Results of an aerial survey of the western population of Anser erythropus (Anserini) in autumn migration in Russia 2017

The global population of Anser erythropus has rapidly declined since the middle of the 20th century. The decline in numbers has been accompanied by the fragmentation of the breeding range and is considered as «continuing affecting all populations, giving rise to fears that the species may go extinct». Overhunting, poaching and habitat loss are considered to be the main threats. The official estimate of the dimension of the decline is in the range of 30% to 49% between 1998 and 2008. Monitoring and the prospection of new areas are needed for the future conservation of this species. The eastern part of the Nenetsky Autonomous Okrug, the Baydaratskaya Bay and the Lower Ob (Dvuobye) are important territories for the Western main population of Anser erythropus on a flyway scale. Moving along the coast to the east, Anser erythropus can stay for a long time on the Barents Sea Coast, from where they fly over the Baydaratskaya Bay to the Dvuobye. We made aerial surveys and identified key sites and the main threats for Anser erythropus on this part of the flyway. According to our data, the numbers of the Western main population of Anser erythropus amount to 48 580 ± 2820 individuals after the breeding season, i.e. higher than the previous estimates made in autumn in Northern Kazakhstan. The key sites of Anser erythropus in this part of the flyway were identified

Estimation of the populations status and habitat conditions of Anseriformes in the State Nature Reserve «Gydansky» (Russia) using ultralight aviation

The Gydan Peninsula is one of the least explored and inaccessible Arctic regions in both the Yamalo-Nenetsky Autonomous Okrug and Russia as a whole. In 2016–2017 we conducted a survey of the Gydansky State Nature Reserve and adjacent areas, counted and assessed the quality of habitats of Anseriformes and their threats. The results of the study and the data volume obtained have proved the effectiveness of using ultralight aviation to study a hard-to-reach and vast area. We elaborated the methodology of aerial surveys and counting, the technique of population abundance extrapolation based on modern statistical methods and the use of Landsat images. According to the data obtained, we created GIS databases on abundance, biotopic distribution, key conservation areas of Anseriformes and threats. On their basis, it will be possible to develop a scheme of long-term monitoring of Anseriformes, and specific recommendations on the protection regime. By preliminary assessing the habitat quality on the selected plots, we found that Anseriformes form main groupings on salt marshes, although their areas on the Gydansky Peninsula are not large. The preliminary study of the feeding spectrum of herbivory Anseriformes (Anser, Branta, Cygnus) showed that on three studied sites, a significant proportion of their diet is occupied by common plant species of salt marshes (Carex subspathacea + Puccinellia phryganodes). Studies of the pastures quality on salt marshes on molting sites and on control sites demonstrated that Anser albifrons and Branta bernicla provoked a decrease in phytomass of dead grass by an average of 5.3 times. This increases the pasture quality and prevents turfness. On the molting sites examined, the phytomass of the main feeding plants was on average 4.6 times less than on the control sites. However, we can not consider it as a negative influence, since the constant pasture grazing stimulates the vegetation growth. Based on data obtained during the preliminary study, we established the impact of Anseriformes on invertebrates. We found that on control sites, the number of spider species was two times higher than on molting sites, and their number was four times higher than on molting sites. There were no significant differences in the Acarini number. The presence of mass concentrations of Aneriformes influences the structure of dominance in the microarthropod communities. We did not establish the influence of the Anseriformes concentrations on the diversity and species composition of Coleoptera and Heteroptera. Although on sites of mass concentration of Anseriformes, the number of Heteroptera predators greatly reduced (in 3–23 times). We showed that Ursus maritimus have became an important factor that influence the Anseriformes abundance, especially colonial species. We distinguished the nine sites which are the most important for Anderiformes. Within these areas, annual monitoring of Anseriformes using ultralight aviation is most relevant. On the distinguished key sites outside the Gydansky State Nature Reserve, it would be advisable to create regional-level complex sanctuaries with complete hunting ban. The presence of people and transport in protected areas will create an increase in the disturbance factor and poaching. It is necessary to strengthen the protection regime and conduct raids to combat poaching both in the Gydansky State Nature Reserve and on distinguished key sites. We propose the use of ultralight aviation as the most effective method for these targets. The results of obtained aerial surveys showed that the highest abundance of Polysticta stelleri, Somateria spectabilis and Clangula huemalis, the maximal concentrations of molting Cygnus bewickii, Anser albifrons, A. fabalis and Branta bernicla were recorded on Neupokoev Island and Vilkitsky Island. In this regard, we assert the necessity to revise the existing boundaries of the Gydansky State Nature Reserve by including into the Protected Area the following sites: Vilkitsky Island together with the Vostochnaya Spit and Shvede Bay, the Neupokoev Island together with the Neupokoeva Spit and water areas adjacent to these islands at a distance of 5 km from the coastline

Two distinct flyways with different population trends of Bewick's Swan Cygnus columbianus bewickii in East Asia

Two of the most fundamental ecological questions about any species relate to where they occur and in what abundance. Here, we combine GPS telemetry data, survey data and expert knowledge for the first time to define two distinct flyways (the East Asian Continental and West Pacific flyways), migration routes and abundance for the Eastern population of Bewick’s Swan Cygnus columbianus bewickii. The Eastern population is the largest flyway population, supporting c. 77% of Bewick’s Swan numbers globally. GPS telemetry data showed that birds breeding in the Russian arctic from the Yamal Peninsula to c. 140°E (including the Lena and Yana Deltas), winter in the middle and lower reaches of the Yangtze River in China (which we label the “East Asian Continental flyway”). Bewick’s Swans breeding from the Indigirka River east to the Koluchin Bay winter in Japan, mostly in Niigata, Yamagata and Ishikawa Prefectures (the “West Pacific flyway”). There was no overlap in migration routes used by tagged individuals from the two flyways. Counts of Bewick’s Swans in the East Asian Continental flyway during the 21st century have shown wide between-year variations, reflecting incomplete coverage in earlier years. Bewick’s Swans in this flyway currently numbers c. 65,000 birds based on extensive wintering survey coverage, compared to c. 81,000 in the early 2000s, based on less complete coverage. Chinese-wintering swans now concentrate mainly (c. 80%) at Poyang Lake in Jiangxi Province and Hubei Lakes (mostly in Longgan Lake), compared to a more widespread distribution both within Poyang and throughout the Auhui Lakes in 2004 and 2005. In contrast, Bewick’s Swans of the West Pacific flyway now numbers c. 40,000, compared to just 542 in 1970. This population has shown no significant overall change since 2004, when it numbered c. 45,000 birds. Small numbers within this population probably also winter in South Korea. These results provide our first basic understanding of the winter distribution of Chinese- and Japanese-wintering Bewick’s Swans in relation to their breeding areas, confirming the need to coordinate future research and monitoring in the two flyways, as well as the need for more information on swans wintering in South Korea