Portal to the Lesser White-fronted Goose

- by the Fennoscandian Lesser White-fronted Goose project

Literature type: Scientific

Journal: Biological Conservation

Volume: 281

DOI: 10.1016/j.biocon.2023.110028

Language: English

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Full reference: Marolla, F., Aarvak, T. Hamel, S., Ims, R.A., Kéry, M., Mellard, J.P., Nater, C.R., Schaub, M., Vougioukalou, M., Yoccoz, N.G. & Øien, I.J. 2023. Life-cycle analysis of an endangered migratory goose to assess the impact of conservation actions on population recovery. Biological Conservation 281. https://www.dx.doi.org/10.1016/j.biocon.2023.110028

Keywords: Goose management, State-space model, Management evaluation, Lesser white-fronted goose, Unmarked individuals, Non-breeding dynamics, migration

Abstract:

Evaluating the effectiveness of conservation actions is challenging for migratory species because a population can be impacted anywhere along its route. Conservation actions for the critically endangered Fennoscandian lesser white-fronted goose population include culling of red foxes in the breeding area and habitat improvements and reduction of illegal hunting in the non-breeding areas. One goal of the predator control strategy is to prevent adult birds from using an autumn migration route through western Asia, where mortality is believed to be higher than on the migration route through eastern Europe. We used 23 years of count data obtained at different staging areas to parameterize a seasonal state-space model describing the full-annual cycle dynamics of this population and evaluate whether the recent population recovery was linked to these conservation efforts. The results did not provide evidence that predator control influenced population recovery, as survival on the European route did not appear higher than on the allegedly riskier Asian route. However, adult survival at staging areas on both routes and at wintering sites may have improved in the last decade, suggesting a positive effect of the other conservation initiatives. These results emphasize the importance of including the non-breeding dynamics in population assessments of migratory species and highlight the challenge of evaluating the efficacy of separate conservation actions when a proper experimental design is unfeasible. Our study, which is a unique case of cross-national, coordinated conservation efforts, exemplifies how to model complex population dynamics to assess the influence of costly conservation initiatives.

Literature type: Report

Language: Norwegian In norwegian with english abstract

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Full reference: Kvalnes, T., Follestad, A., Krange, O. & Tombre, I.M. 2023. Evaluering av norsk handlingsplan for dverggås. [Evaluation of the Norwegian action plan for the Lesser White-fronted Goose.] , NINA Rapport 2349. Norsk institutt for naturforskning.

Keywords: dverggås, national action plan, Norway, priority species, conservation actions

Abstract:

The lesser white-fronted goose (Anser erythropus) is a critically endangered species in Norway. Due to a rapid decline in population size since the 1940s the population is now at very low numbers. In the previous three generations, the population has several times consisted of less than 50 reproducing individuals. In addition, the Norwegian breeding population constitutes almost the entire remaining Fennoscandian population of the species. Because of this situation, the lesser white-fronted goose is classified as a priority species with its own regulations in Norway. BirdLife Norway (formerly the Norwegian Ornithological Association) has since 1985 monitored the species annually in Finnmark, northern Norway. Geese have been individually ringed with neck-bands and leg rings, including GPS-loggers, which have identified migration routes from Norway to their wintering areas in Greece. Commissioned by the Norwegian Environment Agency, NINA has conducted an overall evaluation of the implementation of the Norwegian action plan for the lesser white-fronted goose which was launched in 2009. The aims of this evaluation has been 1) to evaluate the achievements of the management goals, 2) to evaluate whether knowledge from the monitoring is organized and disseminated appropriately for practical use, 3) to evaluate how the financial structures and conservation measures have been organised, and 4) to provide input for further knowledge acquisition and implementation of actions. The evaluation was based on relevant published results, such as reports from BirdLife Norway, scientific articles, and other information developed in the project. Informants from various relevant stakeholder groups and end-users have been interviewed. Additionally, a so-called red to green method was applied to evaluate the need for future knowledge needs and management actions. Stopping the ongoing population decline by 2015 and a long-term increase of the population size to a target of 1000 individuals, were the main objectives of the action plan. The second objective has not yet been achieved. However, the earlier population decline has been stopped and the population have displayed a slight positive growth rate. Thus, that the first objective has been achieved. In our evaluation, the change in population growth rate is considered to be an effect of the overall measures which have been made to preserve the species. A revision of the action plan is recommended. New achievable objectives for population size should be implemented as steps on the way towards a viable population size. The red list criteria can be used to define objectives and aid the choice of measures. To reduce adult mortality and increase the reproductive success, several conservation measures have been implemented. No entry zones have been established at important staging sites, such as Valdakmyra in Porsanger municipality and Rørholmen in Alta municipality. Annual culling of red foxes (Vulpes vulpes) in and around the breeding area have been carried out to reduce egg and gosling predation. Bans on hunting for greylag geese (Anser anser) have been imposed in large parts of Finnmark to prevent accidental harvest of lesser white-fronted geese. Extensive international cooperation with Finland, Russia and other countries has been important. Cooperations have included efforts to monitor, reduce illegal hunting and secure important functional sites along the migration routes and in the wintering sites. The conservation measures are in general met with support from the informants. They express that most people are concerned with the conservation of the lesser white-fronted goose. Staff in nature management and at museums use the knowledge generated by the monitoring and various research projects to a large extent. However, there is a lack of knowledge about the conservation efforts among other users of the areas where staging and breeding sites for the lesser white-fronted goose are found. We also observed a need for more accessible dissemination of the knowledge which is generated. Some of the informants expressed that several stakeholders do not agree with the ban on hunting of greylag geese in local areas. The established boundaries for where the hunting ban should apply are especially considered problematic. Several stake-holders also claimed that hunter skills are underrated when the underlying assumption for this ban is that it is difficult for hunters to distinguish lesser white-fronted geese from greylag geese during the hunt. This evaluation recommends that also farmers and hunters are included in the dialogue involved in the management of the lesser white-fronted goose. Enhancing communication will facilitate discussions on potential changes that can be implemented to meet their needs while at the same time mitigating the risk of harming the geese. A discussion on adjusting the boarders of the hunting ban should be part of such a dialogue. Our evaluation indicates that much of the conservation effort carried out has been important and should be prolonged in the years ahead. In addition, some new objectives for the species and conservation measures are suggested. However, the lesser white-fronted goose has a long migration route across many countries. Thus, there is a limit to what can be achieved with unilateral national efforts in Norway. To ensure a high probability of success, it will be extremely important that international efforts are also prioritized. Moreover, the evaluation reveals some knowledge gaps that will be important to fill such that more precise conservation measures can be implemented and the effect of measures, such as red fox removal, can be evaluated in more detail. Internationally, it is particularly important to secure stop-over and wintering sites against illegal hunting, degradation and disturbance. Continued monitoring during wintering, along the migration route and at staging sites in Norway is essential to assess the effects of the conservation measures. Based on information from the interviews, it should also be considered whether a dialogue group should be established. With joint meetings among the representatives from nature management, participants in the conservation measures and other affected stakeholders. A forum is likely to improve communication, allow for exchange of experience and knowledge, and contribute to an increased understanding and acceptance of the conservation measures. Hence, it can contribute to achieving the management goals.

Literature type: General

Journal: Linnut-vuosikirja

Volume: 2021 , Pages: 24-31

Language: Finnish in Finnish with English summary

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Full reference: Tolvanen, P., Karvonen R., Aarvak T, Øien I.J., Kaartinen, R., Lampila P. & Mikander, N. 2022. Kolmenumeroisiin yksilömääriin – kiljuhanhen suojelu 2015–2021. [Conservation of the Lesser White-fronted Goose Anser erythropus in 2015-2021.], Linnut-vuosikirja: 2021, 24-31

Keywords: Finland, trend, numbers, conservation, gsm-telemetry, migration routes

Abstract:

The critically endangered Fennoscandian Lesser White-fronted Goose Anser erythropus population is currently estimated to number roughly 100 individuals. Following a dramatic long-term decline to only some 10 breeding pairs in 2007–2008, the population has since slowly been increasing. The spring staging of the population on the Finnish Bothnian Bay coast has been monitored by the WWF Finland Lesser White-fronted Goose conservation project since 1985. In spring 2017, 124 individuals were counted, which was the highest number during the history of the monitoring. The Bothnian Bay coast was historically also an important autumn staging area and since 2020, the geese have again been staging in the area also during autumn migration. Breeding of the species has not been recorded in Finland since 1995, but the likelihood of locating breeding pairs again in Finnish Lapland is considered to be increasing, as the Norwegian breeding population is growing. As a part of the current international Lesser White-fronted Goose EU LIFE project (wwf.fi/lwfg), environmental DNA is being used to map potential breeding sites in Finland.

Literature type: Thesis

Language: English

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Full reference: Markkola, J. 2022. Ecology and conservation of the Lesser White-fronted Goose Anser erythropus. , PhD thesis, Acta Universitatis Ouluensis. A Scientiae Rerum Naturalium 770. Faculty of Science, University of Oulu, Finland.

Keywords: spring arrival, Anser erythropus, Anser fabalis, breeding schedule, habitat, diet selection, meadow management, population genetic structure, Finland

Abstract:

I studied the rare and threatened lesser white-fronted goose (Anser erythropus), abbreviated LWfG in 1989–1996 in sub-arctic Finnish Lapland (I). The studied subpopulation consisted of 2–15 breeding pairs annually. A total of 30 broods were observed with an average of 2.9 goslings per brood. The 1st year survival of tagged 10 geese was low. Satellite locations, recoveries and resightings were received from NW Russia, Kazakhstan and the Azov Sea area. Cold spells had a negative, and the sum of effective temperatures by 5 July a positive influence on reproduction. Habitat selection (II) was studied in the same area. LWfG preferred the vicinity of water, flat close-range landscape, low forest height and intermediate relative altitudes. LWfG aggregated in the vicinity of conspecifics within the preferred habitats. The averaged RSF model assigned observation and random points correctly with 83.4% success. Locations of historical observations of LWfG matched the predicted distribution of breeding sites. (III) Spring migration patterns on the Bothnian Bay coast of LWfG were examined in 1907–1916 and 1949–2014 and the taiga bean goose (Anser fabalis fabalis) in 1975–2014. Arrival of the short-distance migrant A. fabalis advanced more and earlier than the long-distance migrant A. erythropus, 10.9 days since late 1980’s vs. 5.3 days since the beginning of the 2000’s. In the LWfG, the best model for explaining variation in timing included global and local temperatures, in A. fabalis global and local temperatures and winter NAO. Increasing global temperatures seem to explain trends in both. In the spring staging places of the Bothnian Bay almost all dietary items of the LWfG were Monocotyledons, mostly grasses growing in extensive sea-shore meadows (IV). Only Phragmites, Festuca and possibly Triglochin palustris were preferred. Lesser White-fronts preferred extensive natural meadows. Mowing and grazing benefit the restoration of habitats. Genetic structuring of the LWfG was examined in its whole distribution area from Fennoscandia to East Asia (V). A fragment of the control region of mtDNA was sequenced from 110 individuals. 15 mtDNA haplotypes were assigned to two mtDNA lineages. Molecular variance showed significant structuring among populations: the main western in north-western Russia – Central Siberia, the main eastern in East Asia and the Nordic one, which earns a status as an independent management unit.

Literature type: Scientific

Journal: Bird Conservation International

Volume: 33 , Pages: e42, 1–8

DOI: 10.1017/S0959270922000478

Language: English

Full reference: Kruckenberg, H., Moonen S., Kölzsch, A., Liljebäck, N. & Müskens, GJDM. 2022. Migration routes and stepping stones along the western flyway of Lesser White-fronted Geese (Anser erythropus). Bird Conservation International 33: e42, 1–8 https://www.dx.doi.org/10.1017/S0959270922000478

Keywords: reintroduction, Sweden, migration routes, tracking, Brownian bridge, dBBMM,

Abstract:

In 2015 and 2016 four Lesser White-fronted Geese (Anser erythropus), a globally threatened species, were caught and tagged during spring migration representing nearly 10% of the entire Swedish breeding population at the time. Two of the birds were followed over more than one season. Tracking data revealed an unexpected wide network of migration corridors and staging sites. Autumn and spring migration differed by stepping-stone sites and migration speed. So far unknown key stopover sites were discovered in Denmark, northern Germany, and Sweden. By using dynamic Brownian bridge movement models, the potential areas that Lesser Whitefronted Geese used during migration are described and conservation implications spotlighted. This study provides another important piece of the puzzle describing the migration of Lesser White-fronted Geese in Western Europe.

Literature type: Scientific

Journal: The Journal of applied ecology

Volume: 59 , Pages: 1911–1924

DOI: 10.1111/1365-2664.14198

Language: English

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Full reference: Jones, I.L., Timoshenko, A., Zuban, I., Zhadan, K., Cusack, J.J., Duthie, A.B., Hodgson, I.D., Minderman, J., Pozo, R.A., Whytock, R.C., & Bunnefeld, N. 2022. Achieving international biodiversity targets: Learning from local norms, values and actions regarding migratory waterfowl management in Kazakhstan. The Journal of applied ecology 59: 1911–1924 https://www.dx.doi.org/10.1111/1365-2664.14198

Keywords: biodiversity targets, conservation conflict, ecological modelling, hunting, migratory species, policy‐making; socio‐ecological surveys, Kazakhstan

Abstract:

1) Migratory species are protected under international legislation; their seasonal movements across international borders may therefore present opportunities for understanding how global conservation policies translate to local-level actions across different socio-ecological contexts. Moreover, local-level management of migratory species can reveal how culture and governance affects progress towards achieving global targets. Here, we investigate potential misalignment in the two-way relationship between global-level conservation policies (i.e. hunting bans and quotas) and local-level norms, values and actions (i.e. legal and illegal hunting) in the context of waterfowl hunting in northern Kazakhstan as a case-study. 2) Northern Kazakhstan is globally important for waterfowl and a key staging area for arctic-breeding species. Hunting is managed through licences, quotas and seasonal bans under UN-AEWA intergovernmental agreements. To better understand the local socio-ecological context of waterfowl hunting, we take a mixed-methods approach using socio-ecological surveys, informal discussions and population modelling of a focal migratory goose species to: (a) investigate motivations for hunting in relation to socio-economic factors; (b) assess knowledge of species' protection status; and (c) predict the population size of Lesser White-fronted Geese (LWfG; Anser erythropus; IUCN Vulnerable) under different scenarios of survival rates and hunting offtake, to understand how goose population demographics interact with the local socio-ecological context. 3) Model results showed no evidence that waterfowl hunting is motivated by financial gain; social and cultural importance were stronger factors. The majority of hunters are knowledgeable about species' protection status; however, 11% did not know LWfG are protected, highlighting a key area for increased stakeholder engagement.Simulations of LWfG population growth over a 20-year period showed LWfG are highly vulnerable to hunting pressure even when survival rates are high. This potential impact of hunting highlights the need for effective regulation along the entire flyway; our survey results show that hunters were generally compliant with newly introduced hunting regulations, showing that effective regulation is possible on a local level. Synthesis and applications. Here, we investigate how global conservation policy and local norms interact to affect the management of a threatened migratory species, which is particularly important for the protection and sustainable management of wildlife that crosses international borders where local contexts may differ. Our study highlights that to be effective and sustainable in the long-term, global conservation policies must fully integrate local socio-economic, cultural, governance and environmental contexts, to ensure interventions are equitable across entire species' ranges. This approach is relevant and adaptable for different contexts involving the conservation of wide-ranging and migratory species, including the 255 migratory waterfowl covered by UN-AEWA (United Nations Agreement on the Conservation of African-Eurasian Migratory Waterbirds).

Literature type: Scientific

Journal: Land

Volume: 11 , Pages: 1946

DOI: 10.3390/land11111946

Language: English

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Full reference: Fan, R., Lei, J., Wu, E., Lu, C., Jia, Y., Zeng, Q. & Lei, G. 2022. Species distribution modelling of the breeding site distribution gaps of Lesser White-fronted Goose in Siberia under climate change. Land 11: 1946 https://www.dx.doi.org/10.3390/land11111946

Keywords: climate change, breeding sites, conservation gaps, species habitat conservation, Siberia, Russia

Abstract:

Climate change has become an important cause of the loss of bird habitat and changes in bird migration and reproduction. The lesser white-fronted goose (Anser erythropus) has a wide range of migratory habits and is listed as vulnerable on the IUCN (International Union for Conservation of Nature) Red List. In this study, the distribution of suitable breeding grounds for the lesser white-fronted goose was assessed in Siberia, Russia, using a combination of satellite tracking and climate change data. The characteristics of the distribution of suitable breeding sites under different climate scenarios in the future were predicted using the Maxent model, and protection gaps were assessed. The analysis showed that under the background of future climate change, temperature and precipitation will be the main climatic factors affecting the distribution of breeding grounds, and the area associated with suitable breeding habitats will present a decreasing trend. Areas listed as an optimal habitat only accounted for 3.22% of the protected distribution; however, 1,029,386.341 km2 of optimal habitat was observed outside the protected area. Obtaining species distribution data is important for developing habitat protection in remote areas. The results presented here can provide a basis for developing species-specific habitat management strategies and indicate that additional attention should be focused on protecting open spaces.

Literature type: Scientific

Journal: Ornis svecica

Volume: 31 , Pages: 125–138

DOI: 10.34080/OS.V31.22430

Language: English

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Full reference: Liljebäck, N., Koffijberg, K., Kowallik, C., Månsson, J. & Andersson, Å. 2021. Use of foster parents in species conservation may cause conflicting objectives: Hybridization between Lesser White-fronted Goose Anser erythropus and Barnacle Goose Branta leucopsis. Ornis svecica 31: 125–138 https://www.dx.doi.org/10.34080/OS.V31.22430

Keywords: reintroduction, foster parents, Sweden, hybridization

Abstract:

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.

Literature type: Scientific

Journal: Bulletin of Nizhnevartovsk State University

Volume: 2020(1) , Pages: 98–103.

DOI: 10.36906/2311-4444/20-1/15

Language: Russian (In Russian with English summary)

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Full reference: Emtsev, A. A. & Porgunyov, A. V. 2020. Additional information about the lesser white-fronted goose migration stops in the Surgut district of the Khanty-Mansiysk autonomous okrug — Ugra and the problem of species conservation. Bulletin of Nizhnevartovsk State University 2020(1): 98–103. https://www.dx.doi.org/10.36906/2311-4444/20-1/15

Keywords: migration, hunting, conservation, central part of Western Siberia

Abstract:

The analysis of the photographs sent by the hunters from Sytomino village, Khanty-Mansiysk Autonomous Okrug – Ugra, together with the further survey detected the place of migration stops of Lesser White-fronted Geese in the Middle Ob valley. The birds were staying at the small lake 3.5 km east of the village. On September 12, 2011, one wounded individual was found near the lake at the complex raised bog 9.5 km southwest of the city of Lyantor. Several ways can be suggested by us to save flying Lesser Whitefronted Geese and other species of vulnerable animals at the territory of the autonomous okrug. This will include the following measures to take: an obligatory exam for hunters to be able to identify some species of the regional fauna; large penalties for illegal hunting, more active propaganda of respect for nature and educational work and developing hunting culture. The article also covers economic and organizational issues.

Literature type: Thesis

Language: Chinese (Mandarin) (In Chinese with English abstract and legends)

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Full reference: Ao, P. 2020. Migration strategies and conservation of two large-bodied Anatidae species in East Asia. , Master thesis, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. 105 pp.

Keywords: Satellite tracking, Migration strategy, Land use, Conservation status, China, Yangtze River, Dongting Lake, Poyang Lake, Shengjin Lake

Abstract:

The East Asian-Australasian Flyway (EAAF) is the most threatened flyway in the world. China is located in the center of the EAAF where more than one million Anatidae waterbirds winter every year. With the economic development in China, the loss of wetland has resulted in the declining waterfowl diversity and abundance. In order to conserve the waterfowl population and their habitats in China, it is urgent to define the distribution of key species, determine the distribution of key species and obtain the population estimates and historical changes, the location, land use and conservation status of key habitats. Based on satellite tracking, remote sensing data, field survey, ringing resightings, literature review and expert knowledge, we studied the Whooper Swan Cygnus cygnus, a common species, and the Lesser White-fronted Goose Anser erythropus, a global threatened species. The main results are: Satellite tracking, field survey, ringing resightings, literature review and expert knowledge found the East Asian populations of Whooper Swans summered from Yenisei River in the west to Anadyr River in the East, south to the border between China and Mongolia, and wintered in Xinjiang, Gansu, Qinghai, Beijing, middle and lower reaches of Yellow River in China, South Korea and Japan. The Whooper Swans that summered in central and western Mongolia, wintered in China; swans that summered in eastern Mongolia, wintered in China and South Korea; and swans that summered in Far East Russia, wintered in Japan. The East Asian population of Whooper Swans was estimated as 57,700, which increased compared to that in 2011 (42,000-47,000 individuals). Eight key wintering sites were found in Xinjiang, Qinghai, Henan and Shandong in China, six in the coastal and inland wetlands in South Korea and 14 in Hokkaido, Miyagi, and Iwate counties in Japan. Satellite tracking, ringing resightings and remote sensing data identified five wintering areas of Whooper Swans that summered in western Mongolia, namely, Xinjiang (12%), Gansu-Qinghai (16%), Henan-Shanxi-Shaanxi (51%), Beijing (2%), Shandong (19%), from west to east. The population growth may be related to the artificial food of two largest wintering areas (Henan-Shanxi-Shaanxi and Shandong). Tracked swans mainly used water in autumn, winter and summer (82% in autumn, 74% in winter and 62% in summer), and cultivated land (64%) in spring. 47% of the GPS fixes were in protected areas in summer, higher than those in winter (35%), spring (0%) and autumn (26%). The mean migration duration in spring was 21 days (range March 1 - April 15), and in autumn it was 14 days (range October 3 - November 13). At the same time, it is found that the conservation proportion in spring was 0. Therefore, it is suggested to strengthen the conservation of important stopover sites of the Whooper Swan in the bend of the Yellow River. The migration speed in spring was slower than that in autumn, due to more stopover sites and longer stopover duration in spring, which does not support the classic migration theory which claims that spring migration should be faster than autumn migration. Satellite tracking, field survey, literature review and expert knowledge found that the East Asian Lesser White-fronted Geese that summered from the Anabas River in the west to the Anadyr River in the east, and to the Far East Taiga in the south, wintered in the middle and lower Yangtze River in China, South Korea and Japan. The East Asian population of Lesser White-fronted Geese was estimated as 4,200, which declined compared to that in 2015 (16,000 individuals). East Dongting Lake in Hunan Province is the most important wintering site for Lesser White-fronted Geese, followed by Poyang Lake in Jiangxi Province and Caizi Lake in Anhui Province, and one key wintering site in Miyagi County in Japan. Satellite tracking and remote sensing data found that the major wintering sites of the tracked Lesser White-fronted Geese were Dongting Lake (50%), Poyang Lake (24%) and Shengjin Lake (18%) in China, and they summered in the Arctic tundra of Russia and Far East Taiga. The tracked geese mainly used cultivated land (52% in spring and 45% in autumn), tundra in summer (63%) and wetland (66%) in winter. 87% of the GPS fixes were in protected areas in winter, higher than that in spring (37%), autumn (28%) and summer (7%). The breeding area were located in the less populated Arctic tundra, although the proportion in protected area in summer was low. The Lesser White-fronted Goose was more concentrated in nature reserves during the wintering period, thus the conservation proportion in wintering area is high. Dongting Lake is the largest wintering site. However, its hydrological changes resulted in the decrease of food, degradation of habitats, and might have led to the decrease of population. Therefore, it is suggested to restore and maintain of the natural hydrological process of the wintering habitat of geese. At the same time, the conservation proportion in spring and autumn was relatively low, so it is suggested to strengthen the conserve of Northeast Plain in China, the main stopover sites in spring and autumn. The migration speed of Lesser White-fronted Geese in spring was slower than that in autumn, mainly due to the longer stopover duration in spring, which does not support the classic migration theory. Both the Whooper Swan and the Lesser White-fronted Goose are large-bodied Anatidae waterbirds in EAAF. The overall conservation proportion of the Lesser White-fronted Goose is higher than Whooper Swan, but the number decreased, which may be related to its unique requirement of food and habitat. The Lesser White-fronted Goose was affected by the decrease of food resources caused by the hydrological change of the Yangtze River, while the swan was affected by local conservation measures. Therefore, we suggest conservation strategies for these two species that faced different conservation challenge: the key point for the conservation of the Lesser White-fronted Geese is the restoration and maintenance of the natural hydrological process in the wintering area, and that of the Whooper Swan is to conserve and restore the key natural habitat and reduce the dependence of the swan on artificial food.

Number of results: 109