Goose Species Research Articles

ECOSYSTEM SERVICES ASSOCIATED WITH TROPHIC ANALYSIS OF THE AVIFAUNA OF THE DAM LAKES IN THE MIDDLE AREA OF THE ARGEȘ VALLEY

Ecosystem services are becoming an integral part of science and biodiversity conservation strategies, however, our knowledge is limited to only a few services and in the study area they were not yet evaluated. Birds are ecologically diverse and more beloved and well-known than other vertebrate groups. Some bird species are useful in applications such as environmental quality and are used as early warnings of environmental change and climate change assessment. The economic relevance of birds is not widely quantified and appreciated, and the economic relevance to human society of the ecological roles of birds is neglected. Our research contributes to the improvement of knowledge about birds in the area, to the quantification of some services provided by birds through the trophic analysis of avifauna. This research is useful in understanding their importance to ecosystems and the people who benefit from them, as well as in developing conservation strategies for birds and their habitats. Of the 207 bird species identified in the study area, belonging to 17 orders and 49 families, species with a zoophagous - polyphagous trophic regime and insectivorous species predominate. Thus, representatives of seven food guilds were found, with the predominance of zoophagous - polyphagous and insectivorous species, and the food guilds with the lowest number of species were the piscivorous and vegetarian dietary guilds. The majority (34 - 51 %) of insectivorous species populate the habitats of forests and riparian forests and localities (building area), while among zoophagous – polyphagous (43) and omnivores (19) species dependent on wetlands; most of the insectivorous species are summer visitors (35). Most of the bird species studied also are important from an ecological and economic point of view, providing numerous ecosystem services and play a vital role in agriculture and forestry by managing pest and rodent populations. Thus, insectivorous species (55 species) have a special role in controlling pest insects, in reducing insect populations, and nocturnal birds of prey (with a zoophagous – polyphagous and carnivore - predator trophic regime) have a role in managing rodent populations harmful to agriculture. Some bird species, omnivorous or vegetarian, pollinate or disperse the seeds of plants, and others (Sturnus vulgaris) clean the bodies of other animals (sheep, goats etc.). Corvids and some larids have a certain role on garbage ramps. Birds in the study area also have a cultural role, they are emblematic of nature, they are loved, observed, monitored (birdwatching - recreational activity), fed and used as artistic inspiration and with traditional value in the study area. On the other hand, huge flocks of anseriformes, in the winter aspect, feed on arable land, but they cause damage to farmers, ecosystem disservices, and it is necessary to grant a subsidy per land surface for feeding goose species. By determining the contributions of birds (and biodiversity in general) to humans, their value can be better understood and appreciated at the level of strategies regarding the conservation of biodiversity with special benefits for people.

As the Goose Flies: Migration Routes and Timing Influence Patterns of Genetic Diversity in a Circumpolar Migratory Herbivore

Migration schedules and the timing of other annual events (e.g., pair formation and molt) can affect the distribution of genetic diversity as much as where these events occur. The greater white-fronted goose (Anser albifrons) is a circumpolar goose species, exhibiting temporal and spatial variation of events among populations during the annual cycle. Previous range-wide genetic assessments of the nuclear genome based on eight microsatellite loci suggest a single, largely panmictic population despite up to five subspecies currently recognized based on phenotypic differences. We used double digest restriction-site associated DNA (ddRAD-seq) and mitochondrial DNA (mtDNA) sequence data to re-evaluate estimates of spatial genomic structure and to characterize how past and present processes have shaped the patterns of genetic diversity and connectivity across the Arctic and subarctic. We uncovered previously undetected inter-population differentiation with genetic clusters corresponding to sampling locales associated with current management groups. We further observed subtle genetic clustering within each management unit that can be at least partially explained by the timing and directionality of migration events along with other behaviors during the annual cycle. The Tule Goose (A. a. elgasi) and Greenland subspecies (A. a. flavirostris) showed the highest level of divergence among all sampling locales investigated. The recovery of previously undetected broad and fine-scale spatial structure suggests that the strong cultural transmission of migratory behavior restricts gene flow across portions of the species’ range. Our data further highlight the importance of re-evaluating previous assessments conducted based on a small number of highly variable genetic markers in phenotypically diverse species.

More grazing, more damage? Assessed yield loss on agricultural grassland relates nonlinearly to goose grazing pressure

Abstract In recent decades, conflict between geese and agriculture has increased. Management practices to limit this conflict include concentrating geese in protected areas, derogation shooting or population reduction. To justify such management, we need to understand their effects on goose‐related damages, which requires an understanding of how yield loss is influenced by goose abundance and species interactions. We combined data from monthly goose counts and GPS‐tracked geese to estimate grazing pressures by barnacle, white‐fronted and greylag geese on agricultural grassland in Fryslân, the Netherlands. Using linear mixed models, we related this to damages assessed by professional inspectors. Our results show a positive nonlinear relationship between yield loss and barnacle goose grazing pressure, where assessed damage increases with a decelerating rate as grazing pressure increases. For white‐fronted geese, we find a negative relationship, while for greylag geese both positive and negative relationships occur. For each species, the relationship is influenced by the abundance of the other two. For barnacle geese, the relationship can be explained by selection of fields offering the best balance between food intake and energy expenditure, and by grass regrowth, with highest grazing pressures occurring over a longer time period. The results for the other species are likely due to spatial and temporal differences in foraging preferences compared to barnacle geese, where larger species avoid areas with highest damages. Synthesis and applications. Our results suggest that decreasing herbivore abundance may not translate directly to decreased yield loss, and management tools such as population reduction or derogation shooting should be used with care. Management aimed at concentrating geese in refuges could help to alleviate farmer–goose conflict, although further studies are required to determine if it would lead to damage reduction. We also find that not all species contribute equally to agricultural damage; care should be taken to ensure wildlife management targets the right species.

Proximate Chemical Analysis and Deterioration Criteria of Goose Giblets

Goose meat is one of the most common types of meat consumed worldwide. Egyptian goose species, known as Alopochen aegyptiacus is one of the first reared poultry species. As meat consumption and the need for animal protein rise globally, edible giblets can serve as abundant protein and fat sources. Recently, edible giblets have become readily available, quick-to-prepare food on the market. This study aimed to reveal the proximate chemical composition (protein, fat, moisture, and ash) as well as the deterioration criteria (pH, Total volatile basic nitrogen [TVBN] value, and thiobarbituric acid reactive substance [TBA] value) of Egyptian goose giblets, including liver, gizzard, and heart. A total of 60 samples of goose giblets, including liver, gizzard, and heart (n = 20 each), were collected from Giza and Cairo cities, Egypt. The results showed a marked variation among each giblet type. The goose’s highest protein content (24.48%), moisture content (72.42%), and fat content (12.18%) were recorded for liver, gizzard, and heart, respectively. Moreover, the highest pH (6.72) and TVBN mean value (5.61 mg/100 gm) were indicated in goose’s livers, while the highest TBA mean (0.67 mg malonaldehyde/kg) was obtained from goose’ hearts. These findings may provide a clear understanding for both consumers and possessors about the nutritional value of goose giblets which could be used as an alternative protein source. Moreover, the obtained data in the current study could help meat technology processors to add nutritional value to goose products using goose giblets.

Exploring potential reasons for the increase in the East Asian Greylag GooseAnser anserpopulation by assessing habitat use and use of protected areas

SummaryAmong the six sympatric swan and goose species wintering in the Yangtze River floodplain, only Greylag GooseAnser anserand Bean GooseA. fabalisshowed increasing population trends in the last 20 years. Until now, almost nothing was known about the Greylag Geese breeding on the eastern Mongolian Plateau, which we now know mostly winter in the Yangtze River floodplain. We applied GPS transmitters to 20 Greylag Geese in the Yangtze River floodplain and eastern Mongolia, providing complete tracks of their movements in summer, winter, spring and autumn (n= 6, 8, 8, 7). We overlaid these locations on GIS layers of habitat type and national-level protected areas, and modelled their habitat selection. Geese summered in Dauria Region, Huihe National Nature Reserve, and Wulagai Wetlands (from where 55% of GPS fixes were located in protected areas), wintered in Poyang Lake, Longgan Lake, and Anqing Lakes (43%), and staged around Bohai Bay, Xila Mulun River, and Wulagai Wetlands (spring, 48%; autumn, 45%). Geese mainly used natural ecosystems in summer (essentially grasslands and wetlands/water bodies), but in the other three seasons, used croplands between 17% (spring) and 46% (winter) of the time, with most of the rest of the time spent on wetlands/water bodies. Geese were frequently associated with wetlands and areas close to lakes/wetlands in all seasons, and cropland during winter and spring/autumn migration. These results suggest Greylag Geese in this biogeographical sub-population have increasingly shifted to feeding in croplands during the non-breeding season and enjoy the benefit of using protected areas throughout the year. We infer that these factors could have potentially contributed to elevated survival and reproductive success (relatively high among sampled flocks in recent years) which could explain the favourable conservation status of this population of Greylag Geese in recent years compared to other sympatric wintering goose and swan species.

Evaluation of Nutritional Quality and Sensory Parameters of Meat from Mallard and Four Species of Wild Goose.

Future challenges concerning protein supply for food and feed include the management of all currently available resources. In Sweden, wildfowl are hunted for several reasons, one of which is to protect growing crops. In this study, meat from wild geese and mallard was evaluated with respect to its quality and sensory parameters. The most pronounced sensory differences were between meat from the barnacle goose and the Canada goose and between meat from mallards that were farmed and born wild. This study also provides measurements of values for the nutritional and heavy metal contents of the meat from these wildfowl species in order to elucidate their possible use as modern foods.

Achieving international biodiversity targets: Learning from local norms, values and actions regarding migratory waterfowl management in Kazakhstan.

Migratory species are protected under international legislation; their seasonal movements across international borders may therefore present opportunities for understanding how global conservation policies translate to local‐level actions across different socio‐ecological contexts. Moreover, local‐level management of migratory species can reveal how culture and governance affects progress towards achieving global targets. Here, we investigate potential misalignment in the two‐way relationship between global‐level conservation policies (i.e. hunting bans and quotas) and local‐level norms, values and actions (i.e. legal and illegal hunting) in the context of waterfowl hunting in northern Kazakhstan as a case‐study.Northern Kazakhstan is globally important for waterfowl and a key staging area for arctic‐breeding species. Hunting is managed through licences, quotas and seasonal bans under UN‐AEWA intergovernmental agreements. To better understand the local socio‐ecological context of waterfowl hunting, we take a mixed‐methods approach using socio‐ecological surveys, informal discussions and population modelling of a focal migratory goose species to: (a) investigate motivations for hunting in relation to socio‐economic factors; (b) assess knowledge of species' protection status; and (c) predict the population size of Lesser White‐fronted Geese (LWfG; Anser erythropus; IUCN Vulnerable) under different scenarios of survival rates and hunting offtake, to understand how goose population demographics interact with the local socio‐ecological context.Model results showed no evidence that waterfowl hunting is motivated by financial gain; social and cultural importance were stronger factors. The majority of hunters are knowledgeable about species' protection status; however, 11% did not know LWfG are protected, highlighting a key area for increased stakeholder engagement.Simulations of LWfG population growth over a 20‐year period showed LWfG are highly vulnerable to hunting pressure even when survival rates are high. This potential impact of hunting highlights the need for effective regulation along the entire flyway; our survey results show that hunters were generally compliant with newly introduced hunting regulations, showing that effective regulation is possible on a local level. Synthesis and applications. Here, we investigate how global conservation policy and local norms interact to affect the management of a threatened migratory species, which is particularly important for the protection and sustainable management of wildlife that crosses international borders where local contexts may differ. Our study highlights that to be effective and sustainable in the long‐term, global conservation policies must fully integrate local socio‐economic, cultural, governance and environmental contexts, to ensure interventions are equitable across entire species' ranges. This approach is relevant and adaptable for different contexts involving the conservation of wide‐ranging and migratory species, including the 255 migratory waterfowl covered by UN‐AEWA (United Nations Agreement on the Conservation of African‐Eurasian Migratory Waterbirds).

Ecological divergence of wild birds drives avian influenza spillover and global spread.

The diversity of influenza A viruses (IAV) is primarily hosted by two highly divergent avian orders: Anseriformes (ducks, swans and geese) and Charadriiformes (gulls, terns and shorebirds). Studies of IAV have historically focused on Anseriformes, specifically dabbling ducks, overlooking the diversity of hosts in nature, including gull and goose species that have successfully adapted to human habitats. This study sought to address this imbalance by characterizing spillover dynamics and global transmission patterns of IAV over 10 years at greater taxonomic resolution than previously considered. Furthermore, the circulation of viral subtypes in birds that are either host-adapted (low pathogenic H13, H16) or host-generalist (highly pathogenic avian influenza-HPAI H5) provided a unique opportunity to test and extend models of viral evolution. Using Bayesian phylodynamic modelling we uncovered a complex transmission network that relied on ecologically divergent bird hosts. The generalist subtype, HPAI H5 was driven largely by wild geese and swans that acted as a source for wild ducks, gulls, land birds, and domestic geese. Gulls were responsible for moving HPAI H5 more rapidly than any other host, a finding that may reflect their long-distance, pelagic movements and their immuno-naïve status against this subtype. Wild ducks, long viewed as primary hosts for spillover, occupied an optimal space for viral transmission, contributing to geographic expansion and rapid dispersal of HPAI H5. Evidence of inter-hemispheric dispersal via both the Pacific and Atlantic Rims was detected, supporting surveillance at high latitudes along continental margins to achieve early detection. Both neutral (geographic expansion) and non-neutral (antigenic selection) evolutionary processes were found to shape subtype evolution which manifested as unique geographic hotspots for each subtype at the global scale. This study reveals how a diversity of avian hosts contribute to viral spread and spillover with the potential to improve surveillance in an era of rapid global change.

Multiple lines of evidence of early goose domestication in a 7,000-y-old rice cultivation village in the lower Yangtze River, China

Poultry are farmed globally, with chicken (Gallus gallus domesticus) being the leading domesticated species. Although domestic chicken bones have been reported from some Early Holocene sites, their origin is controversial and there is no reliable domestic chicken bone older than the Middle Holocene. Here, we studied goose bones from Tianluoshan—a 7,000-y-old rice cultivation village in the lower Yangtze River valley, China—using histological, geochemical, biochemical, and morphological approaches. Histological analysis revealed that one of the bones was derived from a locally bred chick, although no wild goose species breed in southern China. The analysis of oxygen-stable isotope composition supported this observation and further revealed that some of the mature bones were also derived from locally bred individuals. The nitrogen-stable isotope composition showed that locally bred mature birds fed on foods different from those eaten by migrant individuals. Morphological analysis revealed that the locally bred mature birds were homogenous in size, whereas radiocarbon dating clearly demonstrated that the samples from locally bred individuals were ∼7,000 y old. The histological, geochemical, biochemical, morphological, and contextual evidence suggest that geese at Tianluoshan village were at an early stage of domestication. The goose population appears to have been maintained for several generations without the introduction of individuals from other populations and may have been fed cultivated paddy rice. These findings indicate that goose domestication dates back 7,000 y, making geese the oldest domesticated poultry species in history.

Molecular characterization, expression profile and transcriptional regulation of the CYP19 gene in goose ovarian follicles.

Cytochrome P450 Family 19 (CYP19) is a crucial enzyme to catalyze the conversion of androgens to estrogens. However, the regulatory mechanism of goose CYP19 gene remains poorly understood. The present study attempted to obtain the full-length coding sequence (CDS) and 5'-flanking sequence of CYP19 gene, to investigate its expression and distribution profiles in different sized follicles, and to analyze the transcriptional regulatory mechanism of CYP19 gene in goose. Results showed that its CDS consisted of 1512 nucleotides and the encoded amino acid sequence contained a classical P450 structural domain. Homology analysis showed that there were high homologies of nucleotide and amino acid sequences between goose and other avian species. Its promoter sequence spanned from -1925bp to the transcription start site (ATG) and several transcriptional factors were predicted in this region. Further analysis from luciferase assay showed that the luciferase activity was the highest spanning from -118 to -1 bp by constructing deletion promoter reporter vector. In addition, result from quantitative real-time polymerase chain reaction indicated that the mRNA level of CYP19 gene were highly expressed in theca layer of the fifth largest follicle, and the cellular location was in the theca externa cells by immunohistochemistry. Taken together, it could be concluded that the transcription activity of CYP19 gene was activated by transcriptional factors in its proximal region of promoter to promote the synthesis of estrogens, regulating the selection of pre-hierarchical into hierarchical follicle in goose.

The ‘Meidum geese’ revisited: Early historical art is not a suitable basis for taxonomic speculation

Romilio (2021) used a taxonomic scoring system to compare differences between three species of geese (Anseriformes) depicted in the Chapel of Itet, one of which he speculated might represent an undescribed (presumably now extinct) species. Despite some apparently distinctive features, the depiction has traditionally been associated with the well-known modern species, red-breasted goose (Branta ruficollis). We discuss limitations in applying the Tobias et al. (2010) scoring system to cases such as this, for which it was not designed, and we outline the many pitfalls that must be considered when attempting to identify historical artwork of birds using examples discussed recently in the ornithological literature. We conclude that the illustrations proposed by Romilio to represent a new Branta goose species are within the range of known plumage variation and potential artistic licence for red-breasted goose, and that this very probably is the species upon which the artwork was based. More generally, we caution against applying the Tobias criteria to cases where a series of specimens cannot be measured, and highlight the difficulties of using illustrations to inform taxonomy.

The Long-Term Monitoring of Bird Populations on Kolguev Island in the Barents Sea

Kolguev Island (69˚05′ N 49˚15′ E) is located in the Pechora Sea, the southeastern part of the Barents Sea. The island’s ecosystem is unusual due to the total absence of rodents and specialized predators such as weasels, while non-specialized predators such as Arctic (Vulpes lagopus) and red (V. vulpes) foxes and Rough-legged Hawk (Buteo lagopus) are common. Currently, 111 bird species have been registered here, of which 58 are nesting. The absence of rodents and the relatively stable predation pressure have resulted in the high abundance of many bird species: Willow Ptarmigan (Lagopus lagopus), several goose species, some waders, and passerines. Over the 125-year history of ornithological studies on Kolguev, the island avifauna has changed significantly. The trend of an increase in the proportion of widespread and Siberian species together with a decrease in the proportion of Arctic species was observed. Since 2006, a thorough monitoring of Kolguev avifauna has been carried out, during which the dynamics of the bird population densities have been traced. The abundance of Black-bellied Plover (Pluvialis squatarola) and Dunlin (Calidris alpina) decreased, while the numbers of Barnacle Goose (Branta leucopsis) have increased sharply since the 1980s. The breeding density of Rough-legged Hawk has also increased in recent years. The long-term monitoring of Kolguev ecosystems has indicated the high international conservation value of the island due to the high breeding density of many bird species. Our study, covering more than a century of avifaunal studies with almost annual monitoring over the past three decades, provides an unusually long and detailed time-series for an Arctic island.

Growth of Greater White‐Fronted Goose Goslings Relates to Population Dynamics at Multiple Scales

ABSTRACTThe abundance of greater white‐fronted geese (Anser albifrons frontalis) on the Arctic Coastal Plain (ACP) of northern Alaska, USA, has more than tripled since the late 1990s; however, recent rate of annual population growth has declined as population size increased, which may indicate white‐fronted geese on the ACP are approaching carrying capacity. We examined rates of gosling growth in greater white‐fronted geese at 3 sites on the ACP during 2012–2014 to assist with predictions of future population trends and assess evidence for density‐dependent constraints on recruitment. We marked goslings at hatch with individually coded webtags and conducted brood drives during early August to capture, measure, and weigh goslings. Annual estimates of gosling mass at 32 days old (range = 1,190–1,685) indicate that goslings had obtained >60% of asymptotic size. This rate of growth corresponds with that of other goose species and populations with access to high‐quality forage and no limitations on forage availability, and is consistent with the overall increase in abundance of white‐fronted geese at the ACP scale. Contrary to most previous investigations, age‐adjusted mass of goslings did not decline with hatch date. Goslings grew faster in coastal areas than at inland freshwater sites. Taken together, these findings suggest forage was not limiting gosling growth rates in either ecosystem, but forage was of greater quality in coastal areas where goose foraging habitat is expanding because of permafrost subsidence. Spatial patterns of gosling growth corresponded with local‐scale patterns of population density and population change; the areas with greatest rates of gosling growth were those with the greatest population density and rates of population increase. We found little evidence to suggest forage during brood rearing was limiting population increase of white‐fronted geese on the ACP. Factors responsible for the apparent slowing of ACP‐wide population growth are likely those that occur in stages of the annual cycle outside of the breeding grounds. Published 2021. This article is a U.S. Government work and is in the public domain in the USA.

Landscape Attributes Best Explain the Population Trend of Wintering Greater White-Fronted Goose (Anser albifrons) in the Yangtze River Floodplain

Biodiversity in the Middle and Lower Yangtze Floodplain has critically decreased during the last several decades, driven by numerous determinants. Hence, identification of primary drivers of animal population decline is a priority for conservation. Analyzing long time-series data is a powerful way to assess drivers of declines, but the data are often missing, hampering effective conservation policymaking. In this study, based on twenty-four years (from 1996 to 2019) of annual maximal count data, we investigated the effects of climate and landscape changes on the increasing population trend of the Greater White-Fronted Goose (Anser albifrons) at a Ramsar site in the Middle and Lower Yangtze Floodplain, China. Our results showed that the availability of a suitable habitat and landscape attributes are the key driving forces affecting the population trend, while the effects of climate factors are weak. Specifically, increasing the area of suitable habitat and alleviating habitat fragmentation through a fishing ban policy may have provided a more suitable habitat to the geese, contributing to the increasing population trend. However, we also observed that the grazing prohibition policy implemented in 2017 at Shengjin Lake may have potentially negatively affected geese abundance, as grazing by larger herbivores may favor smaller geese species by modifying the vegetation community and structure. Based on our results, we suggest several practical countermeasures to improve the habitat suitability for herbivorous goose species wintering in this region.

Phenological mismatch caused by water regime change may explain the population variation of the vulnerable lesser white-fronted goose in east Dongting Lake, China

Phenological mismatches between migratory birds and food availability driven by global warming have been found to influence the fitness and population dynamics of several herbivorous goose species in Arctic breeding sites. However, the effect of phenological mismatches at wintering sites have been inadequately studied. We used long-term data to explore the consequences of water regime changes on phenological mismatch (i.e., days between arrival of geese and timing of the optimal Normalized Difference Vegetation Index [NDVIopt]) and detect the relative role of the mismatch as a driver of annual variations in abundance and distribution of the Lesser White-fronted Goose Anser erythropus (a vulnerable species on the IUCN Red List) in East Dongting Lake, which is the one of this species’ largest wintering sites worldwide. The NDVI of the Carex meadow (i.e., the dominant vegetation in East Dongting Lake wetland and also the major food resource for the geese) was used as the phenology metric. Results showed that the water recession pattern greatly influenced food conditions when geese arrived at the site. Early water recession led to significantly higher NDVI, whereas late water recession led to significantly lower NDVI than did the optimal water recession. However, the suitable habitat area was significantly larger under the optimal water recession pattern. Both early and late water level recessions caused greater mismatches and resulted in lower geese abundance and a more concentrated distribution. NDVI was positively correlated with aboveground biomass and negatively correlated with N% of Carex spp. High biomass and low N% related to high NDVI caused by early water recession may indicate unfavorable food conditions at the time that geese arrive and reduced sustainable food availability in mid-winter, while a low NDVI and limited habitat area caused by late water recession may indicate an insufficient food supply. In conclusion, non-optimal water recession led to a greater phenological mismatch and resulted in limited habitat quality (e.g., lower leaf N%) under early water recession but limited habitat quantity (e.g., smaller habitat area and lower aboveground biomass) under late water recession, and ultimately threatened the Lesser White-fronted Goose. Our results contributed to explaining the decline of the Lesser White-fronted Goose population in this wintering site.

Learning from long time series of harvest and population data: Swedish lessons for European goose management

Goose management in Europe is faced by multiple challenges, as some species are declining and in need of conservation actions, while other populations have become very abundant, resulting in calls for increased harvest. Sweden has long-term series of harvest data and counts of breeding and autumn-staging geese. We used national data (indices) for greylag goose, bean goose and Canada goose to study shifts in temporal trends and correlative patterns, and to infer possible causal links between harvest and population trends. Our study provides an opportunity to guide management given the data collected within the present monitoring, as well as to suggest improvements for future data collection. The populations of greylag and Canada geese increased in Sweden 1979–2018, but this long-term trend included a recent decrease in the latter species. Bean goose breeding index decreased, whilst staging numbers and harvest varied with no clear long-term trend. For Canada goose, our analysis suggests that harvest may affect population growth negatively. For bean goose and greylag goose we could not detect any effect of harvest on autumn counts the following year. We find that the present data and analysis of coherence may suffice as basis for decisions for the current management situation in Sweden with its rather unspecific goals for greylag (very abundant) and Canada goose (invasive species) populations. However, for management of bean geese, with international concerns of over harvest, data lack crucial information. For future management challenges, with more explicit goals, for all goose species we advocate information that is more precise. Data such as hunting effort, age-structure of goose populations and mark–recapture data to estimate survival and population size, is needed to feed predictive population models guiding future Swedish and European goose management.

Influenza A virus surveillance, infection and antibody persistence in snow geese (Anser caerulescens).

Some snow geese (Anser caerulescens) migrate between Eurasia and North America and exhibit high seroprevalence for influenza A viruses (IAVs). Hence, these birds might be expected to play a role in intercontinental dispersal of IAVs. Our objective in this manuscript was to characterize basic incidence and infection characteristics for snow geese to assess whether these birds are likely to significantly contribute to circulation of IAVs. Thus, we 1) estimated snow goose infection prevalence by summarizing>5,000 snow goose surveillance records, 2) experimentally infected snow geese with a low pathogenic IAV (H4N6) to assess susceptibility and infection dynamics and 3) characterized long-term antibody kinetics. Infection prevalence based on surveillance data for snow geese was 7.88%, higher than the infection rates found in other common North American goose species. In the experimental infection study, only 4 of 7 snow geese shed viral RNA. Shedding in infected birds peaked at moderate levels (mean peak 102.62 EID50 equivalents/mL) and was exclusively associated with the oral cavity. Serological testing across a year post-exposure showed all inoculated birds seroconverted regardless of detectable shedding. Antibody levels peaked at 10days post-exposure and then waned to undetectable levels by 6months. In sum, while broad-scale surveillance results showed comparatively high infection prevalence, the experimental infection study showed only moderate susceptibility and shedding. Consequently, additional work is needed to assess whether snow geese might exhibit higher levels of susceptibility and shedding rates when exposed to other IAV strains.

Predicting impacts of food competition, climate, and disturbance on a long‐distance migratory herbivore

AbstractClimate change is driving worldwide shifts in the distribution of biodiversity, and fundamental changes to global avian migrations. Some arctic‐nesting species may shorten their migration distance as warmer temperatures allow them to winter closer to their high‐latitude breeding grounds. However, such decisions are not without risks, since this intensifies pressure on resources when they are used for greater periods of time. In this study, we used an individual‐based model to predict how future changes in food abundance, winter ice coverage, and human disturbance could impact an Arctic/sub‐Arctic breeding goose species, black brant (Branta bernicla nigricans, Lawrence 1846), and their primary food source, common eelgrass (Zostera marina L.), at the Izembek Lagoon complex in southwest Alaska. Brant use the site during fall and spring migrations, and increasingly, for the duration of winter. The model was validated by comparing predictions to empirical observations of proportion of geese surviving, proportion of geese emigrating, mean duration of stay, mean rate of mass gain/loss, percentage of time spent feeding, number of bird days, peak population numbers, and distribution across the complex. The model predicted that reductions >50% of the current decadal (2007–2015) mean of eelgrass biomass, which have been observed in some years, or increases in the number of brant, could lead to a reduction in the proportion of birds that successfully migrate to their breeding grounds from the site. The model also predicted that access to eelgrass in lagoons other than Izembek was critical for overwinter survival and spring migration of brant, if overall eelgrass biomass was 50% of the decadal mean biomass. Geese were typically predicted to be more vulnerable to environmental change during winter and spring, when eelgrass biomass is lower, and thermoregulatory costs for the geese are higher than in fall. We discuss the consequences of these predictions for goose population trends in the face of natural and human drivers of change.

COVID19-induced reduction in human disturbance enhances fattening of an overabundant goose species

Overabundant species can have major impacts on their habitat and induce trophic cascades within ecosystems. In North America, the overabundant greater snow goose (Anser caerulescens atlanticus) has been successfully controlled through special spring hunting regulations since 1999. Hunting is a source of mortality but also of disturbance, which affects the behavior and nutrient storage dynamics of staging snow geese. In 2020, the lockdown imposed by the COVID19 pandemic reduced hunting activity during their migratory stopover in Québec by at least 31%. This provided a unique opportunity to assess the effects of a sudden reduction in hunting disturbance on geese. We used long-term data on body mass combined with movement data from GPS-tracked birds in 2019 and 2020 to assess the effects of the 2020 lockdown on the spring body condition and behavior of greater snow geese. Body condition was higher in 2020 than in all years since the inception of spring hunting in 1999, except for 2019. However, in 2020 geese reached maximal body condition earlier during the staging period than in any other year and reduced by half time spent feeding in highly profitable but risky agricultural habitat in late spring compared to 2019. Although our study was not designed to evaluate the effects of the lockdown, the associated reduction in disturbance in 2020 supports the hypothesis that hunting-related disturbance negatively affects foraging efficiency and body condition in geese. Since spring body condition is related to subsequent breeding success, the lockdown could increase productivity in this overabundant population.

Красноглиняная поливная керамика с изображениями птиц из раскопок Судака (коллекция музея-заповедника «Судакская крепость»)

This paper presents a detailed analysis of the collection of red clay glazed ceramic ware featuring images of birds from the excavations of Sudak and now residing in the Museum Preserve of Sudak Fortress. The publication comprises 45 open-shaped vessels and one ceramic tile. Imported artefacts mostly from the Byzantine circle comprise 22% of them and Crimean products form 78%. Many finds are published for the first time. The products of the Byzantine circle dating back from the thirteenth and fourteenth centuries mostly show a bird of the Accipitridae (probably eagle) and Columbidae. The dove is often depicted with palm branches and/or bunches of grapes which also have important meaning in Christianity. The dove most often occurred on the fourteenth- and fifteenth-century glazed ware ring of Crimean manufacture, where its image was probably associated with Christian symbols and Byzantine tradition. Original drawings of the birds demonstrate individual creativity of local craftsmen since there are many variants of such images. Some drawings allow the one to determine the breed of bird depicted by ceramic painters. Additionally, at the products of Crimean workshops represent at least four other species of birds, presumably swan, bustard, goose or duck, and heron or crane. The research undertaken allowed us to identify a few stylistic decorative series showing bird-shaped images, to discover the origin of artefacts, and to clarify the directions of various cultural influence on local ceramic production.