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Between the early 1900s and the 1990s, the greater snow goose Anser caerulescens atlanticus population grew from 3000 individuals to more than 700 000. Because of concerns about Arctic degradation of natural habitats through overgrazing, a working group recommended the stabilization of the population. Declared overabundant in 1998, special management actions were then implemented in Canada and the United States. Meanwhile, a cost-benefit socioeconomic analysis was performed to set a target population size. Discussions aiming towards attaining a common vision were undertaken with stakeholders at multiple levels. The implemented measures have had varying success; but population size has been generally stable since 1999. To be effective and meet social acceptance, management actions must have a scientific basis, result from a consensus among stakeholders, and include an efficient monitoring programme. In this paper, historical changes in population size and management decisions along with past and current challenges encountered are discussed.

The Eastern Canada (ECA) Flocks data set consists of manually annotated images from the Common Eider (COEI, Somateria mollissima) Winter Survey and the Greater Snow Geese (GSGO, Anser caerulescens atlanticus) Spring Survey. The images were taken in eastern Canada using fixed‐wing aircraft and manually annotated with ImageJ’s Cell counter plugins. We selected and annotated the ECA Flocks images in order to test the precision of the CountEm flock size estimation method. ECA Flocks includes 179 COEI and 99 GSGO single flock images. We cut each image manually to a rectangle that excluded large parts of the image with no birds. Both versions (original and cut) of each image are available in the data set. We manually annotated 637,555 (124,309 COEI and 514,235 GSGO) bird positions in the cut images from both surveys. Each bird has an associated “Type,” which refers to species and/or sex. Sex identification was only possible for adult common eiders, because females and immature males are brown birds, whereas adult males have mainly white plumage. In the COEI images 64,484 males and 58,029 females, as well as 1,796 birds of other species, were identified. In the GSGO images 504,891 Snow Geese and 9,344 birds of other species were labeled. A .csv file including all annotated bird positions and types is available for each image. The COEI and GSGO photos of the ECA Flocks data set were taken in the years 2006 and 2018 and 2016–2018, respectively. We selected these photos in order to include images with different quality and resolution. COEI and GSGO flock sizes range from 6 to 4,154 and from 43 to 36,241 respectively. There is high variability in light conditions, backgrounds, and number and spatial arrangement of birds across the images. The data set is therefore potentially useful to test the precision of methods for analyzing imagery to estimate the abundance of animals by directly detecting, identifying, and counting individuals. We release these data into the public domain under a Creative Commons Zero license waiver. When you use the data in your publication, cite this data paper. Should ECA Flocks be a major part of the data analyzed in your study, you should consider inviting the ECA Flocks originators as collaborators. If you plan to use the ECA Flocks data set, we request that you contact the ECA Flocks core team to learn whether updates are available, and whether similar analyses are already ongoing.

Many of the methods used for estimating population size from ecological surveys have limitations on precision, cost, and/or applicability. The CountEm method was proposed recently for estimating the number of individuals in large groups from single images. It is simple and efficient, and can be applied to any species. Here we present a case study by applying CountEm to a real ecological survey with 278 images of Greater Snow Geese (Anser caerulescens atlanticus) and Common Eiders (Somateria mollissima) flocks taken from fixed‐wing aircraft in Eastern Canada. First, we evaluated the precision and counting time of CountEm on single images. Second, we developed and tested a new multi‐image version of the CountEm software. We show that flock sizes of N > 35,000 can be estimated on single images in ∼5 min, from counting a sample of ∼200 birds, yielding relative SEs in the 5%−10% range. Processing times increased to 10–20 min when simultaneously processing large numbers of images that contained over half a million birds with only modest increases in relative SE (range: 10%−15%). Our results suggest that CountEm may be used to save time and resources if incorporated into monitoring programs that utilize imagery in the abundance estimates.

Several species of loons (or divers; Gaviidae) breed in Arctic Canada, and concern has been raised about their changes in abundance in light of threats such as bycatch and at-sea industrial development. These loons are not well monitored, but we gathered localized count data for three Arctic-nesting loons (Pacific loon Gavia pacifica, red-throated loon G. stellata, and yellow-billed loon G. adamsii) from multiple sources and estimated mean annual population change to estimate species-specific trends over varying time periods. Most breeding ground information between 1996 and 2022 suggested stable numbers for each species, although data were scarce for yellow-billed loon. Trends during the non-breeding season from 1966 to 2021 were estimated for red-throated and Pacific loons from the Christmas Bird Count, a citizen science general bird count, and suggested overall stable or increasing numbers, despite some substantial regional differences. Again, yellow-billed loon numbers were not captured well during the non-breeding season. Aerial winter waterfowl surveys on the east coast of North America (2008–2011, 2014) showed positive trends for red-throated loons for most locations north of 38° latitude and stable trends elsewhere. The paucity of both breeding and non-breeding count data for yellow-billed loons is unfortunate, as this species is found in high numbers in fishing gear in the Arctic. Overall, the limited available data do not suggest that loon populations breeding in the Canadian Arctic have experienced extensive declines, but monitoring of yellow-billed loons should be a priority.

Several driving forces can affect recruitment rates in bird populations. However, our understanding of climate-induced effects or bottom-up vs top-down biological processes on breeding productivity typically comes from small-scale studies, and their relative importance is rarely investigated at the population level. Using a 31-year time series, we examined the effects of selected environmental parameters on the annual productivity of a key Arctic herbivore, the greater snow goose Anser caerulescens atlanticus. We determined the extent to which breeding productivity, defined as the percentage of juveniles in the fall population, was affected by 1) climatic conditions, 2) fluctuations in predation pressure caused by small rodent oscillations, and 3) population size. Moreover, we took advantage of an unplanned large-scale manipulation (i.e. management action) to examine the potential non-lethal carry-over effects caused by disturbance on spring staging sites. The most parsimonious model explained 66% of the annual variation in goose productivity. The spring North Atlantic Oscillation and Arctic snow depth were the primary climatic parameters inversely affecting the production of juveniles, likely through bottom-up processes. Indirect trophic interactions generated by fluctuations in lemming abundance explained 18% of the variation in goose productivity (positive relationship). Mean temperature during brood-rearing and disturbance on staging sites (carry-over effects) were the other important factors affecting population recruitment. We observed a strong population increase, and found no evidence of density-dependent effects. Spatially restricted studies can identify factors linking environmental parameters to local bird reproduction but if these factors do not act synchronously over the species range, they may fail to identify the relative importance of mechanisms driving large-scale population dynamics.

Understanding timing and distribution of virus spread is critical to global commercial and wildlife biosecurity management. A highly pathogenic avian influenza virus (HPAIv) global panzootic, affecting ~600 bird and mammal species globally and over 83 million birds across North America (December 2023), poses a serious global threat to animals and public health. We combined a large, long‐term waterfowl GPS tracking dataset (16 species) with on‐ground disease surveillance data (county‐level HPAIv detections) to create a novel empirical model that evaluated spatiotemporal exposure and predicted future spread and potential arrival of HPAIv via GPS tracked migratory waterfowl through 2022. Our model was effective for wild waterfowl, but predictions lagged HPAIv detections in poultry facilities and among some highly impacted nonmigratory species. Our results offer critical advance warning for applied biosecurity management and planning and demonstrate the importance and utility of extensive multispecies tracking to highlight potential high‐risk disease spread locations and more effectively manage outbreaks.

1. In long-lived species, temporal variation in recruitment, defined as the entry of new individuals into the breeding population, can have a large effect on population growth rate. While hunting, as a management tool, is generally expected to control population size via increased mortality, it may also act by affecting recruitment. Although the impact of hunting on survival is well studied, less attention has been paid to the non-lethal impacts of hunting on recruitment. 2. To control the population size of the greater snow goose Chen caerulescens atlantica, an overabundant arctic-nesting species, a spring hunting season was implemented from 1999 onwards in addition to the traditional autumn and winter hunting seasons. We investigated the potential carry-over effect of spring hunting on recruitment of females to their natal colony on Bylot Island, Nunavut, Canada from 1992 to 2005 while accounting for other potential confounding factors, primarily climatic effects. 3. We applied a multistate capture-mark-recapture recruitment model to a dataset of known-age individuals (n = 12 100), combining live recaptures at the breeding colony with dead recoveries from hunters. 4. Annual variation in recruitment probability was best explained by spring hunt and a synthetic variable combining the climatic conditions experienced during migration (extreme values of the North Atlantic Oscillation index) with conditions upon arrival at the breeding grounds (snow cover). This model accounted for 58% of the temporal variation in recruitment, while the harvest rate or the climatic index taken alone accounted for 38% each. In the year with the highest spring hunting pressure (adult harvest rate ≈6%), recruitment was reduced by up to 50% compared to years with no hunt and similar average climatic conditions. 5. Synthesis and applications. We conclude that there was a negative impact of the spring hunt not only on survival but also on recruitment in greater snow geese. These non-lethal effects of hunting must be considered in management decisions aimed at controlling overabundant populations where recruitment is an important driver of population growth, as occurs in geese. Our study is also relevant to other situations such as in threatened species still exposed to hunting, as consideration of non-lethal effects of hunting may be critical for their conservation.

Understanding the nature of social groups may help explain the genetic structure of populations. Recently, a finescale genetic structure was found in the Greater Snow Goose (Chen caerulescens atlantica) among adults captured in different brood-rearing sites. Such a structure requires assortative pairing among birds coming from the same brood-rearing site, a process that could be enhanced if individuals maintain stable associations over time. We verified whether stable groups persisted throughout the annual cycle of this migratory species. We used an 18-year data set of females marked on brood-rearing sites in the Arctic (n = 16,060) and recaptured on those sites or resighted on the breeding, staging, or wintering grounds in subsequent years. We used a probabilistic method to compare the number of associations observed with the number expected by chance alone. Our results provide no evidence that stable groups persist in flocks during migration or in winter among adult females. However, females marked at the same brood-rearing site had a greater probability of being found nesting together or of being recaptured together on the brood-rearing area in subsequent years than expected by chance. We suggest that the latter associations are more likely due to the fidelity of females to their nesting and brood-rearing site than a consequence of the formation of stable aggregations among individuals. Our results do not support the hypothesis that formation of stable groups is a mechanism that promotes assortative pairing by allowing individuals from the same brood-rearing area to remain together during the non-breeding season in Greater Snow Geese. Comprendre la nature des groupes sociaux peut aider à expliquer la structure génétique des populations. Récemment, une structure génétique à petite échelle spatiale a été mise en évidence chez la Grande Oie des neiges (Chen caerulescens atlantica) parmi des adultes ayant été capturés sur différents sites d'élevage des jeunes. Une telle structure nécessite une préférence pour des individus assortis provenant du même site d'élevage lors du choix d'un partenaire, un processus qui pourrait être facilité si les individus maintiennent des associations stables dans le temps. Nous avons vérifié si des groupes stables persistent lors de la migration annuelle de cette espèce. Nous avons utilisé une base de données s' échelonnant sur 18 ans de femelles marquées sur les sites d'élevage dans l'Arctique (n = 16 060) et recapturées sur ces sites ou réobservées sur les sites de reproduction, de halte migratoire ou d'hivernage dans les années subséquentes. Nous avons utilisé une approche probabiliste pour comparer le nombre d'associations observées au nombre attendu dû au hasard seulement. Nos résultats démontrent aucune évidence que des groupes stables de femelles adultes persistent dans les volées durant la migration ou l'hivernage. Cependant, les femelles marquées sur le même site d'élevage avaient une plus grande probabilité d'être retrouvées nichant ensemble ou d'être recapturées ensembles sur les sites d'élevage les années subséquentes que ce qui aurait été attendu par hasard. Nous suggérons que ces associations sont probablement dues à une fidélité des femelles à leur site de nidification et d'élevage des jeunes plutôt que la conséquence de la formation d'agrégations stables entre les individus. Nos résultats ne supportent pas l'hypothèse que la formation de groupes stables soit un mécanisme facilitant le choix d'un partenaire assorti en permettant aux individus provenant du même site d'élevage de rester ensemble durant tout le cycle annuel chez la Grande Oie des neiges.

During its spring and fall migrations, the Greater Snow Goose ( Chen caerulescens atlanticus ) stages in the marshes along the St. Lawrence Estuary in southern Quebec, where it feeds on three-square bulrush ( Schoenoplectus americanus ) rhizomes. The goose population has grown from 70 000 birds to around one million over the last 40 years, thus increasing pressure on these tidal marshes. To determine the impact of geese on the ecological integrity of the marshes over this period, we used IKONOS satellite imagery and aerial photographs to classify vegetation types. We estimated changes in bulrush cover using the eCognition image analysis software (Trimble). We examined the spectral, textural, and contextual characteristics of the identified classes. The proportion of bulrush cover has declined significantly in the lower marsh since around 1980, and bulrush has been gradually replaced by wild rice ( Zizania aquatica var. brevis ). We also documented the erosion between the lower and upper marshes along most of the shoreline.

\\textcopyright 2015 The Wildlife Society. \\textcopyright The Wildlife Society, 2015.Adaptive management of harvested waterfowl requires accurate estimations of demographic parameters. These must also be representative of the targeted population. In the greater snow goose, all demographic parameters so far have been estimated from long-term banding conducted at a single nesting colony in the Arctic, Bylot Island, where 15% of the population breeds. We used data from a second banding program conducted on Ellesmere Island, 800km north of Bylot Island and near the northern limit of the breeding range, to compare adult survival between these 2 breeding sites over the period 2007-2011. This allowed us to determine the representativeness of demographic parameters estimated from the Bylot colony. We used a multi-event capture-recapture model combining recaptures, resightings of neckbanded birds, and recoveries on a seasonal basis, which allowed us to test specifically for differences in survival during the migration periods. Despite differences in migration distance (20% longer for Ellesmere Island) and environmental conditions, survival rate of birds from these 2 breeding sites were similar in all seasons. Annual survival ranged from 0.72 to 0.79. This apparent absence of a cost of migration on survival may be explained by the canalization hypothesis: variance in adult survival of the greater snow goose, a long-lived species, caused by environmental factors may have been reduced because of selection pressure on this trait, which is closely linked to fitness. The absence of spatial variation in adult survival suggests that the extrapolation of survival parameters estimated from the Bylot Island colony to the entire population may be valid.