicted to be more suitable for grubbing. The probability of grubbing was on average 4 times higher in 2012 than in 2007. In 2007, all tundra habitats had a probability of <27 % of being grubbed whilst in 2012, there was a probability for being grubbed of more than 34 % in the least suitable habitat and around 59 % in the most suitable habitat. The increase in grubbing prevalence demonstrates a great need for monitoring the expanding pink-footed goose population and its impact on the tundra landscape.  相似文献   

5.
Population structure and phylogeography of the pink-footed goose, Anser brachyrhynchus Baillon 1833, was studied using mtDNA control region sequences (221 bp) from 142 individuals. Present breeding areas of the species in Greenland, Iceland, and Svalbard were largely covered by ice during the late Pleistocene. In pairwise comparisons phiST estimates showed significant differentiation among eastern and western populations, whereas sampling localities within both areas were not differentiated. The mtDNA data indicate that the populations have separated recently (less than 10 000 years ago) and present breeding areas were colonized from one refugial population. The levels of haplotype and nucleotide diversity were approximately five times higher for the eastern population compared to the western population and suggest that the latter was colonized by a subset of eastern birds. Time to the most recent common ancestor of the species is 32 000-46 000 years, i.e. the present mtDNA variation of the pink-footed goose has accumulated during the last 0.1 My. Estimates of the long-term female effective population size (5400-7700 for the eastern population) imply that the refugial population of the pink-footed goose has been large. Tundra habitats were more extensive in cold periods of the late Pleistocene than today and may have sustained population sizes that allowed the accumulation of extant genetic polymorphism. It is not probable that the postulated small refugial areas in the high latitudes had a significant role in maintaining this diversity.  相似文献   

6.
A high proportion of the global soil carbon stock is stored in tundra soils. However, populations of arctic-breeding migratory geese including pink-footed geese, Anser brachyrhynchus, are increasing due to agricultural changes and conservation measures in their wintering grounds. Foraging by these geese, which is widespread in extent, reduces the quantity of carbon stored in arctic tundra ecosystems. Here, the potential carbon loss caused by foraging pink-footed geese is modelled across the high-arctic archipelago of Svalbard, combining field experiments, habitat maps and published spatial models of foraging. The carbon loss caused by foraging geese was estimated three growing seasons following perturbation allowing for some recovery to take place. The carbon loss caused by 1-year worth of grubbing was estimated to be 1,700 tonnes, or 37 kg per goose. A total of over 340,000 tonnes of carbon could be affected given an unlimited increase in goose population. Estimated losses were mostly from wetter habitats, which are both carbon rich and highly selected for by foraging geese. The across-landscape carbon loss caused by geese is not great in magnitude in comparison to expected climate-driven carbon losses; however, it is locally severe, and demonstrates how migratory connectivity links processes, such as agricultural change and conservation measures in temperate Europe with carbon dynamics in the high arctic.  相似文献   

7.
Using RAPD PCR analysis and sequencing of the 5′ end segment of the mtDNA control region, the genetic diversity and differentiation of Far Eastern populations of greater white-fronted goose Anser albifrons Scopoli, 1769 and bean goose Anser fabalis Latham, 1787 were examined. Based on RAPD PCR data, the level of gene diversity (h) for A. albifrons (0.3634) and A. fabalis (0.3899) was calculated. Sequence data showed considerably higher level of inter-population diversity in A. fabalis (26.4%), compared to A. albifrons (1.88%). Similarly, the nucleotide and haplotype diversity parameters were somewhat higher in A. fabalis (0.01852 and 0.955). Phylogenetic reconstructions generated using neighbor-joining and maximum parsimony algorithms divided each of the examined species into two clusters that differ in the number of haplotypes included. These clusters can correspond to the subspecies that live in the Far East.  相似文献   

8.
The pattern of phenotypic and molecular variation within the polytypic olivaceous warbler H. pallida was examined. This species is distributed in the southern parts of the western Palaearctic, central Asia and in the arid parts of northern Africa, and also in parts of the sub-Saharan Sahel zone. Based on morphology, five subspecies, at times assigned to three groups, have been identified. By comparing morphological, behavioural, vocal and molecular variation, we investigated the phenotypic and phylogenetic relationships within the Hippolais pallida group. The morphological and genetic data of the present study support the view of splitting the olivaceous warbler into a western (former subspecies opaca) and an eastern form (former subspecies elaeica, pallida, reiseri and laeneni). Opaca is consistently and significantly larger than the other taxa in all size measurements, even if it does share morphological properties with elaeica in characters associated with migration. The song of the polytypic pallida differs clearly from that of opaca, and is remarkably consistent within its wide range which comprises four subspecies. The molecular analysis, and the resulting phylogenetic pattern, clearly separated opaca on a single branch distant from the other subspecies. The eastern form consists of two non-overlapping haplotype groups: elaeica with relatively diverse mtDNA variation, and the three African subspecies pallida, reiseri and laeneni, which all share the same or closely related mtDNA haplotypes. It remains open whether the African taxa should be regarded as three valid subspecies of the Eastern olivaceous warbler, or if they are better treated as a single African subspecies.  相似文献   

9.
Traditional subspecies classifications may suggest phylogenetic relationships that are discordant with evolutionary history and mislead evolutionary inference. To more accurately describe evolutionary relationships and inform conservation efforts, we investigated the genetic relationships and demographic histories of Buteo lineatus subspecies in eastern and western North America using 21 nuclear microsatellite loci and 375-base pairs of mitochondrial control region sequence. Frequency based analyses of mitochondrial sequence data support significant population distinction between eastern (B. l. lineatus/alleni/texanus) and western (B. l. elegans) subspecies of B. lineatus. This distinction was further supported by frequency and Bayesian analyses of the microsatellite data. We found evidence of differing demographic histories between regions; among eastern sites, mitochondrial data suggested that rapid population expansion occurred following the end of the last glacial maximum, with B. l. texanus population expansion preceding that of B. l. lineatus/alleni. No evidence of post-glacial population expansion was detected among western samples (B. l. elegans). Rather, microsatellite data suggest that the western population has experienced a recent bottleneck, presumably associated with extensive anthropogenic habitat loss during the 19th and 20th centuries. Our data indicate that eastern and western populations of B. lineatus are genetically distinct lineages, have experienced very different demographic histories, and suggest management as separate conservation units may be warranted.  相似文献   

10.
Herbivory can lead to shifts in ecosystem state or changes in ecosystem functioning, and recovery from herbivory is particularly slow in disturbance-sensitive ecosystems such as arctic tundra. Herbivore impacts on ecosystems are variable in space and time due to population fluctuations and selective utilization of habitats; thus there is a need to accurately predict herbivore impacts at the landscape scale. The habitat utilization and extent of disturbance caused by increasing populations of pink-footed geese (Anser brachyrhynchus) foraging in the high arctic tundra of Svalbard were assessed using a predictive model of the population’s habitat use. Pink-footed geese arrive in Svalbard in early spring when they forage for belowground plant parts; this foraging (called grubbing) can cause vegetation loss and soil disturbance. Surveys of the extent and intensity of grubbing were carried out to develop predictive models that were subsequently tested against data collected during the following year from different areas. Both habitat type at a particular point and the amount of preferred fen habitat in the surrounding area were powerful predictors of grubbing likelihood and the developed model correctly classified over 69% of validation observations with an AUC of 0.75. Pink-footed geese showed a strong preference for wetter habitats within low-lying landscapes. Extrapolation of the predictive model across the archipelago showed that a maximum potential area of 2300 km2 (3.8% of the archipelago) could be disturbed by grubbing. Thus, increasing populations of geese may cause large-scale vegetation loss and soil disturbance in arctic ecosystems.  相似文献   

11.
The subalpine warbler Sylvia cantillans is formally considered a polytypic species, with four subspecies, European S. c. cantillans, albistriata, moltonii (recently resumed name: subalpina) and North African S. c. inornata. They are very similar in external morphology but clearly differ in their vocalizations. We evaluated their uncertain taxonomic status reconstructing the phylogenetic and phylogeographic relationships among populations sampled across major biogeographical areas in the European species’ range, using nucleotide sequences of the mitochondrial cytochrome b gene (mtDNA cyt b). A variety of phylogenetic analyses concordantly led to identify four major groups, only partially corresponding to the three European nominal subspecies. Phylogenetic trees showed a monophyletic group including all moltonii individuals, well diverged from all other taxa. Populations taxonomically assigned to cantillans were polyphyletic being split into two distinct clades (western and southern cantillans), with monophyletic albistriata closely related to southern cantillans. Individuals of moltonii and southern cantillans sampled in sites of sympatry in central Italy were assigned to their respective groups, with perfect concordance between phenotypic and genetic identifications. All findings indicate that moltonii should be ranked as a distinct species. Former subspecies cantillans is polyphyletic, but additional data are needed to define the taxonomic status of its two clades. Albistriata is phylogenetically related to southern cantillans and should be provisionally kept as a subspecies of S. cantillans. The cantillans complex thus provides an interesting case-study illustrating geographical structuring across small geographical ranges, and it exemplifies speciation through differentiation in allopatry leading to reproductive isolation after a secondary contact.  相似文献   

12.
The origins of the European domestic goose are uncertain. The available information comes from archaeological findings and historical literature, but genetic evidence has hitherto been scarce. The domestic goose in Europe is derived from the greylag goose (Anser anser), but it is not known where the initial domestication took place and which of the two subspecies of greylag goose was ancestral. We aimed to determine the amount and geographical distribution of genetic diversity in modern populations of greylag geese as well as in different breeds of the domestic goose to make inferences about goose domestication. We studied DNA sequence variation in the mitochondrial control region of greylag geese from multiple populations across Europe and western Asia as well as specimens of domestic geese representing 18 modern breeds and individuals not belonging to any recognised breed. Our results show notable differences in genetic diversity between different greylag goose populations and the presence of six mitochondrial haplogroups which show a degree of geographical partitioning. The genetic diversity of the domestic goose is low, with 84% of sampled individuals having one of two major closely related haplotypes, suggesting that modern European domestic geese may derive from a narrow genetic base. The site of domestication remains unresolved, but domestic geese in Turkey were unusually diverse, indicating the importance of further sampling in the vicinity of the eastern Mediterranean and the Near East. There appears to be past or ongoing hybridisation between greylags and domestic geese in particular areas, consistent with field observations.  相似文献   

13.
The major physiognomic and ecological categories of the lichen-rich, epigeic communities in the boreal (taiga) and arctic (tundra) zones are defined and their syntaxonomy and ecology in Europe, Asia and North America is reviewed. In the boreal and hemiarctic areas open, dry, acidophytic lichen woodlands are widespread, especially on sandy habitats. Their epigeic lichen synusiae are usually dominated by four fruticoseCladina species, being extremely homogeneous in species composition and structure throughout the boreal zone, while the dominant trees and the other vascular plant flora of the woodlands are geographically more variable. No phytosociological classification system exists that would cover most of these communities over the circumpolar regions. Very similar communities, though much more poorly known, are found on thin soils over Precambrian rock outcrops. Other sites to produce epigeic lichen communities include open sand dunes, treeless heathlands, drier bogs and many seral stages, like those on road banks. Boreal lichen-rich communities on eutrophic soils may be developed in semiarid regions, in particular. In the Arctic, lichens are common in most communities, and the driest ones are regularly lichen-dominated, whether acidophytic or eutrophytic, chionophytic or achionophytic. Detailed syntaxonomic systems for their classification have been developed, especially in Greenland and Scandinavian mountains (in oroarctic zones in the latter regions). The richest fruticose lichen areas are in continental, hemiarctic timberline regions in northern Siberia and Canada. The southern and middle arctic subzones are also characterized by many macrolichens, such asCetraria cucullata, C. nivalis, Alectoria ochroleuca, andThamnolia vermicularis, but everywhere also small, crustose lichens are common on soil, such asRinodina turfacea andLopadium pezizoideum, which are often overlooked in vegetation analyses. The presence of microlichens and the formation of mosaic micropatterns of soil lichen communities is particularly typical of the northern arctic subzone. The conservation problems of the boreal and arctic lichen communities include overgrazing by reindeer or caribou, which has caused delichenization in some regions, extensive forest and tundra fires, use of heavy transport vehicles in forestry and tundra operations, and, locally, heavy industrial air pollution.  相似文献   

14.
The lesser white-fronted goose (Anser erythropus) isthe most threatened of the Palearctic goose species with a decliningpopulation trend throughout its distributional range. The currentestimate of the Fennoscandian subpopulation size is 30–50 breedingpairs, whereas it still numbered more than 10000 individuals at thebeginning of the last century. Reintroduction and restocking have beencarried out in Sweden and Finland using captive lesser white-frontedgoose stock with unknown origins. We have carried out a study of thegenetic composition of captive-bred stock by sequencing a 221 bphypervariable fragment of the mitochondrial DNA (mtDNA) control regionfrom 15 individuals from the Hailuoto farm, Finland. Two out of thethree maternal lineages detected in the captive stock are also presentin wild populations. The third maternal lineage among the captive lesserwhite-fronted geese originates from the closely related greaterwhite-fronted goose (Anser albifrons). None of the investigatedwild lesser white-fronted goose individuals carried the mtDNA of thegreater white-fronted goose. The presence of greater white-fronted goosemtDNA in the lesser white-fronted goose captive stock suggests thathybridization has occurred during captive propagation.  相似文献   

15.
Sun M  Shen X  Liu H  Liu X  Wu Z  Liu B 《Marine Genomics》2011,4(3):159-165
Mitochondrial genomes play a significant role in the reconstruction of phylogenetic relationships within metazoans. There are still many controversies concerning the phylogenetic position of the phylum Bryozoa. In this research, we have finished the complete mitochondrial genome of one bryozoan (Tubulipora flabellaris), which is the first representative from the class Stenolaemata. The complete mitochondrial genome of T. flabellaris is 13,763 bp in length and contains 36 genes, which lacks the atp8 gene in contrast to the typical metazoan mitochondrial genomes. Gene arrangement comparisons indicate that the mitochondrial genome of T. flabellaris has unique gene order when compared with other metazoans. The four known bryozoans complete mitochondrial genomes also have very different gene arrangements, indicates that bryozoan mitochondrial genomes have experienced drastic rearrangements. To investigate the phylogenetic relationship of Bryozoa, phylogenetic analyses based on amino acid sequences of 11 protein coding genes (excluding atp6 and atp8) from 26 metazoan complete mitochondrial genomes were made utilizing Maximum Likelihood (ML) and Bayesian methods, respectively. The results indicate the monopoly of Lophotrochozoa and a close relationship between Chaetognatha and Bryozoa. However, more evidences are needed to clarify the relationship between two groups. Lophophorate appeared to be polyphyletic according to our analyses. Meanwhile, neither analysis supports close relationship between Branchiopod and Phoronida. Four bryozoans form a clade and the relationship among them is T. flabellaris + (F. hispida + (B. neritina + W. subtorquata)), which is in coincidence with traditional classification system.  相似文献   

16.
East Asian migratory waterfowl have greatly declined since the 1950s, especially the populations that winter in China. Conservation is severely hampered by the lack of primary information about migration patterns and stopover sites. This study utilizes satellite tracking techniques and advanced spatial analyses to investigate spring migration of the greater white‐fronted goose (Anser albifrons) and tundra bean goose (Anser serrirostris) wintering along the Yangtze River Floodplain. Based on 24 tracks obtained from 21 individuals during the spring of 2015 and 2016, we found that the Northeast China Plain is far‐out the most intensively used stopover site during migration, with geese staying for over 1 month. This region has also been intensely developed for agriculture, suggesting a causal link to the decline in East Asian waterfowl wintering in China. The protection of waterbodies used as roosting area, especially those surrounded by intensive foraging land, is critical for waterfowl survival. Over 90% of the core area used during spring migration is not protected. We suggest that future ground surveys should target these areas to confirm their relevance for migratory waterfowl at the population level, and core roosting area at critical spring‐staging sites should be integrated in the network of protected areas along the flyway. Moreover, the potential bird–human conflict in core stopover area needs to be further studied. Our study illustrates how satellite tracking combined with spatial analyses can provide crucial insights necessary to improve the conservation of declining Migratory species.  相似文献   

17.
Recently, other researchers have found that closely related primate species had a lower male-to-female mutation rate ratio (α) than distantly related species. To determine if this is a general phenomenon affecting other mammalian orders, eleven species or subspecies of the rodent genus Mus and two outgroup species were compared. Intron sequences from a gene in the nonrecombining region of the Y chromosome Jarid1d (Smcy) and its X chromosomal gametolog, Jarid1c (Smcx), were analyzed in a phylogenetic context. The male-to-female mutation rate ratio for all thirteen taxa is approximately 2.5, which is similar to previous estimates in more distantly related rodents. However, when branches with lengths of more than 2.5% were removed from the analysis, the male-to-female mutation rate ratio dropped to 0.9. Thus, in closely related rodents, as in closely related primates, the male-to-female mutation rate ratio is lower than expected. [Reviewing Editor: Dr. Deborah Charlesworth] An erratum to this article is available at.  相似文献   

18.
Numerous studies have shown that large, herbivorous waterfowl can reduce quantity of aquatic plants during the breeding or wintering season, but relatively few document herbivory effects at staging areas. This study was done to determine if feeding activities of tundra swans (Cygnus columbianus columbianus) and Canada geese (Branta canadensis) had a measurable additive influence on the amount of aquatic plants, primarily muskgrass (Chara vulgaris), wild celery (Vallisneria americana), and sago pondweed (Potamogeton pectinatus), removed during the fall migration period at Long Point, Lake Erie, Ontario. Exclosure experiments done in fall 1998 and 1999 showed that, as compared to ducks and abiotic factors, these two large herbivorous waterfowl did not have any additional impact on above or below ground biomass of those aquatic plants. As expected, however, there were substantial seasonal reductions in above-ground and below-ground biomass of aquatic plants in wetlands that were heavily used by all waterfowl. We suggest that differences in large- and small-scale habitat use, feeding activity, and food preferences between tundra swans and other smaller waterfowl as well as compensatory herbivory contributed to our main finding that large waterfowl did not increase fall reductions of Chara spp, V. Americana, and P. pectinatus biomass.  相似文献   

19.
Dispersal and migratory behavior are influential factors in determining how genetic diversity is distributed across the landscape. In migratory species, genetic structure can be promoted via several mechanisms including fidelity to distinct migratory routes. Particularly within North America, waterfowl management units have been delineated according to distinct longitudinal migratory flyways supported by banding data and other direct evidence. The greater white‐fronted goose (Anser albifrons) is a migratory waterfowl species with a largely circumpolar distribution consisting of up to six subspecies roughly corresponding to phenotypic variation. We examined the rangewide population genetic structure of greater white‐fronted geese using mtDNA control region sequence data and microsatellite loci from 23 locales across North America and Eurasia. We found significant differentiation in mtDNA between sampling locales with flyway delineation explaining a significant portion of the observed genetic variation (~12%). This is concordant with band recovery data which shows little interflyway or intercontinental movements. However, microsatellite loci revealed little genetic structure suggesting a panmictic population across most of the Arctic. As with many high‐latitude species, Beringia appears to have played a role in the diversification of this species. A common Beringian origin of North America and Asian populations and a recent divergence could at least partly explain the general lack of structure at nuclear markers. Further, our results do not provide strong support for the various taxonomic proposals for this species except for supporting the distinctness of two isolated breeding populations within Cook Inlet, Alaska (A. a. elgasi) and Greenland (A. a. flavirostris), consistent with their subspecies status.  相似文献   

20.
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