Wild hybrids of Lesser White-fronted Goose (Anser erythropus)×Greater White-fronted Goose (A. albifrons) (Aves: Anseriformes) from the European migratory flyway

The Lesser White-fronted Goose [Anser erythropus (Linnaeus, 1758)] is one of the most threatened Palearctic goose species, with the Fennoscandinavian subpopulation in particular having seen a drastic decline over the last century. In the 1990s, captive-bred Lesser White-fronted Geese were used successfully for reintroduction and restocking in Sweden and Finland. The discovery of Greater White-fronted Goose [Anser albifrons (Scopoli, 1769)] mtDNA haplotypes in some of these captive-bred birds (Ruokonen et al. 2000) suggested that hybridisation had occurred during captive propagation and led to the discontinuation of the release of captive goslings. Here we report two hybrids of Lesser×Greater White-fronted Geese that were collected on their wintering grounds in England in 1936 and Holland in 1966. Birds from western Russia normally do not migrate south to Western Europe. Hence, these birds most likely originated from the Fennoscandinavian subpopulation and were collected prior to the commencement of the captive-breeding programmes. Both specimens show a heterogeneous set of morphological characters, some of which shared with the putative parent species and others being intermediate between the two White-fronted Goose species. A Canonical Discriminant Function analysis positions both specimens between the two putative parent species, making their hybrid status likely. We show, thus, that hybridisation between Greater and Lesser White-fronted Geese does occur naturally, albeit perhaps infrequently, and argue that the presence of Greater White-fronted Goose mtDNA haplotypes in Lesser White-fronted Goose may be the result of this naturally occurring hybridisation. Our data provide additional information on the debate whether the restocking programmes were halted for the right reasons and whether it is desirable to re-commence with the reintroduction programme.     

长江中下游湿地大型水鸟种群动态和幼鸟比例研究

迁徙水鸟保护对生物多样性保护具有重要意义。开展水鸟种群数量和幼鸟比例监测,对科学评估其种群变化趋势、制定长期保护策略具有重要价值。长江中下游湿地是东亚-澳大利西亚迁徙路线上重要的水鸟越冬区之一。本研究采用野外同步调查等方法对该区域87个湿地的亟需保护和具有代表性的10种大型越冬水鸟,其中雁形目6种,分别是鸿雁Anser cygnoides、豆雁A.fabalis、灰雁A.grus、白额雁A.albifrons、小白额雁A.erythropus和小天鹅Cygnus columbianus;鹤形目4种,分别是白鹤Leucogeranus leucogeranus、白枕鹤Antigone vipio、灰鹤Grus grus和白头鹤G.monacha,进行了长期监测(2003—2019年冬季),并结合相关文献,评估其种群变化趋势、幼鸟比例和死亡率。研究结果如下：(1)2005—2019年3种水鸟(豆雁、灰雁和灰鹤)的种群数量呈上升趋势,7种水鸟(鸿雁、白额雁、小白额雁、小天鹅、白鹤、白枕鹤和白头鹤)种群数量呈下降趋势;(2)种群趋势下降组(N=7)和上升组(N=3)的幼鸟比例均值在2016—2...     

Wild hybrids of Lesser White-fronted Goose (Anser erythropus)×Greater White-fronted Goose (A. albifrons) (Aves: Anseriformes) from the European migratory flyway

The Lesser White-fronted Goose [Anser erythropus (Linnaeus, 1758)] is one of the most threatened Palearctic goose species, with the Fennoscandinavian subpopulation in particular having seen a drastic decline over the last century. In the 1990s, captive-bred Lesser White-fronted Geese were used successfully for reintroduction and restocking in Sweden and Finland. The discovery of Greater White-fronted Goose [Anser albifrons (Scopoli, 1769)] mtDNA haplotypes in some of these captive-bred birds (Ruokonen et al. 2000) suggested that hybridisation had occurred during captive propagation and led to the discontinuation of the release of captive goslings. Here we report two hybrids of Lesser×Greater White-fronted Geese that were collected on their wintering grounds in England in 1936 and Holland in 1966. Birds from western Russia normally do not migrate south to Western Europe. Hence, these birds most likely originated from the Fennoscandinavian subpopulation and were collected prior to the commencement of the captive-breeding programmes. Both specimens show a heterogeneous set of morphological characters, some of which shared with the putative parent species and others being intermediate between the two White-fronted Goose species. A Canonical Discriminant Function analysis positions both specimens between the two putative parent species, making their hybrid status likely. We show, thus, that hybridisation between Greater and Lesser White-fronted Geese does occur naturally, albeit perhaps infrequently, and argue that the presence of Greater White-fronted Goose mtDNA haplotypes in Lesser White-fronted Goose may be the result of this naturally occurring hybridisation. Our data provide additional information on the debate whether the restocking programmes were halted for the right reasons and whether it is desirable to re-commence with the reintroduction programme.     

Barnacle Goose (Branta leucopsis) feeding ecology and trophic relationships on Kolguev Island: The usage patterns of nutritional resources in tundra and seashore habitats

Insight into colonization of new areas by invasive species and their relationships with aboriginal species is a major challenge in ecology, allowing for prediction of the outcome of biological invasions. In this context, the current expansion of the Barnacle Goose (Branta leucopsis) is of great interest. The seasonal dynamics of Barnacle Goose feeding and the structure of its diet on Kolguev Island during the nesting and postnesting periods (May 27–July 29) have been examined. The diet structures of the invasive Barnacle Goose and the aboriginal species White-fronted goose (Anser albifrons) and Bean goose (A. fabalis) have been compared. The probability of interspecific competition and the ecological advantages in the diet patterns of these species have been estimated. If the Barnacle Goose population on Kolguev Island continues to increase, this may led to a decline in the population of aboriginal species of geese on the island.     

Serological and virological survey and resighting of marked wild geese in Germany

In order to investigate the potential role of arctic geese in the epidemiology, the spatial and temporal spread of selected avian diseases, in autumn 2002, a virological and serological survey designed as capture-mark-resighting study was conducted in one of the most important coastal resting sites for migratory waterfowl in Germany. Oropharyngeal, cloacal swabs and blood samples were collected from a total of 147 birds comprising of three different arctic geese species including White-fronted Goose (Anser albifrons), Tundra Bean Goose (Anser fabalis rossicus), Pink-footed Goose (Anser brachyrhynchus) as well as from 29 non-migratory Canada Geese (Branta canadensis). Altogether, six adeno-like viruses (ALV; 95% CI, 1.74?C9.92%) and two avian paramyxoviruses (APMV-4; 95% CI, 0.19?C5.53%) were isolated mainly from juvenile White-fronted Geese. In addition, four Canada Geese were infected with lentogenic APMV-1 (95% CI, 3.89?C31.66%) at the date of sampling. No avian influenza viruses, reo-like viruses could be isolated despite serological evidence. Likewise, no evidence of current or previous infection by West Nile virus was found. Of the 147 birds tagged in the following years, 137 birds were re-sighted between 2002 and 2008 accumulating to 1925 sightings. About 90% of all sightings were reported from the main wintering and resting sites in Germany and The Netherlands. Eight of the resighted geese were virus positive (ALV and APMV-4) at the time point of sampling in 2002.     

Factors Influencing Reporting and Harvest Probabilities in North American Geese

ABSTRACT We assessed variation in reporting probabilities of standard bands among species, populations, harvest locations, and size classes of North American geese to enable estimation of unbiased harvest probabilities. We included reward (US$10, $20, $30, $50, or $100) and control ($0) banded geese from 16 recognized goose populations of 4 species: Canada (Branta canadensis), cackling (B. hutchinsii), Ross's (Chen rossii), and snow geese (C. caerulescens). We incorporated spatially explicit direct recoveries and live recaptures into a multinomial model to estimate reporting, harvest, and band-retention probabilities. We compared various models for estimating harvest probabilities at country (United States vs. Canada), flyway (5 administrative regions), and harvest area (i.e., flyways divided into northern and southern sections) scales. Mean reporting probability of standard bands was 0.73 (95% CI = 0.69–0.77). Point estimates of reporting probabilities for goose populations or spatial units varied from 0.52 to 0.93, but confidence intervals for individual estimates overlapped and model selection indicated that models with species, population, or spatial effects were less parsimonious than those without these effects. Our estimates were similar to recently reported estimates for mallards (Anas platyrhynchos). We provide current harvest probability estimates for these populations using our direct measures of reporting probability, improving the accuracy of previous estimates obtained from recovery probabilities alone. Goose managers and researchers throughout North America can use our reporting probabilities to correct recovery probabilities estimated from standard banding operations for deriving spatially explicit harvest probabilities.     

Circumpolar variation in morphological characteristics of Greater White-fronted Geese Anser albifrons

Capsule Greater White-fronted Geese show significant variation in body size from sampling locations throughout their circumpolar breeding range.

Aims To determine the degree of geographical variation in body size of Greater White-fronted Geese and identify factors contributing to any apparent patterns in variation.

Methods Structural measures of >3000 geese from 16 breeding areas throughout the Holarctic breeding range of the species were compared statistically.

Results Palearctic forms varied clinally, and increased in size from the smallest forms on the Kanin and Taimyr peninsulas in western Eurasia to the largest forms breeding in the Anadyr Lowlands of eastern Chukotka. Clinal variation was less apparent in the Nearctic, as both the smallest form in the Nearctic and the largest form overall (the Tule Goose) were from different breeding areas in Alaska. The Tule Goose was 25% larger than the smallest form. Birds from Greenland (A. a. flavirostris) were the second largest, although only slightly larger than geese from several North American populations. Body size was not correlated with breeding latitude but was positively correlated with temperature on the breeding grounds, breeding habitat, and migration distance. Body mass of Greater White-fronted Geese from all populations remained relatively constant during the period of wing moult. Morphological distinctness of eastern and western Palearctic forms concurs with earlier findings of complete range disjunction.

Conclusions Patterns of morphological variation in Greater White-fronted Geese across the Holarctic can be generally attributed to adaptation to variable breeding environments, migration requirements, and phylo-geographical histories.     

Changes in abundance of water birds species in southern Bohemia (Czech Republic) in the last 10 years

In 1981–1992, the breeding fauna of 153 fishponds was studies in three fishpond regions in south Bohemia (Czechoslovakia). On each pond, all water and wetland birds were censused by the Two-check method, which consists of adult birds counts during each breeding season (the first in the second part of May, and the second in the second part of June). We assessed the numbers of all species living in water and wetland habitats in the breeding season.The decline in abundances (expressed as number of individuals) of ducks (Anatinae), grebes (Podicipediformes), Coot (Fulica atra), Moorhen (Galinulla chloropus), Black-headed Gull (Larus ridibundus) were the most marked changes recorded. Marked increase in abundances was found in Cormorant (Phalacrocorax carbo) and Mute Swan (Cygnus olor) during the whole decade, whereas in Graylag Goose (Anser anser) the increase was restricted to the first half of the period under study. Numbers of charadriform and passeriform birds fluctuated in the dependence of water level variation.     

Flyway population delineation in Taiga Bean Geese Anser fabalis fabalis revealed by multi‐element feather stable isotope analysis

Fundamental to effective management of migratory waterbird populations is an understanding of their flyway delineation. Taiga Bean Geese Anser fabalis fabalis wintering in NW Denmark, Scotland and England are considered to originate from northern and central Sweden, southern and central Norway (‘Western flyway’), those wintering in southern Sweden, NE and southern Denmark are considered to originate from northern Fennoscandia and western Russia (‘Central flyway’), and those wintering in eastern Germany and Poland (which show far less favourable conservation status) are thought to come from western Siberia (‘Eastern 1 flyway’), although evidence to demonstrate this has largely been lacking. Evidence for different natal and moult origins of Taiga Bean Geese was investigated using stable isotope analyses of feathers of four elements (δ²H, δ¹³C, δ¹⁵N and δ³⁴S). There were significant differences in isotopic composition of feathers from Swedish (Central) and German (Eastern 1) wintering populations and those moulting in Sweden in late summer (Western), which validated the three proposed major management flyway units above. The strong continental gradient in the stable hydrogen isotope ratios in precipitation (δ²H_p) across the region was used to assign wintering birds geospatially to natal and moulting origin, indicating separate natal and moulting areas for German (n = 37, from western Siberia) and Swedish (n = 20, Fennoscandia and more western Russia) wintering birds. These results confirm the largely discrete nature of these three flyways and contribute significantly to our ability to deliver effective targeted and appropriate research, monitoring and management actions throughout the ranges of these flyways.     

Changes in the wildfowl populations wintering on the Severn Estuary

Monthly winter counts of seven major wildfowl species show that, since 1960, Bewick's swan, shelduck, wigeon, teal and pintail have significantly increased in both the Severn and Britain as a whole; European White-fronted geese have shown no trend on the Severn but have significantly declined in Britain; mallard show no trend on the Severn but have increased in Britain. All except shelduck show a correlation between the trends in Britain and the Severn Estuary, while all but mallard and pintail rank as internationally important on the Severn. In recent years the Severn has assumed a considerable importance for pochard and tufted ducks. The status of many species in the Severn Estuary is dependent on the management of key areas.     

Changes in trophic state and aquatic communities in high Arctic ponds in response to increasing goose populations

相似文献   

Is population structure in the European white stork determined by flyway permeability rather than translocation history?

European white stork are long considered to diverge to eastern and western migration pools as a result of independent overwintering flyways. In relatively recent times, the western and northern distribution has been subject to dramatic population declines and country‐specific extirpations. A number of independent reintroduction programs were started in the mid 1950s to bring storks back to historical ranges. Founder individuals were sourced opportunistically from the Eastern and Western European distributions and Algeria, leading to significant artificial mixing between eastern and western flyways. Here we use mitochondrial and microsatellite DNA to test the contention that prior to translocation, eastern and western flyways were genetically distinct. The data show a surprising lack of structure at any spatial or temporal scale suggesting that even though birds were moved between flyways, there is evidence of natural mixing prior to the onset of translocation activities. Overall a high retention of genetic diversity, high N_ef, and an apparent absence of recent genetic bottleneck associated with early 20th century declines suggest that the species is well equipped to respond to future environmental pressures.     

Geese and Red-knobbed Coot on the Kafue Flats in Zambia, 1970–1974

The occurrence, chronology of breeding and wing-moult, and feeding habits of the Pigmy Goose Nettapus auritus, Knob-billed Goose Sarkidiornis melanotos, Spur-winged Goose Plectropterus gambensis, Egyptian Goose Alopochen aegyptiaca and Red-knobbed Coot Fulica cristata on the Kafue Flats in Zambia are described based on observations made between October 1970 and January 1974 at Lochinvar National Park and, from the air, over the central section of the Flats. The Pigmy Goose, Knob-billed Goose, Egyptian Goose and Red-knobbed Coot fed largely by grazing. They were most abundant between March and June, occurring in greatest numbers at Lochinvar. Egyptian Geese occasionally nested on the flood-plain at Lochinvar between August and January, but there was no proof of the other species nesting there. Many Pigmy Geese and male Knob-billed Geese moulted on the lagoon at Lochinvar between March and June; small numbers of Egyptian Geese and Red-knobbed Coot also moulted in the Park, the former between February and May, the latter in June and July. The Spur-winged Goose fed mostly by grazing and grubbing. Numbers on the Flats were greatest between June and November when 60,000–90,000 moved downriver as the floods subsided. Many bred between January and March in the fringing zone and moulted on the floodplain between May and July. A hydroelectric scheme, completed in 1975, may benefit the Pigmy Goose and Red-knobbed Coot but harm the Spur-winged Goose.     

Spatial, temporal, and species variation in prevalence of influenza A viruses in wild migratory birds

Although extensive data exist on avian influenza in wild birds in North America, limited information is available from elsewhere, including Europe. Here, molecular diagnostic tools were employed for high-throughput surveillance of migratory birds, as an alternative to classical labor-intensive methods of virus isolation in eggs. This study included 36,809 samples from 323 bird species belonging to 18 orders, of which only 25 species of three orders were positive for influenza A virus. Information on species, locations, and timing is provided for all samples tested. Seven previously unknown host species for avian influenza virus were identified: barnacle goose, bean goose, brent goose, pink-footed goose, bewick's swan, common gull, and guillemot. Dabbling ducks were more frequently infected than other ducks and Anseriformes; this distinction was probably related to bird behavior rather than population sizes. Waders did not appear to play a role in the epidemiology of avian influenza in Europe, in contrast to the Americas. The high virus prevalence in ducks in Europe in spring as compared with North America could explain the differences in virus-host ecology between these continents. Most influenza A virus subtypes were detected in ducks, but H13 and H16 subtypes were detected primarily in gulls. Viruses of subtype H6 were more promiscuous in host range than other subtypes. Temporal and spatial variation in influenza virus prevalence in wild birds was observed, with influenza A virus prevalence varying by sampling location; this is probably related to migration patterns from northeast to southwest and a higher prevalence farther north along the flyways. We discuss the ecology and epidemiology of avian influenza A virus in wild birds in relation to host ecology and compare our results with published studies. These data are useful for designing new surveillance programs and are particularly relevant due to increased interest in avian influenza in wild birds.     

The creation and management of wildfowl refuges as a means of lessening the conflict between farmers and geese

With increases in goose numbers and incidences of problems with other than traditionally damaging species on new crops conflict has greatly increased recently. This paper suggested that the creation of managed goose refuges in problem areas provided the best long-term solution. Examples of the success of refuges were given based on experience at two Wildfowl Trust goose refuges. Goose use of land surrounding these refuges had decreased following their creation and the goose carrying capacity of refuge land had been increased by up to 150% by controlling winter disturbance, cropping and stock grazing. This had been achieved without drastically changing the agricultural regime, which in both areas was in line with local practices. Because of great annual fluctuations in goose numbers following variations in breeding success and of the difficulty of predicting goose carrying capacity, assessments of the area of land required to accommodate geese in conflict with agriculture in Britain can only be very approximate. Based on goose counts in 1975-6, some 150000 geese (of four species) were potentially involved and the land area required as refuges to accommodate all of them (giving a maximum figure) in the region of 20 000 acres (7800 ha).     

Genetic diversity of two mitochondrial DNA genes in Spirometra erinaceieuropaei (Cestoda: Diphyllobothridae) from Poland

The tapeworm species Spirometra erinaceieuropaei was documented mainly in Asia and Europe. In recent years, plerocercoid larvae (spargana) of this parasite have been found in different hosts in north‐eastern Poland. The evolutionary history and way of S. erinaceieuropaei spreading across Eurasia have been not described yet. However, this phenomenon could be closely related to the evolutionary history and migration routes of studied tapeworm host species. We investigated the genetic variability and divergence pattern among S. erinaceieuropaei populations in intermediate and paratenic hosts from north‐eastern Poland based on complete mitochondrial sequences of cytochrome b (cytb) and cytochrome c oxidase subunit I (cox1) genes. Analysis of 319 consolidated sequences of these two genes showed no genetic structure across study area. Comparison of sequences from Poland and China showed distinct separation of S. erinaceieuropaei populations from these two regions. They split from their common ancestor approximately 28.6 million years ago. Demographic expansion of Polish population of S. erinaceieuropaei started from glacial refugia approximately 12.5 thousand years ago, and recent population expansion has been observed in the tapeworm population from north‐eastern Poland.     

Fads1 and 2 are promoted to meet instant need for long-chain polyunsaturated fatty acids in goose fatty liver

Global prevalence of non-alcoholic fatty liver disease (NAFLD) constitutes a threat to human health. Goose is a unique model of NAFLD for discovering therapeutic targets as its liver can develop severe steatosis without overt injury. Fatty acid desaturase (Fads) is a potential therapeutic target as Fads expression and mutations are associated with liver fat. Here, we hypothesized that Fads was promoted to provide a protection for goose fatty liver. To test this, goose Fads1 and Fads2 were sequenced. Fads1/2/6 expression was determined in goose liver and primary hepatocytes by quantitative PCR. Liver fatty acid composition was also analyzed by gas chromatography. Data indicated that hepatic Fads1/2/6 expression was gradually increased with the time of overfeeding. In contrast, trans-C18:1n9 fatty acid (Fads inhibitor) was reduced. However, enhanced Fads capacity for long-chain polyunsaturated fatty acid (LC-PUFA) synthesis was not sufficient to compensate for the depleted LC-PUFAs in goose fatty liver. Moreover, cell studies showed that Fads1/2/6 expression was regulated by fatty liver-associated factors. Together, these findings suggest Fads1/2 as protective components are promoted to meet instant need for LC-PUFAs in goose fatty liver, and we propose this is required for severe hepatic steatosis without liver injury.

     

Abundances of waterbird species on lakes in Argentine Patagonia as a function of season,lake size and the presence of mink

Regular counts from 2005 to 2009 were made of the waterbirds inhabiting lakes and ponds in Lanín National Park in the southwestern part of Neuquén Province, Argentina, a landscape dominated by Andean–Patagonian wetlands and forests. Bird surveys conducted on 21 wetland areas detected 8,311 individuals belonging to 27 species from 9 families. The most abundant and frequent species were Ashy-headed Goose (Chloephaga poliocephala), Speckled Teal (Anas flavirostris), Red-gartered Coot (Fulica armillata) and White-winged Coot (Fulica leucoptera). The presence and abundance of bird species with respect to wetland surface area was examined. Small lakes (<100 ha) had higher numbers of individuals, but some species such as the Neotropic Cormorant (Phalacrocorax olivaceus), Great Grebe (Podiceps major), Flying Steamer Duck (Tachyeres patachonicus) and Spectacled Duck (Anas specularis) were more abundant at larger lakes. Speckled Teal, Red Shoveler (Anas platalea) and Chiloe Wigeon (A. sibilatrix) were more common in small- and medium-sized lakes. Most waterbird species were found at a smaller percentage of the lakes where mink were present than at mink-free lakes. Although the ponds and lakes studied are protected within the network of this Argentine National Park, such protection is not implemented effectively. Hence, their future conservation faces several potential threats such as American mink expansion, tourism, fishing and hunting. This information could contribute to the development of management guidelines for the effective conservation of Patagonian wetlands.