Goose Population Research Articles

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.

Seeking greener pastures: crop selection by Greylag Geese (Anser anser) during the moulting season

Over the last 40 years, many goose populations have recovered from historic lows and are now more numerous than ever. At the same time, geese have shifted from natural foraging habitats to securing most of their nutritional demands from agricultural fields, leading to crop damage and conflict with agriculture. We studied field use by Greylag Geese (Anser anser) in the agricultural landscape surrounding a main breeding and moulting lake in Sweden. From 2012 to 2016, weekly roadside surveys were conducted from May to July. Data were collected on goose numbers, crop type and sward height in agricultural fields. Using a compositional analysis, we demonstrate that Greylag Geese show a strong selection for ley and pasture fields compared to other crop types (rank order: ley/pasture > oat > barley > wheat > other crops). This selection was consistent across years and between pre- and post-moult. Aside from ley and pasture, no other crop types were selected for, as they were used less than expected given their availability. Irrespective of crop type, geese foraged predominantly on short (0–10 cm) swards. The strong selection for ley and pasture may have been driven by higher nutritional quality of short, managed grass swards relative to other available foods. This suggests that during the summer grass fields may be more vulnerable to damage compared to other crop types. Our study provides a deeper understanding of the ecology of Greylag Geese, which may be used to inform management strategies focused on mitigating crop damage and alleviating conflict.

Setting population-size targets for geese causing socio-economic conflicts

Most European goose populations have increased exponentially, and this has increasingly brought them into conflict with human activities. To manage this conflict, we used multi-criteria decision analysis to help set population targets for a super-abundant population of greylag geese (Anser anser). We relied on expert elicitation to assess the consequences of varying goose abundance on nine ecological, economic, and societal objectives. Representatives from national governments and from non-governmental organizations then weighted the objectives based on their perceived relative importance, and we used a consensus-convergence model to reach stakeholder agreement on the tradeoffs among objectives. The preferred population targets for two management units represent about a 20% reduction from current abundances, which from a management perspective would require considerable effort above and beyond current population-control measures. We believe that multi-criteria decision analysis can provide a systematic and transparent framework for building consensus among diverse stakeholders in a wide array of human-wildlife conflicts.

Distribution and Population Size of Emperor Geese during the Breeding Season on the Seward Peninsula, Alaska

The Emperor Goose (Anser canagicus) is a year-round occupant of northern latitudes, spending its entire annual cycle in coastal habitats of western Alaska and the Russian Far East. Over the last several decades, the Emperor Goose population underwent a pronounced decline, prompting 30 consecutive years of harvest closures, followed by a protracted recovery and the recent reopening of harvest. This recovery was primarily documented on the Yukon-Kuskokwim Delta in western Alaska, where an estimated 80% – 90% of the world’s Emperor Goose population breeds. However, the size and status of their population on the Seward Peninsula, Alaska, which is their only other significant breeding area in North America, remains almost completely unknown. Therefore, to better inform population and harvest management of Emperor Geese in western Alaska, we conducted extensive aerial surveys of Emperor Geese along the northern coast of the Seward Peninsula during the breeding season. During the summer of 2018, we surveyed 150 transects totaling 351 km2, for a total sampled fraction of 7.2% of the 4853 km2 survey area. Using a double-observer technique that accounted for detection probability, we estimated a population of 1226 (95% CI: 792 – 1660) Emperor Geese on the Seward Peninsula, of which 614 (95% CI: 416 – 811) were considered breeding birds based on their observed status as singles or pairs. Most Emperor Geese (61%) were found on barrier islands, even though these islands accounted for just 3.5% of the total survey area; the remaining geese were found in lowland coastal habitats (23%) or upland tundra (16%). Overall, our surveys indicate a small breeding population of Emperor Geese on the Seward Peninsula, which raises some conservation concern. Further reductions or extinction of this small population would leave Emperor Geese with only one significant breeding area in North America. Because Emperor Geese typically display high breeding site fidelity and female natal philopatry, any future growth of this small population will likely to need to come from within.

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.

Ecology and population structure of some indigenous geese breeds and the impact of four GH and Pit-1 SNPs on their body weights.

This study aims to determine the genetic correlation using nine microsatellite markers to reconstruct the history of some indigenous geese populations, along with the use of four single nucleotides polymorphisms (SNPs) to investigate their correlation with the geese body weight. Microsatellite markers are mainly used to provide updated information on changes in the population structure of geese breeds. The eight goose populations reported 24% private alleles specific for each population. Expected heterozygosity (He) ranged from 0.46 to 0.70. Three breeds were reported highly polymorphic. Inbreeding coefficient (Fis) revealed that three breeds were in a minimum level of extinction danger, while one breed was in a potential endangered situation. Phylogenetic tree, principal component analysis (PCA), and self-organizing map (SOM) were constructed using MATLAB to study the population distribution and relationship among these breeds. Four SNPs were detected, two SNPs at GH gene exon (C123T and C158T), and two SNPs at Pit-1 gene exons (G161A and T282G). Four SNP loci were reported to have a significant effect on geese body weight. They were CT genotype for C123T locus, TT genotype for C158T locus, GG genotype for G161A locus, and GG genotype for T282G locus.

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.

Genomic characteristics of four different geese populations in China.

It is well known that many Chinese goose breeds differ substantially in economic performance, but the genetic changes involved are still poorly understood. This study sequenced 35 individuals from four goose breeds namely Shitou, Zhedong White, Taihu, and Zi with an average sequencing depth of 10× for each individual. Among these populations, SNPs were identified, which clustered the individuals into four distinct genetic groups in accordance with the four breeds. Genomic comparisons among the four goose breeds revealed many candidate genes, as well as pathways that may be associated with meat yield in Shitou geese and laying traits in Zi geese. These findings will enable a better understanding of the artificial selection history of Chinese local geese and provide a valuable resource for future research on the breeding of geese for the economic traits of meat and egg production.

Development of Microsatellite Marker System to Determine the Genetic Diversity of Experimental Chicken, Duck, Goose, and Pigeon Populations.

Poultries including chickens, ducks, geese, and pigeons are widely used in the biological and medical research in many aspects. The genetic quality of experimental poultries directly affects the results of the research. In this study, following electrophoresis analysis and short tandem repeat (STR) scanning, we screened out the microsatellite loci for determining the genetic characteristics of Chinese experimental chickens, ducks, geese, and pigeons. The panels of loci selected in our research provide a good choice for genetic monitoring of the population genetic diversity of Chinese native experimental chickens, ducks, geese, and ducks.

Determination of Consumer Preferences for Goose Meat Using Conjoint Analysis

This study examines the consumer preferences for goose meat purchases of consumers who had previously purchased goose meat. The main purpose of this study is to determine which factors are more important for consumers when purchasing goose meat. Accordingly, the conjoint analysis technique, which is one of the multivariate statistical analysis methods, is used to determine the factors affecting goose meat purchases and the reasons for preferring goose meat. According to data of the Turkish Statistical Institute (TURKSTAT) for 2019, 44.07% of the goose population of Turkey (1,157,049) spread among the provinces of Kars (27.26%), Ardahan (8.68%), and Mus (8.13%). A sample of 172 people was selected by using the convenience sampling technique, one of the non-probability sampling methods, among the people who lived or have been living in these provinces and consumed goose meat. Market research and a questionnaire, which was prepared to determine consumer preferences, were conducted on this sample. According to the results of the analysis, the most significant factor determining the consumer preference for goose meat was found to be the price of goose meat per kilo (37.3%). This was followed by the region where the goose was raised (32.8%), the place where the goose meat was sold (21.6%), and the presence of the product label (8.3%) with the identification information of the product. Considering the results of the data obtained from the study, it is thought that the market share of the goose meat will increase if its recognition is increased by applying a reasonable pricing strategy, and standardizing the quality of the product.

Long-term consequences of goose exclusion on nutrient cycles and plant communities in the High-Arctic

Geese can profoundly affect arctic ecosystems directly (e.g., by grazing vegetation) and indirectly (e.g. by changing nutrient cycling resulting from faces inputs and by reducing plant litter). In the Arctic, behavior and abundance of geese have changed due to climate and land-use change. While the short-term effects of increased goose populations on tundra ecosystems are known, there is a knowledge gap for long-term consequences of goose population changes on nutrient cycling and plant communities, especially in the High-Arctic. Here, we compared wetland sites where geese have been almost absent for at least 50 years (Pond Inlet), and nearby sites where geese are abundant or sites where they have been excluded experimentally by cages and where the ground has been experimentally fertilized for over 16 years (Bylot Island). Long-term goose disappearance increased inorganic nutrients in wetlands through increased plant litter decomposition and changed community composition, likely by altering competitive relationships between three dominant vascular plant species that are different in terms of nutrient acquisition and use. In experimentally fertilized sites, inorganic nutrients were similarly increased, but fertilization had contrast effects on plant community composition compared with herbivory, released plant species from the nutrient limitation and converted wetland habitats to a dryer state. Overall, our results suggest that the direct effects of goose herbivory on vegetation are more profound than their indirect effects through an alternation of nutrient cycling even in nutrient-limited wetlands of the Arctic. These findings emphasize the need to assess long-term direct impacts of herbivores on vegetation.

Evaluation of the genetic diversity of some rare geese breeds based on microsatellite markers

Abstract Microsatellites were utilized to determine the genetic diversity and estimate the relationship between 9 goose populations. A total of 58 unique alleles were found in all 9 populations, and the allele frequency ranged from 0.71% (Toulouse breed: TOU) to 18.33% (local Egyptian breed of grey colour: LB1). The effective number of alleles ranged from 2.04 (Wanxi breed: WX) to 5.36 (Emden breed: EMED), observed heterozygosity ranged from 0.37 (WX) to 0.62 (EMED), and expected heterozygosity was reported in the range of 0.43 (WX) to 0.7 (EMED). The results revealed highly polymorphic content of the tested loci, with three populations [WX, Sichuan breed (SC), Zhejiang breed (ZHE)] reported to be slightly polymorphous. Within the 9 populations, breeding coefficient (Fis) ranged from 0.03 (EMED) to 0.26 (WX). The phylogenetic tree showed two clades: the first clade contained LB1 and the three Chinese breeds (ZHE, WX, SC), while the second clade contained the local Egyptian breed of white colour (LB2) and Pilgrim breed (PIL) and the three western breeds [Roman tufted breed (ROT), TOU, EMED]. Only three populations showed distinct boundaries at clustering (SC, ZHE, WX), which was found by structure analysis. Principal coordinates analysis 2D and 3D scatter plots were constructed for distinct population structure distribution results, confirming the geographical distribution of the breeds. The deviation of the principal coordinates’ analysis from the F 1 axis was 54.01% and from F 2 was 15.37%. Finally, self-organised map node arrangements represented the relationship and the interaction between different populations, providing an idea about the population structure of rare and indigenous goose breeds, especially the two Egyptian local breeds LB1 and LB2. The aim of this study was to determine genetic diversity and genetic correlation using 9 microsatellite markers in order to explore the breeding history of the investigated rare goose breeds, to provide data on changes in population structure, and to provide the basis for the development of appropriate plans to improve population growth for respective environmental needs with some emphasis on the conservation of genetic resources.

Increased immune marker variance in a population of invasive birds

Immunity and parasites have been linked to the success of invasive species. Especially lower parasite burden in invasive populations has been suggested to enable a general downregulation of immune investment (Enemy Release and Evolution of Increased Competitive Ability Hypotheses). Simultaneously, keeping high immune competence towards potentially newly acquired parasites in the invasive range is essential to allow population growth. To investigate the variation of immune effectors of invasive species, we compared the mean and variance of multiple immune effectors in the context of parasite prevalence in an invasive and a native Egyptian goose (Alopochen aegyptiacus) population. Three of ten immune effectors measured showed higher variance in the invasive population. Mean levels were higher in the invasive population for three effectors but lower for eosinophil granulocytes. Parasite prevalence depended on the parasite taxa investigated. We suggest that variation of specific immune effectors, which may be important for invasion success, may lead to higher variance and enable invasive species to reduce the overall physiological cost of immunity while maintaining the ability to efficiently defend against novel parasites encountered.

Risk of Urban Zoonosis from Geese Colonized with Antimicrobial Resistant Bacteria

Abstract Introduction/Objective Zoonotic disease occurs through direct fecal contact with increased exposure resulting in higher infection rates. Antimicrobial resistant colonization occurs in wild birds, however the spread of microbial resistance correlates with increased human activity. Anchorage actively develops urban park environments with pastoral lawns and abundant water sources creating an inviting habitat for human and geese populations. By 2018, Alaska Fish and Game reported a 10-fold increase in migrating Canadian Geese resulting in significant environmental damage, including fecal contamination. At the same time, Anchorage experienced an uptake use of their parks and costal trails for both recreation and homeless camps. To determine potential exposure, sixty-eight geese fecal samples were collected in fourteen urban park locations. Methods Fecal samples were incubated in thioglycolate broth at 37oC for 24 hours then cultured to chromogenic screening agar for vancomycin resistant enterococcus (VRE), methicillin resistant Staphylococcus aureus (MRSA), and extended spectrum beta-lactamase (ESBL) enterobacteriaceae. Potential MRSA, VRE or ESBL colonies were further identified using standard biochemical testing with confirmation of antimicrobial resistance by disk diffusion. Results Forty percent of all fecal samples collected were colonized with VRE or ESBL producing Escherichia coli with eighty-six percent of collection sites positive for one or more antimicrobial resistant bacterium. Seven percent of fecal samples were positive for both organisms. MRSA was not identified. The highest concentration of antimicrobial resistant bacteria was discovered on the Campbell Creek Trail (83%), which winds alongside Providence Hospital. Conclusion Transmission of infectious agents can occur due to environmental exposure, which increases in individuals who are either housing insecure or chronically homeless. Urban green spaces are often sites for unregulated camping by individuals who lack consistent residential housing. Discovery of antimicrobial resistant colonization in geese populating nearly ninety percent of Anchorage’s parks and trails creates a significant public health issue, with the homeless population targeted for poor outcome due to their immunocompromised status. Continued evaluation is essential to predict infection risk and impact on healthcare delivery, especially in vulnerable populations.

Experimental evidence for conservation conflict interventions: The importance of financial payments, community trust and equity attitudes

Abstract Conflicts between the objectives of agricultural production and conservation are becoming increasingly complex. Of vital importance to the success of conflict interventions is a detailed understanding of how stakeholders react to management interventions as well as the influence of interacting social and political factors. Across Europe, goose populations have increased considerably, leading to widespread impacts on agriculture and significant conflicts between different stakeholder groups. We used a novel experimental game to understand farmer preferences regarding the design of goose conflict interventions in Scotland. We specifically examined how three alternative interventions (government financial support for scaring activities, subsidies and agglomeration payments that include bonus payments for adoption by neighbouring farms) affect farmer propensity to support goose conservation interests through reduced shooting and the provision of sacrificial crops. We also examined the links between within‐game behaviour and real‐life attributes and attitudes of farmers. We found that all three interventions were conducive to pro‐conservation behaviour in the games. The effects of all three interventions were stronger among farmers who had higher trust towards other community members. Agglomeration payments led to increased provision of sacrificial crops among farmers with negative attitudes towards the current allocation of goose finances in Scotland. Farmers with more positive attitudes towards wildlife tourism were more likely to provide more sacrificial crops, and less likely to shoot in the games. Farmers' real‐life traits had a statistically significant but marginal impact on the effectiveness of financial payments, such as the number of geese being shot on their own lands, remoteness and crop damage by geese. These game results provide evidence for the potential of innovative financial instruments in conflict management and their interactions with social factors such as community trust, equity attitude and real‐life shooting levels. Our study highlights the importance of socio‐political elements in fostering mutually beneficial outcomes in conservation conflicts in addition to addressing material losses to wildlife. We also show how games can help in addressing conservation conflicts in a wide range of settings. A free Plain Language Summary can be found within the Supporting Information of this article.

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.

Temperature and precipitation at migratory grounds influence demographic trends of an Arctic-breeding bird.

Anthropogenic climate disruption, including temperature and precipitation regime shifts, has been linked to animal population declines since the mid-20th century. However, some species, such as Arctic-breeding geese, have thrived during this period. An increased understanding of how climate disruption might link to demographic rates in thriving species is an important perspective in quantifying the impact of anthropogenic climate disruption on the global state of nature. The Greenland barnacle goose (Branta leucopsis) population has increased tenfold in abundance since the mid-20th century. A concurrent weather regime shift towards warmer, wetter conditions occurred throughout its range in Greenland (breeding), Ireland and Scotland (wintering) and Iceland (spring and autumn staging). The aim of this study was to determine the relationship between weather and demographic rates of Greenland barnacle geese to discern the role of climate shifts in the population trend. We quantified the relationship between temperature and precipitation and Greenland barnacle goose survival and productivity over a 50year period from 1968 to 2018. We detected significant positive relationships between warmer, wetter conditions on the Icelandic spring staging grounds and survival. We also detected contrasting relationships between warmer, wetter conditions during autumn staging and survival and productivity, with warm, dry conditions being the most favourable for productivity. Survival increased in the latter part of the study period, supporting the possibility that spring weather regime shifts contributed to the increasing population trend. This may be related to improved forage resources, as warming air temperatures have been shown to improve survival rates in several other Arctic and northern terrestrial herbivorous species through indirect bottom-up effects on forage availability.

Increased rice flooding during winter explains the recent increase in the Pacific Flyway White‐fronted GooseAnser albifrons frontalispopulation in North America

Despite declines in numerous migratory bird populations due to global climate and landscape changes, the Pacific Flyway population of Greater White‐fronted GeeseAnser albifrons frontalisin North America has flourished over recent decades. However, the demographic foundations of the population increase remain unclear, largely due to sparse data. In this study, we used a Bayesian integrated population model (IPM) to maximize information from multiple data sources including coordinated population survey, ring‐recovery and hunter‐harvested goose tail data. We estimated demographic parameters and assessed the role of several possible drivers of the observed population increase, including density‐dependent processes, agricultural land use change and climate conditions in both the wintering and the breeding season, while also accounting for the impacts of harvest. Non‐harvest survival of all geese was 0.83 (95% credible interval (CRI): 0.70–0.96) before legislation restricted post‐harvest rice field burning, and 0.98 (95% CRI: 0.94–1.0) afterwards. We detected a negative effect of density‐dependent processes and a positive effect of El Niño‐Southern Oscillation on non‐harvest survival with high certainty. Kill rates were 0.11 (95% CRI: 0.09–0.12) for adults (after hatch year) and 0.26 (95% CRI 0.21–0.31) for juveniles (hatch year), resulting in annual survival rates of 0.81 (95% CRI: 0.69–0.89) for adults and 0.67 (95% CRI: 0.56–0.76) for juveniles. The ratio of juvenile birds to adults in the population was on average 0.36 (95% CRI: 0.29–0.45) and was driven by negative density‐dependent processes with high certainty. Our results suggest that the ban on rice field burning and subsequent high frequency of flooding as an alternative rice decomposition practice was the primary driver of the Pacific white‐fronted Goose population increase. The effects of climate change and density dependence were not strong enough to suppress the benefit of flooded rice. Given sparse demographic data for Pacific white‐fronted Geese, we were only able to uncover drivers of demography using IPMs. We encourage practitioners with sparse data similarly to consider forming IPMs to determine the drivers and mechanisms for population change and to prioritize future data collection.

Molecular cloning of the goose GnRH gene and identification of GnRH polymorphisms associated with laying traits

ABSTRACT 1. Egg-laying traits are important economic characteristics in goose production (Anser cygnoides). The gene GnRH, which encodes gonadotropin-releasing hormone, is a strong candidate gene for egg-laying traits in avian species. 2. In this study, a 3520 bp genomic sequence and a 279 bp mRNA sequence for GnRH, which encoded 92 amino acids, were determined. The GnRH DNA sequence contains four exons and three introns, and the DNA and deduced amino acid sequences were highly conserved across mammals (human, macaque, cow, and sheep) and avians (chicken, fulmar and quail). 3. Using a direct sequencing method, 46 single nucleotide polymorphisms (SNPs) were identified in the GnRH genomic sequence that were shared between two Sichuan White goose populations (217 and 208 individuals). Furthermore, 44 haplotypes were constructed using a sliding window approach. Association analysis between the SNPs and haplotypes and egg-laying traits showed that 10 SNPs affected the first egg weight, average egg weight, egg number at 48 weeks and egg number at 64 weeks. 4. These results lay the foundation for further studies of the function of GnRH in geese and provide a theoretical basis for marker-assisted selection of egg-laying traits in the Sichuan white goose population.

Molecular cloning and variant analysis of the TSHR gene in goose (Anser cygnoides)

ABSTRACT 1. The thyroid-stimulating hormone receptor (TSHR) is a glycoprotein hormone receptor which has a pivotal role in metabolic regulation and photoperiod control during reproduction in birds and mammals. However, the molecular characterisation of TSHR in goose is unknown. 2. The goose TSHR cDNA (TSHR-1) is 2334 bp in length and encodes a protein of 763 amino acids. This trial identified another three novel splice variants of goose TSHR, TSHR-2 (lacking the exon 3 in TSHR-1 transcript), TSHR-3 (lacking the exon 6 in the TSHR-1 transcript) and TSHR-4 (lacking 12 bp of exon 8 and the entire exon 9 in the TSHR-1 transcript). 3. Bioinformatics analysis indicated that all the deduced TSHR amino acid sequences contained seven putative transmembrane domains, and the TSHR-3 protein lacked one potential N-linked glycosylation site (N-E-S) compared to the other three deduced proteins. 4. A phylogenetic tree based on amino acid sequences showed that the goose TSHR protein was closely related to those of other avian species, especially duck and chickens. 5. One microsatellite and three single nucleotide polymorphisms (SNPs) were identified. For the c1109A/G locus, AA and GA genotypes were found in the Zhedong-White goose population, GG and GA genotypes were detected in the Landes goose population, but the AA genotype was only detected in the other four goose populations. 6. All the information derived from this study can facilitate further studies on the functions of the goose TSHR gene.