Anser Albifrons Research Articles

Contrasting effects of shooting disturbance on the movement and behavior of sympatric wildfowl species.

Human-wildlife conflict is a global conservation issue, necessitating effective mitigation strategies. Hunting is a common management approach to reduce conflict, but the indirect consequences are often overlooked. Chronic hunting-related disturbance can reduce fitness and redistribute species. In recent decades, goose-agricultural conflict has intensified due to increasing abundance and shifts towards agricultural foraging. On Islay, Scotland, escalating conflict culminated in shooting Greenland barnacle geese Branta leucopsis to reduce damage to agricultural grassland. In this study, we contrast the impact of shooting disturbance on the movement, behavior, energy expenditure and habitat selection of the target species (Greenland barnacle goose) and a vulnerable nontarget species (Greenland white-fronted goose, Anser albifrons flavirostris) using biologging devices (target species: n = 33; nontarget species: n = 94). Both species were displaced by shooting, and greater distances were subsequently traveled by the target species (1.71 km when directly targeted). When disturbed at any distance, total daily movement increased significantly by 1.18 km for the target species but not for the nontarget species. The target species exhibited no accompanying change in diurnal energy expenditure (measured via accelerometery) but foraged in improved grasslands further from roads after shooting disturbance, where disturbance from all sources was likely lower. The significant increases in movement and changes in foraging site selection of the target species could reduce fitness but given the infrequency of shooting disturbances (0.09 per day) there is likely capacity for compensatory feeding to recoup energetic losses. The nontarget species expectedly showed no significant change in energy expenditure, behavior or habitat selection following shooting disturbance, suggesting mitigation strategies have been effective at minimizing fitness impacts. Refuge areas with a 3.5 km diameter (three times the maximum distance from shooting that displacement was detectable) could provide undisturbed foraging for the target species, minimizing compensatory feeding and further agricultural damage. Wildlife managers should, where possible, consider the fitness implications of shooting disturbance, and whether compensatory feeding and redistribution could hamper conflict mitigation. Management strategies should also include species-specific monitoring and mitigation as we have demonstrated differing responses potentially due to imposed mitigation but also differing species ecology and "landscapes of fear."

Differential responses to weather and land‐cover conditions explain spatial variation in winter abundance trends in a migratory bird of conservation concern

Abstract Effective conservation strategies for animal populations require knowledge of relationships between population dynamics and their environmental drivers. However, these processes often vary within animal populations, requiring site‐specific conservation planning. Given limited financial resources, identifying groups of sites with similar population dynamics can help practitioners efficiently implement conservation programs to larger areas. We evaluated spatial patterns and environmental drivers of wintering site trends in a migratory bird of conservation concern, the Greenland white‐fronted goose (Anser albifrons flavirostris). We used latent class analysis to identify trend patterns in 35 years of abundance data among 59 geographically discrete Greenland white‐fronted goose wintering sites. We developed a state‐space abundance model in a Bayesian framework to quantify the effects of weather and land‐cover conditions experienced throughout spring migration, summer breeding, autumn migration and wintering periods on variation in wintering site abundance. We identified two main patterns in Greenland white‐fronted goose abundance trends: northeastern wintering sites declined on average by 3% per year, while southwestern wintering sites declined on average by 14% per year. Differential responses to weather and habitat conditions likely explained variation among groups, as geese at southwestern wintering sites were more negatively affected by harsh weather conditions (e.g. low temperatures and high precipitation on breeding areas) and poor habitat conditions (i.e. low‐quality grasslands and croplands) on wintering areas. Future conservation efforts to improve the suitability and nutritional quality of agricultural areas, especially cereal croplands in autumn and early winter and grasslands in late winter and early spring, could potentially improve local habitat conditions, especially in the southwestern wintering sites where abundance declines were steepest. Synthesis and applications. We demonstrate the potential to delineate animal populations based on spatial patterns in population dynamics using long‐term abundance monitoring data, which are commonly the only available data for conservation practitioners. By grouping sites based on spatial patterns in local abundance trends, we can further test hypotheses about how these groups are differentially affected by changing environmental conditions. This information is important for informing efficient conservation planning over large areas when financial resources are limited.

Evidence of longitudinal differences in spring migration strategies of an Arctic-nesting goose.

During spring, migratory birds are required to optimally balance energetic costs of migration across heterogeneous landscapes and weather conditions to survive and reproduce successfully. Therefore, an individual's migratory performance may influence reproductive outcomes. Given large-scale changes in land use, climate, and potential carry-over effects, understanding how individuals migrate in relation to breeding outcomes is critical to predicting how future scenarios may affect populations. We used GPS tracking devices on 56 Greater White-fronted Geese (Anser albifrons) during four spring migrations to examine whether migration characteristics influenced breeding propensity and breeding outcome. We found a strong longitudinal difference in arrival to the breeding areas (18 days earlier), pre-nesting duration (90.9% longer), and incubation initiation dates (9 days earlier) between western- and eastern-Arctic breeding regions, with contrasting effects on breeding outcomes, but no migration characteristic strongly influenced breeding outcome. We found that breeding region influenced whether an individual likely pursued a capital or income breeding strategy. Where individuals fell along the capital-income breeding continuum was influenced by longitude, revealing geographic effects of life-history strategy among conspecifics. Factors that govern breeding outcomes likely occur primarily upon arrival to breeding areas or are related to individual quality and previous breeding outcome, and may not be directly tied to migratory decision-making across broad scales.

Population Dynamics of the White-fronted Goose Anser albifrons (Scopoli, 1769) in the Winter Period in Western Manych in 2018–2023

Population Dynamics of the White-fronted Goose Anser albifrons (Scopoli, 1769) in the Winter Period in Western Manych in 2018–2023

Sunlight and time of the day affect visual lateralisation in Greater White-fronted Geese

Abstract Sensory lateralisation, defined as the separation of functions for processing information from the sensory organs between the hemispheres of the brain, is a variable characteristic of the nervous system influenced by external factors. The plasticity of lateralisation is an important factor influencing the assessment of lateralisation on individual and population levels. We tested the influence of sunlight and time of the day on the visual lateralisation of Greater White-fronted Geese Anser albifrons when following their partners. Most of the individuals showed no preference to observe a partner with one of their eyes. Among the lateralised birds, a significant prevalence of right-eyed individuals was revealed. The highest proportion of lateralised individuals was observed in cloudy conditions. Direct sunlight, particularly in the morning, interfered with the emergence of visual lateralisation. Thus, the effect of sunlight and time of the day on lateralisation in birds should be taken into account when evaluating lateralisation in field observations and experiments.

Visual lateralization in the sky: Geese manifest visual lateralization when flying with pair mates

ABSTRACT The brain’s sensory lateralization involves the processing of information from the sensory organs primarily in one hemisphere. This can improve brain efficiency by reducing interference and duplication of neural circuits. For species that rely on successful interaction among family partners, such as geese, lateralization can be advantageous. However, at the group level, one-sided biases in sensory lateralization can make individuals predictable to competitors and predators. We investigated lateral preferences in the positioning of pair mates of Greater white-fronted geese Anser albifrons albifrons. Using GPS-GSM trackers, we monitored individual geese in flight throughout the year. Our findings indicate that geese exhibit individual lateral biases when viewing their mate in flight, but the direction of these biases varies among individuals. We suggest that these patterns of visual lateralization could be an adaptive trait for the species with long-term social monogamy, high levels of interspecies communication and competition, and high levels of predator and hunting pressure.

Responses of nesting greater white‐fronted geese to oil development in the Arctic

AbstractOil and gas exploration and development is expanding across the Arctic Coastal Plain (ACP) of Alaska, USA. To examine the effects of industrial development on greater white‐fronted geese (Anser albifrons), we monitored nests and nesting behavior within a 4‐km2 study area within 4 km of gravel roads and pads during pre‐development, construction, and operation activities at a new oil development in the National Petroleum Reserve‐Alaska in 2013−2019. We examined distribution, incubation constancy, and nest survival in relation to distance to gravel roads or pads, year and status of development, presence of an ice road the previous winter, and land cover type. Nest density increased throughout the study period, which was consistent with surveys of this species in other regions of the ACP. There was no direct evidence that oil extraction infrastructure and the associated human activity adversely influenced the abundance, distribution, or daily nest survival of greater white‐fronted goose nests. Geese avoided nesting in the alignments of ice roads from the previous winter, and land cover type influenced their nest distribution. Nest age and incubation constancy were important predictors of daily nest survival. The incubation constancy of successful nesters (98.5 ± 0.1% [SE]) was significantly greater than for failed nesters (94.7 ± 0.6%) for all years combined and tended to be greater during the pre‐construction and construction years of 2014 and 2015, compared to when oilfield operations began in 2017 and 2019. Greater‐white fronted geese appear to be tolerant of some levels of industrial activities and the presence of gravel roads did not have a significant effect on nest distribution, incubation constancy, or nest survival. We recommend, however, that indirect effects from ice roads should be explicitly considered in impact assessments because white‐fronted geese avoid nesting in the footprints of the previous winter's ice roads and pads.

Energetic trade-offs in migration decision-making, reproductive effort and subsequent parental care in a long-distance migratory bird.

Migratory species trade-off long-distance movement with survival and reproduction, but the spatio-temporal scales at which these decisions occur are relatively unknown. Technological and statistical advances allow fine-scale study of animal decision-making, improving our understanding of possible causes and therefore conservation management. We quantified effects of reproductive preparation during spring migration on subsequent breeding outcomes, breeding outcomes on autumn migration characteristics and autumn migration characteristics on subsequent parental survival in Greenland white-fronted geese (Anser albifrons flavirostris). These are long-distance migratory birds with an approximately 50% population decline from 1999 to 2022. We deployed GPS-acceleration devices on adult females to quantify up to 5 years of individual decision-making throughout the annual cycle. Weather and habitat-use affected time spent feeding and overall dynamic body acceleration (i.e. energy expenditure) during spring and autumn. Geese that expended less energy and fed longer during spring were more likely to successfully reproduce. Geese with offspring expended more energy and fed for less time during autumn, potentially representing adverse fitness consequences of breeding. These behavioural comparisons among Greenland white-fronted geese improve our understanding of fitness trade-offs underlying abundance. We provide a reproducible framework for full annual cycle modelling using location and behaviour data, applicable to similarly studied migratory animals.

Diet Composition Explains Interannual Fluctuations in Reproductive Performance in a Lowland Golden Eagle Population

Food supply stands out as one of the most critical drivers of population demographics by limiting reproductive rates. In this study, we assessed fluctuations in diet composition and monitored various reproductive parameters over a nine-year period in a Golden Eagle population in an Eastern European peatland. The identification of 2439 prey specimens from 84 species revealed that the studied eagles primarily preyed upon birds (constituting 78.3% of prey numbers and 67.2% of prey biomass) and less on mammals (21.6% and 32.8%, respectively). Grouse emerged as the most important prey group (31% and 27%), followed by waterfowl (17%) and hares (8% and 14%). The most significant prey species, both in terms of numbers and weight, were the Black Grouse, Mountain Hare, Common Crane, and Capercaillie. The share of the Black Grouse decreased, while those of the White-fronted Goose, Roe Deer, and hares increased. The food niche, as measured by the Levins’ index, was broad (6.6), and it expanded during the study. On average, 58.3% of Golden Eagle pairs initiated breeding annually, with 69.1% successfully completing it, and 0.41 young per occupied territory were produced annually; there was pronounced interannual variation in reproductive performance. These fluctuations were associated with the shares of White-fronted Goose, Capercaillie, Mountain Hare and Roe Deer in the diet, suggesting that these species may be gaining increasing importance for the Golden Eagle, particularly following the decline of the Black Grouse.

It takes two to Tango: Plant height and nutrient level determine the diet selection of wintering geese in Poyang Lake, a Ramsar wetland

In Poyang Lake, the largest and one of the most important wintering sites in the East Asian-Australasian Flyway, Carex (Carex cinerascens Kük) meadows provide the primary food source for the wintering geese. However, due to intensified river regulation and more frequent extreme climatic events such as drought, observational evidence suggests that the synchrony of geese migration and Carex phenology could not be maintained without human interventions, imposing a great risk of food shortage during the wintering period. Consequently, the current conservation priority in this Ramsar site is shifted to wet meadow improvement to ensure optimal food quality. Understanding the food preferences of wintering geese is the key for effective wet meadow management. As the growth stage and nutrient level of food plants are the decisive factors influencing the diet selection of herbivores, in this study, we sampled the preferred food items by tracking the foraging paths of the Greater White-fronted Goose (n = 84) and Bean Goose (n = 34) to quantify the “foraging window” in terms of plant height,protein level, and energy content. Further, we established relationships between the above three variables of Carex based on in-situ measurements. The results show that the geese prefer plants with height ranging from 2.4 to 25.0 cm, with protein content from 13.9 to 25.2 %, and energy content from 1440.0 to 1813.6 KJ/100 g. While plant energy content increases with height, the height-protein level relationship is negative. The opposite growth curves signify a conservation challenge to maintain the delicate balance between the quantity and quality requirements of wintering geese. Carex meadow management, such as mowing, should focus on optimizing the timing of action to maximize energy supply while maintaining the right protein level for the long-term fitness, reproduction and survival of the birds.

Comparison of the gut fungal communities among Hooded crane (Grus monacha), Greater white-fronted goose (Anser albifrons), and Bean goose (Anser fabalis) at Shengjin Lake, China

The gut microbes regulate a variety of essential functions in avian hosts. Gut microbes are crucial for understanding avian specie’s ecological role and potential impact on the ecosystem. A wide range of factors shape the gut microbial diversity and communities in avian hosts, including similarity in genotype and shared evolutionary history, particularly in two closely related host species than distinctly related hosts. In this study, high-throughput sequencing methods were applied to compare and study the similarities and differences in the gut fungal communities of two geese from the same genus Anser, Greater white-fronted goose (Anser albifrons, WG), Bean goose (Anser fabalis, BG) with Hooded crane (Grus monacha, HC) sympatric in overlapping niches at Shengjin lake, China. Our findings supported our hypothesis that the two closely related geese shared similar gut fungal alpha diversity patterns compared to Hooded cranes due to similarity in genotype and evolutionary history. In particular, the fungal community composition in the gut of Greater white-fronted goose showed larger variation relative to the other two species. This result suggested that dietary preferences might regulate the gut fungal communities, as Hooded crane and Bean goose share parallel dietary preferences. The results of the abundance null deviation model showed higher values of null deviation (NDV) in Greater white-fronted goose and Bean goose, indicating that the two closely related goose species might be associated with more robust gut filtering for their fungal community relative to Hooded crane species. The fungal co-occurrence networks were complex, with higher stability in the two congeneric geese species relative to Hooded crane. Moreover, 29 animal fungal putative pathogens were identified with high diversity and relative abundance in the two congeneric geese due to their complex migration patterns compared with Hooded cranes. However, due to niche overlap, direct or indirect association may lead to the dissemination of gut microbes among sympatric avian species. These findings have important implications for ecological research, conservation efforts, and wildlife health management. Moreover, these findings illuminate potential ecological and conservation repercussions and increase our understanding of the complex interactions between avian species and their gut flora.

Reducing the number of grazing geese on agricultural fields - Effectiveness of different scaring techniques

Scaring is a widely used damage mitigation tool to make agricultural fields less attractive to wildlife and by that reduce crop damage. However, few experimental studies exist where the numerical response of different scaring devices has been compared. We tested experimentally the effect of three different scaring devices (kite, scarecrow, inflatable man) on the number of geese in fields with cereals, ley, rapeseed, potatoes, and carrots in Sweden. Geese were counted by camera traps and two approaches were used; in a first (model 1) only geese within 50–150m of the scaring devices were counted, and in a second (model 2) all geese in the field were included. A total of 42,281 geese were counted: Greylag goose Anser anser was the most common species (87%), followed by bean goose Anser fabalis (6%), greater white-fronted goose Anser albifrons (3%), barnacle goose Branta leucopsis (2%), and Canada goose Branta canadensis (2%). During scaring the number of geese significantly decreased for all three devices in model 2. The inflatable man decreased goose numbers by 90.0 %, scarecrow 64.6%, and kite 60.5%. A similar pattern was found in model 1, but the decrease was not significant. Our study shows that the scaring devices studied can reduce goose grazing pressure for some time and locally. However, since geese continue to graze during scaring, we conclude that scaring alone is not a final solution to mitigate crop damage. Future work to develop more effective control measures should address the efficiency of other management tools and scaring techniques in combination.

Circulation of Antibiotic-Resistant Escherichia coli in Wild and Domestic Waterfowl in Ukraine.

Background: Antibiotic resistance is becoming an increasingly urgent problem for human and animal health due to the widespread use of antibiotics in medicine, veterinary medicine, and agriculture. At the same time, the natural reservoirs of antibiotic-resistant pathogens remain unclear. Wild birds may play a role in this due to their biology. Escherichia coli is a representative indicator pathogen for antibiotic resistance studies. Materials and Methods: In 2020-2021, sampling of feces and cloacal swabs from six species of wild waterfowl (Eurasian wigeon Anas penelope, Eurasian teal Anas crecca, white-fronted goose Anser albifrons, red-breasted goose Rufibrenta ruficollis, graylag goose Anser anser, shelduck Tadorna tadorna) and from two species of domestic waterfowl (ducks and geese) was conducted in the Kherson, Zaporizhzhia, Odesa, Kharkiv, and Cherkasy regions of Ukraine. Biological material was collected, stored, and transported in cryotubes with transport medium (brain heart infusion broth [BHIB] with the addition of 15% glycerol) in liquid nitrogen. Bacteriological studies were carried out according to standard methods for the isolation and identification of microorganisms. Drug resistance of E. coli was carried out by a standard disk diffusion method. Results: Bacteria representing six families (Enterobacteriaceae, Yersiniaceae, Morganellaceae, Bacillaceae, Pseudomonadaceae, Staphylococcaceae) were isolated from clinically healthy wild birds (wigeon, Eurasian teal, white-fronted goose, red-breasted goose, mallard, graylag goose, shelduck) in the southern regions of Ukraine with isolation rates ranging from 26.7% to 100%. A total of 19 E. coli isolates were cultured from 111 samples from wild birds, and 30 isolates of E. coli were cultured from 32 poultry samples. E. coli was isolated from birds of all species. The prevalence of E. coli ranged from 5.0% to 33.3% in wild waterfowl and from 90.9% to 100% in domestic waterfowl. The prevalence of multidrug-resistant (MDR) E. coli ranged from 10.0% to 31.8% in wild and domestic waterfowl: 3 of 15 (20%) specimens from wild mallard were MDR in the Kherson region, as well as 7 of 22 domestic ducks (31.8%) and 1 of 10 geese (10%) in the Kharkiv and Cherkasy regions. Isolates from wild birds were the most resistant to ampicillin (AMP), amoxiclav (AMC), amoxicillin (AMX), doxycycline (DO), and chloramphenicol (C). Isolates from poultry were resistant to ampicillin, amoxiclav, doxycycline, amoxicillin, chloramphenicol, and enrofloxacin (EX). Most of the other E. coli isolates from wild waterfowl were classified as non-multidrug-resistant (non-MDR) forms. Analysis of antibiotic sensitivity phenotypes showed that only four antibiotic-resistant phenotypes were detected among non-MDR bacteria, whereas among the MDR bacteria, two antibiotic-resistant phenotypes were detected in mallards and six in domestic waterfowl. Conclusion: The results of this study showed that wild waterfowl in Ukraine, which live in natural conditions and do not receive any antimicrobial drugs, are carriers of E. coli that are resistant to a number of antibiotics that are actively used in industrial poultry.

Movement behavior, habitat selection, and functional responses to habitat availability among four species of wintering waterfowl in California

IntroductionHabitat selection analyses provide a window into the perceived value of habitats by animals and how those perceptions compare with other animals, change across time, or change in relation to availability (termed functional responses). Habitat selection analysis and functional responses can be used to develop strategies to avoid habitat limitations, guide habitat management, and set attainable conservation goals. GPS relocations of marked animals are the principal data used in habitat selection analysis. The accuracy and frequency with which tracking devices collect data are increasing and may result in non-stationary point processes that result from latent behaviors previously unidentifiable in sparse data.MethodsWe investigated non-stationary step length distributions and integrated a two-mixture model of animal movement with step selection analysis to identify patterns of activity among four species of co-occurring waterfowl that winter in the Central Valley of California, United States. We evaluated relative strength of selection and compared functional responses across a range of habitat types for two goose and two dabbling duck species.ResultsGoose species (greater white-fronted goose [Anser albifrons] and lesser snow goose [Anser caerulescens caerulescens]) used habitats similarly and displayed similar functional responses with habitat availability. Northern pintail (Anas acuta) displayed functional responses for habitats that provided primary food resources and sanctuary from hunting that were more similar to geese than to mallard (Anas platyrhynchos), which expressed a more generalist pattern of habitat selection.DiscussionOur results define conditions where food resource competition between geese and ducks could operate, which indicate that some species may be more impacted than others. Specifically, early season food limitation may manifest more strongly in snow geese due to longer movements and stronger functional response with rice availability. Late season limitations may manifest in northern pintail, which remain reliant on rice later but may not be reflected in habitat selection patterns due to a consistent functional response with rice availability. We show that multiple movement processes present in high-resolution data can be used to obtain a variety of information about animal behavior and that subsequent step selection analyses may demonstrate unique functional responses relative to alternate habitat selection methods that warrant additional investigation.

Trophic Selectivity of the Barnacle Goose (Branta Leucopsis) and Greater White-Fronted Goose (Anser Albifrons) in Their Reproductive Concentration Area

Trophic Selectivity of the Barnacle Goose (Branta Leucopsis) and Greater White-Fronted Goose (Anser Albifrons) in Their Reproductive Concentration Area

Effects of Habitat Change on the Wintering Waterbird Community in China’s Largest Freshwater Lake

Poyang Lake wetland in the middle and lower Yangtze River floodplain provides important wintering sites for migratory waterbirds. Extreme climatic events and human activities have resulted in the degradation and redistribution of habitat over the last few decades. However, the effects of habitat changes on the abundance of waterbirds remain unclear. We used long-term waterbird monitoring data and Landsat remote-sensing data to characterize changes in abundance and the relationship between habitat variation and abundance. A total of 113 waterbird species were recorded in the wintering period between 1999 and 2021, including 23 globally threatened species. Greater White-fronted Goose (Anser albifrons), Swan Goose (Anser cygnoides), Bean Goose (Anser fabalis), and Tundra Swan (Cygnus columbianus) were the dominant species. A total of 46 species with more than 6 annual surveys and average abundance >100 were recorded between 1999 and 2021. For most species, the mean abundance across all sub-lakes was higher in the first year than in the last year, and no obvious changes were observed over the last 20 years. The mean abundances of the vulnerable species Hooded Crane (Grus monacha) and White-naped Crane (Grus vipio) significantly declined between 1999 and 2021. No significant changes in the mean abundance of all foraging groups were observed. The area of water bodies increased, and the area of mudflats decreased. For most species with significant changes in abundance, habitat change did not greatly contribute to variation in mean abundance. The reduction in the area of mudflats greatly contributed to declines in the mean abundance of the gray heron (Ardea cinerea) and gadwall (Anas strepera).

Trophic selectivity of the barnacle goose and the white-fronted goose in the area of reproductive concentration

Against the backdrop of intense transformation of the Arctic environment and biota, differences in population trends of massive and widespread herbivores in the Arctic are of great interest. In this regard, the main goal of our work was a comparative assessment of the trophic selectivity of the barnacle goose and the white-fronted goose under conditions of the largest reproductive concentration, characterizing the role of competition in the dynamics of their populations. It has been shown that the differences in the quantitative ratio of plants eaten by these species are not sufficient to avoid competition, and that the most selective, i.e. The food of the barnacle goose is sensitive to quality and energy-consuming. However, its status as a relatively weak competitor belies the exponential growth of its population in the study area and the entire Arctic population. We believe that differences in the population dynamics of the barnacle goose and the white-fronted goose are currently not due to competition during reproductive concentrations, but to the influence of anthropogenic and climatic factors far beyond the breeding range.

Temporal and Spatial Evolution of Herbivorous Waterbird Habitat in Floodplain Wetland Driven by Hydrology

AbstractThe hydrological rhythm of floodplain wetlands affected by natural climate variability and human activities is the driving factor affecting the distribution of herbivorous geese habitats. It has always been challenging to determine its long‐term variation, due to the lack of data on species distribution and broad wetland observation. In this study, the key normalized difference vegetation index threshold range suitable for herbivorous geese, greater white‐fronted geese (Anser albifrons, GWG) and bean geese (Anser fabalis, BG), was discovered by combining GPS tracking data with Landsat satellite data. The suitable habitat area and distribution variation characteristics of GWG and BG from 1982 to 2020 were extracted based on the threshold range. The results showed that the suitable habitat area had a declining trend after 2003, that the distribution had moved toward the lake's center, and that its average elevation had decreased by around 1 m, particularly during the arrival period. The change of herbivorous geese habitat is caused by the continuous drying of Poyang Lake. The study can offer a rational scientific foundation for wetland waterbird protection and watershed hydrological management.

Food on a plate: Wild geese maintain higher food intake rates on uniform winter cereals fields versus diverse grasslands

Spring staging Greater White-fronted Geese Anser albifrons have increasingly shifted from traditional diverse grassland fields to monocultures of winter cereals, causing conflict with farmers. To account for this transition, we tested two key predictions, controlling for goose age effects and sward height. Firstly, that cereal is better quality than grass (based on crude protein content). Secondly, that geese show higher peck rate and step rate on grassland than cereal, enabling them to compensate for lower, less selective intake rates there compared to the uniform, dense, high quality arable sward where all blades are equally of high profitability. Laboratory analyses showed that winter cereal had 27 % higher crude protein content than grass. Based on data extracted from video sequences of spring foraging geese in NE Poland, first-year birds (“immatures”) showed significantly higher peck rates and step rates than adults in all situations, likely reflecting their less efficient foraging abilities. Both age classes showed significantly higher peck rates on grass than winter cereal as predicted. Combining differential protein content and lamina length/dry weight relationships of grass versus cereal showed that geese obtained 17–33 % more protein from cereal lamina of the same length. At observed peck rates, this equated to a 6 % greater hourly crude protein intake rate on cereals compared to grass at lamina length 2.5 cm, increasing to 29 % difference at 12.5 cm. Hence, at longer swards, cereals become increasingly profitable for foraging geese over grass swards, despite the higher peck rates observed on grass which failed to compensate for lower lamina quality. We contend that these interactions explain the simultaneous attraction of cereal over grass swards in this study area and likely elsewhere and we discuss the management implications of these findings.

Differing drivers of decline within a migratory metapopulation has implications for future conservation.

Researchers generally ascribe demographic drivers in a single sub-population and presume they are representative. With this information, practitioners implement blanket conservation measures across metapopulations to reverse declines. However, such approaches may not be appropriate in circumstances where sub-populations are spatiotemporally segregated and exposed to different environmental variation. The Greenland White-fronted Goose, Anser albifrons flavirostris, is an Arctic-nesting migrant that largely comprises two sub-populations (delineated by northerly and southerly breeding areas in west Greenland). The metapopulation has declined since 1999 but this trend is only mirrored in one sub-population and the causes of this disparity are unclear. Here we compare the drivers and trends of productivity in both sub-populations using population- and individual-level analysis. We examined how temperature and precipitation influenced population-level reproductive success over 37 years and whether there was a change in the relationship when metapopulation decline commenced. In addition, we used biologging devices to remotely classify incubation events for 86 bird-years and modelled how phenology and environmental conditions influenced individual-level nest survival. Correlations between reproductive success and temperature/precipitation on the breeding grounds have weakened for both sub-populations. This has resulted in lower reproductive success for the northerly, but not southerly breeding sub-population, which at the individual-level appears to be driven by lower nest survival. Earlier breeding ground arrival and less precipitation during incubation increased nest survival in the northerly breeding population, while no factors examined were important for the southerly breeding sub-population. This suggests reproductive success is driven by different factor(s) in the two sub-populations. Demographic rates and their environmental drivers differ between the sub-populations examined here and consequently we encourage further decomposition of demography within metapopulations. This is important for conservation practitioners to consider as bespoke conservation strategies, targeting different limiting factors, may be required for different sub-populations.