Barnacle Geese Branta Leucopsis Research Articles

More management, less damage? With increasing population size, economic costs of managing geese to minimize yield losses may outweigh benefits

Conflicts between farmers and geese are intensifying; yet, it remains unclear how interactions between goose population size and management regimes affect yield loss and economic costs. We investigate the cost-effectiveness of accommodation and scaring areas in relation to barnacle goose (Branta leucopsis) population size. We use an existing individual-based model of barnacle geese foraging in nature, accommodation, and scaring areas in Friesland, the Netherlands, to study the most cost-effective management under varying population sizes (i.e., between 20 and 200% of the current size). Our study shows that population size non-linearly affects yield loss costs and total costs per goose. The most cost-effective management scenario for intermediate to large populations is to avoid scaring of geese. For small populations, intensive scaring resulted in minimized yield loss costs and total costs, but also substantially lower goose body mass. Our results strongly suggest that scaring becomes a less effective management measure as goose populations increase.

Low spatial habitat overlap of herbivores in the High Arctic tundra

Herbivores play a crucial role in shaping tundra ecosystems through their effects on vegetation, nutrient cycling, and soil abiotic factors. Understanding their habitat use, co-occurrence, and overlap is therefore essential for informing ecosystem-based management and conservation. In the High Arctic, only a marginal proportion of the land area is vegetated, and climate change is impacting herbivore population sizes and their habitats. In this study, we assessed the spatial habitat overlap of a vertebrate herbivore community based on: 1) regional predictive summer habitat suitability models for the resident Svalbard reindeer (Rangifer tarandus platyrhynchus), resident Svalbard rock ptarmigan (Lagopus muta hyperborea), and the migratory pink-footed goose (Anser brachyrhynchus), and 2) presence of fecal pellets, reflecting the annual habitat use of reindeer, ptarmigan, and geese, including the pink-footed goose and barnacle goose (Branta leucopsis). Our findings revealed that only small proportions of the available land cover (∼ 12,516 km2; all land area excluding glaciers and freshwater) are suitable for each of the species (habitat suitability [HS] > 0.5): reindeer (22 %), ptarmigan (11 %), and pink-footed goose (4 %). Overlapping suitable habitat [HS > 0.5] for reindeer and goose accounted for only 3 % of the total vegetated area (∼ 8848 km2) and was primarily found in heath and moist habitats dominated by mosses, graminoids, and herbaceous plants. The overlapping suitable habitat for reindeer and ptarmigan covered 8 % of the vegetated area, in higher elevation ridges with vegetation on drier substrates. The shared habitat for ptarmigan and goose, and all three species of herbivores, was less than 1 % of the vegetated area. Additionally, an assessment of fecal pellets suggested that the highest overlap in habitat use among reindeer and goose occurred in bird cliff moss tundra, followed by moss tundra and heath habitats. The small proportion of the vegetated area suitable for all three herbivores indicates a high degree of habitat differentiation. Therefore, different habitats need to be considered for the management and conservation of resident and migratory herbivore species in this High Arctic Archipelago. Moreover, our results underscore the importance of the small but productive parts of the landscape that were used by all herbivores.

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.

Baltic Population of the Barnacle Goose (Branta leucopsis (Bechstein 1803)) in the Boreal Zone of Northwestern Russia

Baltic Population of the Barnacle Goose (Branta leucopsis (Bechstein 1803)) in the Boreal Zone of Northwestern Russia

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

Long‐term herbivore removal experiments reveal how geese and reindeer shape vegetation and ecosystem CO2‐fluxes in high‐Arctic tundra

Abstract Given the current rates of climate change, with associated shifts in herbivore population densities, understanding the role of different herbivores in ecosystem functioning is critical for predicting ecosystem responses. Here, we examined how migratory geese and resident, non‐migratory reindeer—two dominating yet functionally contrasting herbivores—control vegetation and ecosystem processes in rapidly warming Arctic tundra. We collected vegetation and ecosystem carbon (C) flux data at peak plant growing season in the two longest running, fully replicated herbivore removal experiments found in high‐Arctic Svalbard. Experiments had been set up independently in wet habitat utilised by barnacle geese Branta leucopsis in summer and in moist‐to‐dry habitat utilised by wild reindeer Rangifer tarandus platyrhynchus year‐round. Excluding geese induced vegetation state transitions from heavily grazed, moss‐dominated (only 4 g m−2 of live above‐ground vascular plant biomass) to ungrazed, graminoid‐dominated (60 g m−2 after 4‐year exclusion) and horsetail‐dominated (150 g m−2 after 15‐year exclusion) tundra. This caused large increases in vegetation C and nitrogen (N) pools, dead biomass and moss‐layer depth. Alterations in plant N concentration and CN ratio suggest overall slower plant community nutrient dynamics in the short‐term (4‐year) absence of geese. Long‐term (15‐year) goose removal quadrupled net ecosystem C sequestration (NEE) by increasing ecosystem photosynthesis more than ecosystem respiration (ER). Excluding reindeer for 21 years also produced detectable increases in live above‐ground vascular plant biomass (from 50 to 80 g m−2; without promoting vegetation state shifts), as well as in vegetation C and N pools, dead biomass, moss‐layer depth and ER. Yet, reindeer removal did not alter the chemistry of plants and soil or NEE. Synthesis. Although both herbivores were key drivers of ecosystem structure and function, the control exerted by geese in their main habitat (wet tundra) was much more pronounced than that exerted by reindeer in their main habitat (moist‐to‐dry tundra). Importantly, these herbivore effects are scale dependent, because geese are more spatially concentrated and thereby affect a smaller portion of the tundra landscape compared to reindeer. Our results highlight the substantial heterogeneity in how herbivores shape tundra vegetation and ecosystem processes, with implications for ongoing environmental change.

EDNA Metabarcoding- and Microscopic Analysis for Diet Determination in Waterfowl, a Comparative Study in Vejlerne, Denmark.

Understanding diets and structural food webs are keys to the apprehension of ecological communities, upon which conservation and management biology are based. The understanding of grazing and habitat choice for waterfowl is one of the most important topics for avian ecologists today and can, to some degree, be answered by dietary analysis. Droppings collected from four waterfowl, the Eurasian wigeon (Anas penelope), Greylag goose (Anser anser), pink-footed goose (Anser brachyrhynchus) and Barnacle goose (Branta leucopsis) in Vejlerne (Denmark), were analysed microscopically and through eDNA metabarcoding with the use of next generation sequencing (NGS) to accumulate knowledge about the diet of these waterfowl. In total, 120 dropping samples were microscopically analysed, of which the eDNA metabarcoding analysis was done on 79 samples. The prey items were identified according to the taxonomic level of species, and a qualitative method, frequency of occurrence (FO) and FO calculated as a percentage, was used in order to compare the results from the two methods. As neither of the methods was able to encompass all species discovered when combining the two methods, it was concluded in this study that the two methods can support each other in a dietary analysis of waterfowl, but not replace one another.

Spatiotemporal distribution of Arctic herbivores in spring: Potential for competition?

Biotic interactions are important to the structure and dynamics of food webs and may affect the spatial and temporal distribution of species. In the Arctic, spring snow-cover limits food availability at a critical time for herbivores, potentially leading to resource competition. This study investigates the potential for competition over forage resources during spring in a high-Arctic herbivore community comprising the resident, endemic Svalbard reindeer (Rangifer tarandus platyrhynchus) and Svalbard rock ptarmigan (Lagopus muta hyperborea), and the migratory pink-footed goose (Anser brachyrhynchus) and barnacle goose (Branta leucopsis). First, we investigated herbivore behaviour that could indicate the potential for competition by conducting a field study, and second, we quantified the effects of snow-cover extent, vegetation type and presence of potential herbivore competitors on the spatiotemporal distributions of herbivores using camera-traps in one early and one late snow melt year. Only reindeer and geese appeared with sufficient sample sizes for analysis. The field study revealed that reindeer and geese foraged in the same areas, particularly moss tundra habitats. Although geese were regularly alerted by reindeer, no direct aggressive interactions were observed. The camera-trap study showed that neither of the herbivores significantly affected the spatiotemporal distribution of its potential competitor, but reindeer and goose distribution was instead driven by snow-cover extent and vegetation type. However, the shared space use by these species may lead to different types of interactions, such as facilitation or exploitative competition, which require further assessment, including dietary overlap studies, particularly in the context of climate change-induced shifts in snow melt timing and herbivore abundances.

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

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

Grazing effects of wintering geese on grassland yield: A long‐term study from Northwest Germany

Abstract Escalating conflicts between grassland farming and wintering geese in northern Germany stimulated a long‐term study in order to promote a fair and workable system of compensation of harvest loss. Between 1996 and 2018 standardized experiments were carried out to quantify changes in yield loss and herbage quality. Simultaneously, we weekly monitored the number of geese to relate yield losses to goose numbers and to identify the impact of the different species. Exclosure experiments were established on conventionally managed grasslands. The number of investigated fields differed over the study period (1990s: n = 6, 2000s: n = 14, 2010s: n = 2–18). On each field, we established 12 marked plots (4.5 m2), six with exclosures from early November until the first cut of grass in May and six with access for the geese. In all plots dry biomass and the quality of herbage (contents of energy, crude protein, crude fibre and ash) were determined at first and second harvest. The total goose‐dependent yield losses at first harvest increased from 15% in the year 1996/97 to 50% at the end of the 2010s. The increase corresponds with changes in the maximum numbers and the migratory behaviour of the barnacle goose Branta leucopsis. Yield reductions correlated positively with densities of barnacle geese present in April. In contrast, we found no decline in grassland yields with increasing numbers of greater white‐fronted geese Anser albifrons. In all periods second harvest was not affected. The combined maximum number of both geese which were counted over approximately 23,000 ha of grasslands increased until 2002/03 but levelled off with numbers around 100,000 birds thereafter. While the maximum wintering population of greater white‐fronted geese dropped since 2007/08, the maximum number of barnacle geese increased until mid of 2010s. An increasing proportion of barnacle geese delayed their departure until May. Within each year grazed plots possessed higher energy and crude protein contents than ungrazed controls, suggesting that the geese maximize their potential nutrient intake rate by grazing. Synthesis and applications. The present study reveals a significant increase in goose‐related loss of grassland yields which form the basis for a fair and comprehensible system of compensation payments to affected farmers.

Home range of a long-distance migrant, the Greenland Barnacle Goose Branta leucopsis, throughout the annual cycle

ABSTRACT Capsule Home range area and foraging distance of the Greenland Barnacle Goose Branta leucopsis, a long-distance migrant were calculated and activity patterns were described. Aims To understand the use of space by Barnacle Geese throughout the annual cycle, and to inform effective wildlife management and conservation planning. Methods Tracking data from 29 annual cycles from 18 individual Barnacle Geese were analysed to estimate overall (80–99% utilization distribution; UD) and core (50% UD) home ranges using a Brownian bridge kernel method. Maximum and core foraging distance were then estimated from 80–99% UD and 50% UD, respectively. Finally, daily activity patterns, including the location of roosts and foraging sites, were described, along with variability in home range among seasons and between males and females, and spatial and temporal repeatability. Results Overall home range area was approximately 14 km2 in winter, 9.5 km2 in spring, 7 km2 in the nesting period, 43 km2 in the post-nesting period, and 48 km2 in autumn. However, the core area used by the birds was substantially smaller: mean core home range area was approximately 1.5 km2 in winter, 1 km2 in spring, 2 km2 in the nesting period, 7 km2 in the post-nesting period, and 12 km2 in autumn. Maximum foraging distances were approximately 7 km in winter, 5 km in spring, 3.5 km in the nesting period, 15.5 km in the post-nesting period, and 32.5 km in autumn. Core foraging distances were approximately 5.5 km in winter, 3 km in spring, 1 km in the nesting period, 8.5 km in the post-nesting period, and 19.5 km in autumn. Conclusion Although our study focuses on the movements of Barnacle Geese, such data can be used to inform a range of pure and applied ornithological issues, including resource partitioning, human-wildlife conflicts, and the spread of zoonotic disease.

Monitoring Dropping Densities with Unmanned Aerial Vehicles (UAV): An Effective Tool to Assess Distribution Patterns in Field Utilization by Foraging Geese

Counting of droppings is often, with great effect, used as an indirect method to monitor the appearance and usage of an area by a population covering longer time spans. However, manual detecting and counting of droppings can be time-consuming and tedious, and with a risk of resulting in course estimations. In this context, we studied the use of imaging from unmanned aerial vehicles (UAVs) as a novel and enhanced tool to estimate the dropping densities and distributions of field foraging Arctic migratory geese, such as pink-footed goose Anser brachyrhynchus and barnacle goose Branta leucopsis. Aided by analysis in geographical information systems (GIS), we sought to detect and use fine-scale changes in the within-field dropping densities to evaluate avoidance distance to selected landscape elements. Data in the form of aerial photos from farmed grassland and pastures were collected in areas adjacent to Limfjorden, Northern Jutland, Denmark. The UAV proved usable for detecting droppings from field foraging geese, but with the applied UAV technology only at a low flying altitude (≤3 m), which rendered traditional methods for georeferencing inapplicable. A revised protocol for georeferencing of single aerial photos triggered from low altitudes was successfully developed, which was considered suitable for future use. Analyses based on the performed UAV data sampling allowed for an unprecedented fine-scale estimation of distribution patterns of the goose droppings and further for determination of optimal sampling frequencies (≤12 × 12 m spacing between photo samples) for calculation of density patterns, which reflected differences in foraging activity of geese across whole fields. Contagious dispersions in dropping densities were detected in the majority of fields indicating local, within-field displacements of the geese, which were illustrated by interpolated heatmaps. Additionally, avoidance distances were assessed for four landscape elements and detected with consistent results for windbreaks (100 m), roads (175 m) and wind turbines (1100 m) throughout the ten surveyed fields.

Threatened to least concern and after: the Barnacle Goose Branta leucopsis in Latvia

In Latvia, the Barnacle Goose Branta leucopsis was, except for a period in the first half of the 19th century, reported to be rare or relatively rare from the late 18th century to about 2010. The marked change in conservation status from threatened in 1985 to least concern in 2000 was due to better knowledge about the situation at the Russian breeding grounds and had nothing to do with the occurrence in Latvia. Since the first flock ever of at least 100 individuals was observed in April 2007, the number of spring-staging birds has shown a steady increase. In 2021, numbers reached 5000 birds in the Svēte flood-plain staging area and more than 10 000 in the country as a whole. Numbers were lower in autumn. There are no recoveries or re-sightings of marked individuals indicating the origin of the staging birds. The increase in numbers in Latvia coincided with a marked decline in importance of the islands in the Baltic Sea for breeding and spring-staging Barnacle Geese.

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.

Barnacle goose Branta leucopsis derogation shooting effort in relation to abundance and vulnerable crops

The population of barnacle geese wintering in Denmark has shown a steep increase during the last decades, prompting a parallel escalation of agricultural conflicts. In Denmark, economic compensation to farmers suffering goose damage to crops is not practiced, but despite that the barnacle goose is fully protected, landowners can obtain a permit to undertake so-called derogation shooting (lethal scaring) to reduce local damage to agricultural crops where other means of scaring have been insufficient. Here, we describe the development in numbers and derogation efforts of barnacle geese in Denmark in the period 2010/11 – 2018/19. We demonstrate that differences in the number of issued derogation permits across the country is primarily explained by differences in barnacle goose abundance, and secondarily, by prevalence of vulnerable crops and differences in crop productivity. Hence, derogation efforts are highest in areas with many geese, high proportions of crops vulnerable to goose grazing and high crop yields. Our analysis indicates that the level of conflict, and probably the economic impact of affected farmers, is proportional to the abundance of geese present locally. While the increasing derogation shooting may be a temporary solution to individual farmers, current unorganised practice might only redistribute geese locally and increase energy demands of the affected birds. Currently, there is a lack of alternative and undisturbed accommodation areas in the Danish agricultural landscape for the displacement of geese to achieve a satisfactory effect of derogation shooting.

Use of foster parents in species conservation may cause conflicting objectives: hybridization between Lesser White-fronted Goose Anser erythropus and Barnacle Goose Branta leucopsis

Following the use of Barnacle Geese Branta leucopsis as foster parents in a conservation program for the endangered Lesser White-fronted Goose Anser erythropus in Sweden 1981–1999, mixed breeding pairs of the two species were established in the wild. We find indications that this was related to shared moulting habits of the two species in the Bothnian Sea during late 1990s. Starting in 2003, five mixed pairs produced at least 49 free-flying hybrid offspring until 2013, when the last breeding was confirmed. Reported numbers of hybrids did not increase in parallel to the production of young hybrids over time. After 2013, the number of hybrids started to decrease in Sweden and the Netherlands. Lower numbers of hybrids than expected can partly be explained by management actions taken, but may also be associated with low survival due to genetic outbreeding. Mixed pairs and their offspring entirely adopted the migratory habits of Barnacle Geese, overlapping very little with sites used by Lesser White-fronted Geese. We find no evidence that the hybrids ever posed a serious threat to Lesser White-fronted Geese breeding in Fennoscandia.

Springtime grazing by Arctic-breeding geese reduces first- and second-harvest yields on sub-Arctic agricultural grasslands

Large population increases of Arctic-breeding waterfowls over recent decades have intensified the conflict with agricultural interests in both Eurasia and North America. In the spring-staging region Vesterålen in sub-Arctic Norway, sheep, dairy and meat farmers have reported reduced agricultural grassland yields due to pink-footed geese Anser brachyrhynchus and barnacle geese Branta leucopsis that rest and forage in the region for 3–4 weeks in spring on their way to their breeding grounds on Svalbard. Here, we report from an experimental exclosure design where goose access to plots at three grassland fields in Vesterålen was prevented. The experiment was conducted over 3 years between 2012 and 2014. Goose abundance varied greatly between fields and years as a function of variable spring weather and forage quantity, facilitating evaluation of longer-term impacts under contrasting grazing intensities. First and second harvest yields across fields and years were 20% and 19% higher in exclosures than in plots open for grazing, while total yields (sum of first and second harvests) were on average 27% higher. Within-year effects on harvest yields varied substantially, primarily due to highly contrasting sward development during the spring-staging periods. Cool weather (2012) led to slow sward development and little or no effects on harvest yields, warmer weather (2013) resulted in generally large effects, while variable weather (2014) led to treatment effects varying across fields, with one field experiencing 61% higher yields in exclosures while there were no significant impacts on first-harvest yields at the two other fields. Goose grazing did not increase dry weight-based proportions of weeds. Overall, the farmers' reports on yield-loss due to goose grazing were confirmed, although impacts varied substantially between years. A novel finding is that second-harvest yields were also reduced. For the most affected farmers, it is unlikely that the current subsidy scheme is sufficient to cover all the their losses.

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

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

State dependence explains individual variation in nest defence behaviour in a long-lived bird.

Parental care, such as nest or offspring defence, is crucial for offspring survival in many species. Yet, despite its obvious fitness benefits, the level of defence can consistently vary between individuals of the same species. One prominent adaptive explanation for consistent individual differences in behaviours involves state dependency: relatively stable differences in individual state should lead to the emergence of repeatable behavioural variation whereas changes in state should lead to a readjustment of behaviour. Therefore, empirical testing of adaptive state dependence requires longitudinal data where behaviour and state of individuals of the same population are repeatedly measured.Here, we test if variation in states predicts nest defence behaviour (a ‘risky’ behaviour) in a long‐lived species, the barnacle goose Branta leucopsis. Adaptive models have predicted that an individual's residual reproductive value or ‘asset’ is an important state variable underlying variation in risk‐taking behaviour. Hence, we investigate how nest defence varies as a function of time of the season and individual age, two state variables that can vary between and within individuals and determine asset.Repeated measures of nest defence towards a human intruder (flight initiation distance or FID) of females of known age were collected during 15 breeding seasons. Increasing values of FID represent increasing shyness.We found that females strongly and consistently differed in FID within‐ and between‐years. As predicted by theory, females adjusted their behaviour to state by decreasing their FID with season and age. Decomposing these population patterns into within‐ and between‐individual effects showed that the state‐dependent change in FID was driven by individual plasticity in FID and that bolder females were more plastic than shyer females.This study shows that nest defence behaviour differs consistently among individuals and is adjusted to individual state in a direction predicted by adaptive personality theory.

About breeding of Arctic Jaeger (Stercorarius parasiticus) and Barnacle Goose (Branta leucopsis) in the Kandalaksha Bay of the White Sea

About breeding of Arctic Jaeger (Stercorarius parasiticus) and Barnacle Goose (Branta leucopsis) in the Kandalaksha Bay of the White Sea