Tundra Bean Goose Research Articles

Environmental DNA reveals a presence of Anser fabalis (Bean Goose) and an absence of A. erythropus (Lesser White-fronted Goose) in Finnish Northern Lapland

Abstract Detecting rare and elusive species from vast wilderness areas poses significant challenges. The Fennoscandian population of Anser erythropus (Lesser White-fronted Goose) is among the most endangered bird populations in Europe, with only 25–30 breeding pairs remaining in Northern Norway. Historically, its former breeding range extended across the mountainous regions of Fennoscandia. Thanks to targeted conservation efforts during the 21st century, A. erythropus has started to recolonize some of its former breeding areas in Norway and possibly also in Finland. Anser serrirostris rossicus (Tundra Bean Goose) is classified as Endangered (EN) in Finland, with just a few breeding pairs in northernmost Finnish Lapland with a poorly known breeding range. It breeds in higher numbers in Finnmark Norway and is listed as Vulnerable (VU) in Norway. Anser fabalis fabalis (Taiga Bean Goose), classified as Endangered in Norway, can also breed in the same area in low numbers. To locate individuals of these elusive goose species during breeding seasons, we used environmental DNA (eDNA) extracted from filtered lake water from selected lakes in northern Finland. We amplified and sequenced a short region of the mitochondrial control region to identify the species. Additionally, for positive controls, we sampled eDNA from the water of a Finnish spring staging site and known Norwegian breeding sites of the A. erythropus, from which eDNA of the A. erythropus was identified. eDNA of the A. erythropus was not detected within the former Finnish breeding range. Based on this, the A. erythropus has either not recolonized its former breeding habitats in Finland, the correct lakes were not sampled, the eDNA concentration was below detection limits, or due to other methodological issues. Anser serrirostris rossicus was detected in 3 lakes and A. fabalis fabalis in 10 lakes, providing new information about the breeding distribution of Bean Geese in Finnish Lapland.

Population trend and spatio-temporal distribution of Greater White-fronted (Anser albifrons) and Bean Geese (Anser fabalis) in Korea

Geese have undergone significant changes in their distribution and population size due to human-induced impacts. To improve our understanding of the two main geese populations in East Asia — Greater White-fronted (Anser albifrons; GWFG) and Bean Geese (Anser fabalis sensu lato; BEAG), which includes the Tundra A. f. serrirostris (TDBG) and Taiga Bean Geese A. f. middendroffi (TGBG) — this study estimated their long- and short-term trends and the migration strategies based on their distribution during the migratory and wintering seasons, using nationwide census data collected over 24 years in Korea. The TRIM (TRends and Indices for Monitoring data) analysis supported a robust long-term population increase since 1999, recently stabilizing around 150,000 individuals in GWFG and 100,000 in TDBG, respectively. But TGBG stabilized at around 7000 with no significant change of population over time. The shorter-term trends within a season suggested that wintering populations of GWFG and TDBG in China might stop over in Korea in their autumn migration before their sea-crossing, evidenced by the large congregation near the Yellow Sea coast followed by gradual decrease. In contrast to autumn, there was no similar peak in spring migration, suggesting the potential for elliptical migration of some populations around the Yellow Sea. Our findings indicate a growing East Asian population and implies one of the migration strategies of the Greater White-fronted and Tundra Bean Geese. By collaborating with recent tracking data, long-term monitoring efforts could offer more detailed insights into population trends and migration strategies, thereby contributing to the effective management and conservation of goose species in East Asia.

Comparative analysis of intestinal flora community composition and diversity of Anas platyrhynchos and Anser fabalis in the Yellow River Delta

Abstract The Yellow River Delta wetland is a habitat for wintering waterfowl, where mallard (Anas platyrhynchos) and tundra bean goose (Anser fabalis) are commonly observed. Although the intestinal flora plays a pivotal role in maintaining host health and promoting nutrient absorption, it remains unclear whether the same overwintering habitat and challenging feeding conditions specifically affect the composition and diversity of intestinal flora in both species. Here, high-throughput sequencing was used to compare the intestinal bacterial communities of mallard and tundra bean goose from the same region. There was no significant difference in alpha diversity and beta diversity between the two species. Firmicutes and Proteobacteria were the two predominant phyla, accounting for more than 50.00% of the total. They enhanced the nutrient absorption and metabolic efficiency during overwintering. Catellicoccus was the most dominant genus in the intestinal flora of tundra bean goose, accounting for 33.91%, whereas Clostridium sensu stricto 1 was the most dominant genus in mallard, accounting for 7.34%. This difference is considered to be related to the feeding habits of these two species. No significant differences in the structure and diversity of intestinal bacterial communities were observed between mallard and tundra bean goose, and the similarity of intestinal flora between them was high. This study deepens our understanding of the intestinal flora of two coexisting species with different dietary preferences in the Yellow River Delta. It also lays the foundation for waterfowl disease prevention in this area, carrying significant scientific and practical implications for biodiversity and ecosystem conservation.

A vadlúd monitoring eredményei a 2020/2021-es idényben Magyarországon

Results of Geese Monitoring in Hungary in the season 2020/2021. The author presents the results of the HUNGARIAN GEESE MONITORING (Table 1.) for 2020/2021 in the form of a data base. After reviewing the basic data recorded at each site of observation (Table 3-21.) he analyse the obtained data separately for each species, i.e. Brent Goose (Branta bernicla) (Table 22., Map 1., Figure 1-2.), Barnacle Goose (Branta leucopsis) (Table 23., Map 2., Figure 3-4.), Red-breasted Goose (Branta ruficollis) (Table 24, Map 3., Figure 5-6.), Bar-headed Goose (Anser indicus) (Table 25, Map 4, Figure 7.), Greylag Goose (Anser anser) (Table 26., Map 5., Figure 8-10.), Tundra Bean Goose (Anser serrirostris rossicus) (Table 27., Map 6., Figure 11-13.), Taiga Bean Goose (Anser fabalis) (Table 28, Map 7, Figure 14.), Pink-footed Goose (Anser brachyrhynchus) (Table 29., Map 8., Figure 15.), White-fronted Goose (Anser albifrons) (Table 30., Map 9., Figure 16-18.), Lesser White-fronted Goose (Anser erythropus) (Table 31., Map 10., Figure 19-20.), as well as for the total of observed geese (Table 32., Figure 21-24.). In respect of dominance – when data recorded monthly in each of the observed sites (Table 3-21., Figure 25.) or those referring to the total of geese present in Hungary (Table 33., Figure 25.) are analysed, it is found that in conformity with the numbers of individuals, also in the season 2020/2021 White-fronted Goose was the most common goose species in Hungary (max. 265 010 birds, max. 96%), followed by Greylag Goose (max. 39 261 birds, max. 100%), Tundra Bean Goose (max. 711 birds, max. 0-1%) ranking third. Dominance of Red-breasted Goose and Lesser White-fronted Goose – both are globally threatened species – ranged both from 0% to <1% (max. 147 and 10 birds). If the data obtained for the season 2020/2021 are fitted into the data series of long-term monitoring, the following conclusions can be drawn from the actual changes in population numbers of the geese species in the Pannon region. In the season 2020/2021, we observed max. 2 Brent Geese, max. 1 Barnacle Goose, max. 1 Bar-headed Goose, max. 1 Pink-footed Goose and max. 6 Taiga Bean Goose. For the globally threatened Red-breasted Goose may be considered higher (+40% – 147 birds) to the maximum counted in the season 2019/2020 (105 birds), but much lower to the record number counted in the season 2014/2015 (1258 birds). Greylag Goose continued to be present with high numbers in Hungary. However, in the new season its peaks (39 261 birds) were found to be higher (+4%) those counted in the previous 2019/2020 season (37 707 birds). Peak number of Tundra Bean Goose (711 birds) was lower (–8%) as the maximum counted in the season 2019/2020 (769 birds). The dramatic decline in the dynamics of the Tundra Bean Goose population continued and stabilized in the Pannon Region. Peak number of White-fronted Goose (265 010 birds) was 5% higher as the maximum counted in 2019/2020 (250 888 birds). For the globally threatened Lesser White-fronted Goose may be considered higher (10 birds) to the maximum counted in the season 2019/2020 (9 birds). The maximum numbers of total geese in the season 2020/2021 registered simultaneously (306 526 birds) was 11% higher to the maximum number of the season 2019/2020 (275 164 birds).

Avian species survey with citizen-science data in Janghang Wetland, Goyang, Republic of Korea.

Monitoring of avian populations in Janghang Wetland, Goyang, Republic of Korea (ROK) is based on citizen science (also called community-based monitoring). This monitoring data can be used to track avian density, population status and waterbird census at local, national and regional levels. The Ministry of Environment (MoE) ROK has surveyed since 1999, including Odusan Unification Tower to Ilsan Bride, which connects the cities of Gimpo and Goyang along the Han River estuary. However, it has not covered Janghang Wetland, which is located in the Han River estuary at the transboundary between the two Koreas. The Janghang Wetland is a protected wetland in the Demilitarized Zone (DMZ) between the two Koreas. In 2019, Janghang Wetland was designated as a Flyway Network Site by Goyang City and the East Asian-Australasian Flyway Partnership. This Network site is a voluntary collaboration and includes many internationally significant wetlands for waterbirds that still lack formal national protection. In addition, it was designated as a Ramsar site in 2021. The wetland currently supports wintering population of White-naped Crane (Grusvipio), species listed as vulnerable and Tundra Bean Goose (Ansercygnoides), spring-autumn migration population of Swan Goose (Ansercygnoid), species listed as vulnerable and a breeding population of Black-faced Spoonbill (Plataleaminor), species listed as endangered in summer. We provide data that the Janghang Wetland is a significant area for migration and breeding for waterbirds; and that Han River estuary is also internationally important for waterbirds during the migratory bird season. We observed 14 orders, 42 families and 132 species. The surveys also observed the critically-endangered Black-faced Spoonbill (Plataleaminor), Swan Goose (Ansercygnoides), White-naped Crane (Grusvipio), Whooper Swan (Cygnuscygnus) and Peregrine Falcon (Falcoperegrinus). We also observed the Black-faced Spoonbill, Great Egret, Little Egret, Great Cormorant, Eastern Spot-billed Duck, Pheasant and Brown-eared Bulbul at the sensor camera point and White-naped Crane, Hooded Crane, Bean Goose, White-fronted Goose, Snow Goose, Swan Goose, Great Cormorant and Eastern Spot-billed Duck at the closed-circuit television camera point from the camera-trap surveys. Based on the species recorded, the survey area is of clear importance for biodiversity conservation.

Sensitivity analysis of collision risk at wind turbines based on flight altitude of migratory waterbirds

Abstract A rapid increase in wind power generation has led to bird collisions becoming a serious problem worldwide. Developing useful sensitivity maps to select low‐risk sites for birds is an urgent issue. For migratory birds, such as geese and swans, that visit different habitats throughout their life cycle, it is important to conduct risk assessments that take into account their behavioural characteristics in each habitat. Geese and swans fly and migrate at varying altitudes (above the ground) ranging from 10 to hundreds of metres. Accurate predictions of avian flight altitudes are essential in assessing the risks of collisions with human‐made structures. We first obtained location data for four species of geese and swans to identify their spring migratory routes within Japan (Bean Goose Anser fabalis and Anser serrirostris, Greater White‐fronted Goose Anser albifrons, Tundra Swan Cygnus columbianus bewickii and Whooper Swan Cygnus cygnus). As all four species used the same roosts and overlapping foraging areas from winter to spring, a single migratory route was defined by integrating the location data of the four species. Flight trajectories were tracked using an ornithodolite. The median flight height for these four species in all landscape types was 150 m or less. Then a LASSO regression model was created with flight altitude obtained as the response variable and topographic and landscape factors as explanatory variables. Trends in flight altitude with environmental differences were similar for the four species, indicating that topographical factors strongly influence flight altitude. Finally, a statistical model was used to predict flight altitudes along migration routes. The sensitivity maps we generated showed that for all four species, most flight heights during spring were within the wind turbine range, suggesting that their risk of collision with wind turbines was greater along their migratory route. Sensitivity maps that accurately reflect avian flight characteristics help provide useful information when considering the location of further wind turbine construction.

Highly differentiated loci resolve phylogenetic relationships in the Bean Goose complex

BackgroundReconstructing phylogenetic relationships with genomic data remains a challenging endeavor. Numerous phylogenomic studies have reported incongruent gene trees when analyzing different genomic regions, complicating the search for a ‘true’ species tree. Some authors have argued that genomic regions of increased divergence (i.e. differentiation islands) reflect the species tree, although other studies have shown that these regions might produce misleading topologies due to species-specific selective sweeps or ancient introgression events. In this study, we tested the extent to which highly differentiated loci can resolve phylogenetic relationships in the Bean Goose complex, a group of goose taxa that includes the Taiga Bean Goose (Anser fabalis), the Tundra Bean Goose (Anser serrirostris) and the Pink-footed Goose (Anser brachyrhynchus).ResultsFirst, we show that a random selection of genomic loci—which mainly samples the undifferentiated regions of the genome—results in an unresolved species complex with a monophyletic A. brachyrhynchus embedded within a paraphyletic cluster of A. fabalis and A. serrirostris. Next, phylogenetic analyses of differentiation islands converged upon a topology of three monophyletic clades in which A. brachyrhynchus is sister to A. fabalis, and A. serrirostris is sister to the clade uniting these two species. Close inspection of the locus trees within the differentiated regions revealed that this topology was consistently supported over other phylogenetic arrangements. As it seems unlikely that selection or introgression events have impacted all differentiation islands in the same way, we are convinced that this topology reflects the ‘true’ species tree. Additional analyses, based on D-statistics, revealed extensive introgression between A. fabalis and A. serrirostris, which partly explains the failure to resolve the species complex with a random selection of genomic loci. Recent introgression between these taxa has probably erased the phylogenetic branching pattern across a large section of the genome, whereas differentiation islands were unaffected by the homogenizing gene flow and maintained the phylogenetic patterns that reflect the species tree.ConclusionsThe evolution of the Bean Goose complex can be depicted as a simple bifurcating tree, but this would ignore the impact of introgressive hybridization. Hence, we advocate that the evolutionary relationships between these taxa are best represented as a phylogenetic network.

Predicting spatio‐temporal distributions of migratory populations using Gaussian process modelling

Abstract Knowledge concerning spatio‐temporal distributions of populations is a prerequisite for successful conservation and management of migratory animals. Achieving cost‐effective monitoring of large‐scale movements is often difficult due to lack of effective and inexpensive methods. Taiga bean goose Anser fabalis fabalis and tundra bean goose A. f. rossicus offer an excellent example of a challenging management situation with harvested migratory populations. The subspecies have different conservation statuses and population trends. However, their distribution overlaps during migration to an unknown extent, which, together with their similar appearance, has created a conservation–management dilemma. Gaussian process (GP) models are widely adopted in the field of statistics and machine learning, but have seldom been applied in ecology so far. We introduce the R package gplite for GP modelling and use it in our case study together with birdwatcher observation data to study spatio‐temporal differences between bean goose subspecies during migration in Finland in 2011–2019. We demonstrate that GP modelling offers a flexible and effective tool for analysing heterogeneous data collected by citizens. The analysis reveals spatial and temporal distribution differences between the two bean goose subspecies in Finland. Taiga bean goose migrates through the entire country, whereas tundra bean goose occurs only in a small area in south‐eastern Finland and migrates later than taiga bean goose. Synthesis and applications. Within the studied bean goose populations, harvest can be targeted at abundant tundra bean goose by restricting hunting to south‐eastern Finland and to the end of the migration period. In general, our approach combining citizen science data with GP modelling can be applied to study spatio‐temporal distributions of various populations and thus help in solving challenging management situations. The introduced R package gplite can be applied not only to ecological modelling, but to a wide range of analyses in other fields of science.

Does the Tundra Bean Goose (Anser serrirostris) Follow the Green Wave Throughout its Entire Spring Migration?

Does the Tundra Bean Goose (Anser serrirostris) Follow the Green Wave Throughout its Entire Spring Migration?

Modeling Eastern Russian High Arctic Geese (Anser fabalis, A. albifrons) during moult and brood rearing in the \u2018New Digital Arctic\u2019

Many polar species and habitats are now affected by man-made global climate change and underlying infrastructure. These anthropogenic forces have resulted in clear implications and many significant changes in the arctic, leading to the emergence of new climate, habitats and other issues including digital online infrastructure representing a ‘New Artic’. Arctic grazers, like Eastern Russian migratory populations of Tundra Bean Goose Anser fabalis and Greater White-fronted Goose A. albifrons, are representative examples and they are affected along the entire flyway in East Asia, namely China, Japan and Korea. Here we present the best publicly-available long-term (24 years) digitized geographic information system (GIS) data for the breeding study area (East Yakutia and Chukotka) and its habitats with ISO-compliant metadata. Further, we used seven publicly available compiled Open Access GIS predictor layers to predict the distribution for these two species within the tundra habitats. Using BIG DATA we are able to improve on the ecological niche prediction inference for both species by focusing for the first time specifically on biological relevant population cohorts: post-breeding moulting non-breeders, as well as post-breeding parent birds with broods. To assure inference with certainty, we assessed it with 4 lines of evidence including alternative best-available open access field data from GBIF.org as well as occurrence data compiled from the literature. Despite incomplete data, we found a good model accuracy in support of our evidence for a robust inference of the species distributions. Our predictions indicate a strong publicly best-available relative index of occurrence (RIO). These results are based on the quantified ecological niche showing more realistic gradual occurrence patterns but which are not fully in agreement with the current strictly applied parsimonious flyway and species delineations. While our predictions are to be improved further, e.g. when synergetic data are made freely available, here we offer within data caveats the first open access model platform for fine-tuning and future predictions for this otherwise poorly represented region in times of a rapid changing industrialized ‘New Arctic’ with global repercussions.

Annual survival estimates of Taiga Anser fabalis and Tundra Bean Geese A. serrirostris wintering in The Netherlands, 1967–1987

An estimated 50% decline in Taiga Bean Geese A. fabalis between the mid-1990s and 2015 contrasted increasing numbers of Tundra Bean Goose A. serrirostris wintering in Western Europe at the same time. Seber dead-recovery analysis of metal-ringed individuals used to investigate year- and age effects on survival estimates from historical ringing data of both taxa caught in The Netherlands 1964–1987 generated annual survival rates of 0.716 (0.013 SE) and 0.803 (0.007) for A. fabalis and 0.824 (0.006) and 0.831 (0.005) for A. serrirostris for first-winter and adults, respectively.

Life in the extreme environment: Structure and species richness of bird assemblages on Yuzhny Island of Novaya Zemlya, Russia

Birds play a vital role in arctic environments, being multi-functional ecosystem engineers, but these animals are heavily impacted by recent climate warming. Bird assemblages on the Arctic Ocean archipelagoes are poorly known, because many such areas are hardly accessible to scientists. Novaya Zemlya, one of the most enigmatic places in the World, was a closed military area from the late 1940s. This gigantic mountainous archipelago can be considered a terra incognita by means of modern faunal, taxonomic, and ecological research. In the present study, we provide the first qualitative data on bird assemblages of the Yuzhny Island of Novaya Zemlya, estimate the diversity of bird species through a range of habitats, and underscore environmental factors determining the spatial distribution of avifauna in the arctic tundra biome. In terrestrial habitats, Tundra Bean Goose (Anser fabalis rossicus), Barnacle Goose (Branta leucopsis) and Snow Bunting (Plectrophenax nivalis) were the most abundant species. In freshwater and coastal marine habitats, both these Arctic-breeding goose taxa, and Black-legged Kittiwake (Rissa tridactyla), Common Eider (Somateria mollissima) and Thick-billed Murre (Uria lomvia) were the dominant species. The most species-rich bird assemblages (11-15 species) were associated with willow tundra, freshwater lakes, and coastal sea habitats, while only a few species were recorded in dry rocky habitats, open sea environments, and littoral areas of lakes and the sea. Mountain rocky heathlands covering most of the area of Yuzhny Island were scarcely populated by birds, with only a few species recorded frequently there, such as the Rough-legged Buzzard (Buteo lagopus) and Snow Bunting. Our findings highlight that the bird assemblages on Novaya Zemlya share low species richness and that these assemblages contain a large proportion of sea and shore bird species even in terrestrial habitats. Among the terrestrial birds, only four cold-tolerant, common species successfully colonize these extreme environments during the short summer season.

Avian Surveys in the Korean Inner Border Area, Gimpo, Republic of Korea.

BackgroundBirds are useful environmental indicators as their presence reflects the health of the food web. Bird occurrence, rarity and abundance are reliable indicators of ecosystem health. Monitoring of avian populations in the Republic of Korea (ROK) is a primary requirement due to plummeting populations and the risks to threatened species. The Ministry of Environment of ROK started conducting winter bird censuses in 1999, including inland areas and coast areas, such as Cheorwon, Yeoncheon, Junam Reservoir and Han River. Cheolwon, Yeoncheon and some extent islands in the West Sea have been survey extensively due to iconic bird species, such as White-naped Crane (Grus vipio) or Red-Crowned Crane (Grus japonensis) wintering there. However, the winter bird census has not covered Yu Islet, Han River Estuary. Yu Islet is located within the Han River Estuary, a protected wetland in the Neutral Zone between the two Koreas and north of Gimpo in the ROK. The Islet currently supports a large, mixed breeding colony of waterbirds, such as one of the nation’s largest concentration of breeding Great Cormorants (Phalacrocorax carbo) and smaller numbers of breeding Black-faced Spoonbill (Platalea minor), Grey Heron (Ardea cinereal), Great Egret (Ardea alba) and Intermediate Egret (Ardea intermedia). Access to the area has long been restricted for military reasons, but recently, regular survey activity is possible supported by Gimpo City and the military base in Gimpo from November 2018.New informationHere, we provide data demonstrating that Yu Islet is important for breeding for waterbirds; and that the northern Gimpo part of Han River Estuary is also internationally important for waterbirds during the migratory bird season, as defined by the Ramsar Convention (Ramsar 1971, RRC-EA 2017). In particular, four waterbird species were found during the survey in the Main Survey Area: Swan Goose (Anser cygnoides), Taiga Bean Goose (Anser fabalis), Tundra Bean Goose (Anser serrirostris) and Greater White-fronted Goose (Anser frontalis). Once considered widespread in East Asia and abundant, the world population of Swan Goose is now estimated at only 60,000 - 78,000 individuals (Wetlands International 2020) and the species is assessed by BirdLife International as globally Vulnerable (BirdLife International 2020). The 1,010 Swan Goose (Anser cygnoides) counted on the vegetated mudflats at Jogang-Ri in the Main Survey Area on 27 November 2018 represents more than 1% of the total world population of this species. Notably, it is also the highest count of this species in the ROK for at least a decade. The count confirms the continuing international importance of the Han River Estuary for the survival of the Swan Goose. The number counted in November had fallen to 250 by 28 December 2018; and none was recorded in the Main Survey Area in January or February 2019. Although searched for in March, none was noted during the northward migration either. The surveys also found small numbers of nationally-scarce Grey-capped Pygmy Woodpecker (Yungipicus canicapillus) in several areas of woodland surrounded by the Han River Estuary. By selecting the most species-rich count within a given month in each of the two survey sectors, the number of species we recorded ranged from a minimum 29 in January to a maximum of 65 in April 2019. Based on the species recorded, the survey area is clearly important for avian conservation. Its importance derives from the combination of the extensive areas of high-quality wetland and its geographic location within one of the Korea Peninsula’s largest and most important remaining wetland ecosystems, the Han River Estuary. Our surveys resulted in the detection of a substantial number of bird species, especially in March and April when forest-breeding birds are more obviously vocal. The survey result is provided in the supplementary material (Suppl. material 1).

Reducing human pressure on farmland could rescue China\u2019s declining wintering geese

BackgroundWhile goose populations worldwide benefit from food provided by farmland, China’s threatened wintering goose populations have failed to capitalize on farmland. It has been proposed that, due to an exceptionally intense human pressure on Chinese farmland, geese cannot exploit farmland in their wintering sites and hence are confined to their deteriorating natural habitat. If this were true, locally decreasing this human pressure on farmland ‘refuges’ would represent a promising conservation measure.MethodsWe investigate habitat use of two declining migratory goose species in their core wintering (Yangtze River Floodplain) and stopover (Northeast China Plain) regions, compare the human pressure level at both regions, and adopt a mixed-effect resource selection function model to test how human pressure, food resource type (farmland or wetland/grass), distance to roosts, and their interaction terms influence the utilization of food resources for each species and region. To this aim we use satellite tracking of 28 tundra bean geese Anser serrirostris and 55 greater white-fronted geese A. albifrons, a newly produced 30 m land cover map, and the terrestrial human footprint map.ResultsGeese use farmland intensively at their stopover site, but hardly at their wintering site, though both regions have farmland available at a similar proportion. The human pressure on both farmland and wetland/grass is significantly lower at the stopover region compared to the wintering region. At both sites, the two goose species actively select for farmland and/or wetland/grass with a relatively low human pressure, positioned relatively close to their roosting sites.ConclusionsOur findings suggest that if human pressure were to decrease in the farmlands close to the roost, China’s wintering geese could benefit from farmland. We recommend setting aside farmland near roosting sites that already experiences a relatively low human pressure as goose refuges, and adopt measures to further reduce human pressure and increase food quality and quantity, to help counter the decline of China’s wintering goose populations. Our study has important conservation implications and offers a practical measure for migratory waterfowl conservation in areas of high human-wildlife conflict.

Recent introgression between Taiga Bean Goose and Tundra Bean Goose results in a largely homogeneous landscape of genetic differentiation

Several studies have uncovered a highly heterogeneous landscape of genetic differentiation across the genomes of closely related species. Specifically, genetic differentiation is often concentrated in particular genomic regions (“islands of differentiation”) that might contain barrier loci contributing to reproductive isolation, whereas the rest of the genome is homogenized by introgression. Alternatively, linked selection can produce differentiation islands in allopatry without introgression. We explored the influence of introgression on the landscape of genetic differentiation in two hybridizing goose taxa: the Taiga Bean Goose (Anser fabalis) and the Tundra Bean Goose (A. serrirostris). We re-sequenced the whole genomes of 18 individuals (9 of each taxon) and, using a combination of population genomic summary statistics and demographic modeling, we reconstructed the evolutionary history of these birds. Next, we quantified the impact of introgression on the build-up and maintenance of genetic differentiation. We found evidence for a scenario of allopatric divergence (about 2.5 million years ago) followed by recent secondary contact (about 60,000 years ago). Subsequent introgression events led to high levels of gene flow, mainly from the Tundra Bean Goose into the Taiga Bean Goose. This scenario resulted in a largely undifferentiated genomic landscape (genome-wide FST = 0.033) with a few notable differentiation peaks that were scattered across chromosomes. The summary statistics indicated that some peaks might contain barrier loci while others arose in allopatry through linked selection. Finally, based on the low genetic differentiation, considerable morphological variation and incomplete reproductive isolation, we argue that the Taiga and the Tundra Bean Goose should be treated as subspecies.

Does snowmelt constrain spring migration progression in sympatric wintering Arctic‐nesting geese? Results from a Far East Asia telemetry study

Telemetry data from sympatric Eastern Tundra Bean Geese Anser serrirostris captured on their winter quarters in the Yangtze River Floodplain, China, tracked to two discrete breeding areas (the Anadyr Region (AR) at 65°N and Central Russian Arctic (CRA) at 75°N) showed that, despite longer migration distance (6300 vs. 5300 km), AR geese reached their destination 23 days earlier than CRA geese as a result of increasingly delayed date of 50% snow cover along the route of CRA geese (based on satellite imagery data). Both groups arrived at breeding areas 8–9 days prior to the local date of 50% snow cover thaw, suggesting optimal timing of arrival for subsequent reproduction. Despite small sample sizes from one season of tracking, these intra‐specific data are the first to suggest that, in time‐limited Arctic‐nesting geese, snowmelt conditions regulated the individual progress and duration of spring migration along the flyway to coincide with arrival at optimal spring conditions on breeding areas.

DNA Sequencing Confirms Tundra Bean Goose (Anser serrirostris serrirostris) Occurrence in the Mississippi Alluvial Valley in Arkansas, USA

First sighting records of rare occurrences may become increasingly important for recognizing changes in distribution, changes in migratory strategies, or increases in hybridization. We documented the first record of a Tundra Bean Goose in the Mississippi Alluvial Valley, the outlet and historic floodplain for much of North America and one of the most important waterfowl wintering areas on the continent. We also document the first genetically confirmed record in the contiguous USA. Bean Goose (Anser fabalis and A. serrirostris) occurrences in North America are rare, especially outside of Alaska. On 24 January 2018, a Tundra Bean Goose (A. s. serrirostris) was harvested by a hunter in a winter-flooded rice field in Desha County, Arkansas, USA, near Dumas. The goose was mixed with a flock of 50 Greater White-Fronted Geese (A. albifrons). Because this individual was legally, albeit accidentally shot, we had the rare and exciting opportunity to obtain morphometric measurements and biological samples. As a result, we were able to verify the species and subspecies through genetic and morphological analysis. We determined the goose was an adult female Tundra Bean Goose, and mitochondrial DNA control region sequence data indicated this specimen was the subspecies A. s. serrirostris.

Spring migration patterns, habitat use, and stopover site protection status for two declining waterfowl species wintering in China as revealed by satellite tracking.

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.

Multi-scale habitat selection by two declining East Asian waterfowl species at their core spring stopover area

Animals respond to their environment at multiple spatial scales that each require different conservation measures. Waterbirds are key bio-indicators for globally threatened wetland ecosystems but their multi-scale habitat selection mechanisms have rarely been studied. Using satellite tracking data and Maximum entropy modeling, we studied habitat selection of two declining waterfowl species, the Greater White-fronted Goose (Anser Albifrons) and the Tundra Bean Goose (A. serrirostris), at three spatial scales: landscape (30, 40, 50 km), foraging (10, 15, 20 km) and roosting (1, 3, 5 km). We hypothesized that the landscape-scale habitat selection was mainly based on relatively coarse landscape metrics, while more detailed landscape features were taken into account for the foraging- and roosting- scale habitat selection. We found that both waterfowl species preferred areas with a larger percentage of wetland and waterbodies at the landscape scale, aggregated waterbodies surrounded by scattered croplands at the foraging scale, and well-connected wetlands and well-connected middle-sized waterbodies at the roosting scale. The main difference in habitat selection for the two species occurred at the landscape and foraging scale; factors at the roosting scale were similar. We suggest that conservation activities should focus on enhancing the aggregation and connectivity of waterbodies and wetlands, and developing less aggregated cropland in the surroundings. Our approach could guide waterbird conservation practices and wetland management by providing effective measures to improve habitat quality in the face of human-induced environmental change.

Changes in local distribution and numbers of staging and wintering Bean Geese Anser fabalis in Scania, south Sweden 1977/1978–2016/2017

Scania in southern Sweden is an important staging and wintering province for the Bean Goose Anser fabalis, especially for the Taiga form A. f. fabalis. Based on counts in October, November and January 1977/1978–2016/2017, and observations of neck-banded individuals, the changes in local distribution are described. When the counts started, large numbers were counted already in October, but autumn numbers steadily decreased as the geese stayed further north in Sweden. The January counts on the other hand increased as the geese wintered in Scania in successively larger numbers rather than leaving Sweden. In January 2017, more than 40,000 or two-thirds of the global population of Taiga Bean Goose were counted in Scania. Within the province, more and more geese concentrated to inland areas and instead of using the Öresund coastal region as in earlier years. Birds from different breeding areas, e.g. from Finland and Sweden, used different parts of Scania. In recent years 3000–9000 of Tundra Bean Geese Anser f. rossicus have been wintering in a small area in northeast Scania.