Nature Conservation Research. Заповедная наука 2019. 4(1): 29–36 https://dx.doi.org/10.24189/ncr.2019.003 RESULTS OF AN AERIAL SURVEY OF THE WESTERN POPULATION OF ANSER ERYTHROPUS (ANSERINI) IN AUTUMN MIGRATION IN RUSSIA 2017 Sofia B. Rozenfeld1,2,*, George V. Kirtaev3, Natalya V. Rogova3,**, Mikhail Yu. Soloviev4,*** 1A.N. Severtsov Institute of Ecology and Evolution of RAS, Russia *e-mail: [email protected] 2State Nature Reserve «Gydansky», Russia 3Goose, Swan and Duck Study Group of Northern Eurasia, Russia **e-mail: [email protected] 4Lomonosov Moscow State University, Russia ***e-mail: [email protected] Received: 11.07.2018. Revised: 05.11.2018. Accepted: 13.11.2018. 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 affect- ing 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. Key words: aerial counts, Lesser White-fronted Goose, monitoring, Nenetsky Autonomous Okrug, Yamalo- Nenetsky Autonomous Okrug Introduction Peninsula, northwesternmost Russia); the Western Anser erythropus Linnaeus, 1758 is the small- main population (nesting in northern Russia west est of the geese in the genus Anser. The species of the Taimyr Peninsula); the Asian main popula- is globally threatened, being recognised as Vulner- tion (nesting in the eastern Taimyr Peninsula and able by IUCN – The World Conservation Union wintering in China). The global population of An- (IUCN, 2006). This species ranked by BirdLife In- ser erythropus has rapidly declined since the mid- ternational as ‘SPEC 1’ within Europe, denoting a dle of the 20th century. The official estimate of the European species of global conservation concern dimension of the decline is in the range of 30% to (BirdLife International, 2004). It is listed in An- 49% between 1998 and 2008 (Jones et al., 2008). nex 1 of the European Council Directive of April The current estimate of the Western main popula- 2 1979 on the conservation of wild birds (79/409/ tion size is 30 000 (Fox & Leafloor, 2018) – 34 000 EEC), in Column A of the Action Plan under the (Cuthbert & Aarvak, 2016) individuals. African-Eurasian Migratory Waterbird Agree- Thus, monitoring and the prospection of new ment (AEWA) and in Annex II «Strictly protected areas could be extremely useful for the assessment species» of the Bern Convention. This species is of the current numbers and state of Anser erythro- listed in the Red Data Book of Russia (Vinogra- pus for the future conservation of this species. The dov & Morozov, 2001) as a rare species (category objective of the present work is, using the most ef- 2). Anser erythropus is a long-distance Palearctic fective methods, to estimate the numbers and status migrant, currently breeding discontinuously in the of the Western main population in the key regions sub-arctic zone from northern Fennoscandia to during the autumn migration. These data could be eastern Siberia. Four subpopulations can be rec- used for conservation on an international scale. As ognised, three of which are surviving components hunting is deemed one of the most negative factors of the species’ formerly more extensive breeding for the species, a large-scale survey would allow range. These are the Fennoscandian population for the creation of hunting free zones at the key (breeding in the Nordic countries and the Kola sites revealed. 29 Nature Conservation Research. Заповедная наука 2019. 4(1): 29–36 https://dx.doi.org/10.24189/ncr.2019.003 It is clear that in vast, inaccessible areas, the up. It became necessary to develop new methods monitoring and counts of migratory birds can be of aerial surveys using the experience of North processed only by using aviation. In North Amer- American countries, including those used in the ica, waterfowl are typically surveyed by aerial 1990s (Poyarkov et al., 2000). Based on North surveys. The Migratory Bird Treaty Act (1918) American experience, we used ultra-light air- requires signatory countries to establish hunting craft on floats for the counts. regulations that ensure sustainability of bird pop- The flyway ofAnser erythropus is very large. ulations while affording harvest opportunities for Anser erythropus nesting in the Nenetsky Au- subsistence and sport hunters. Experimental ef- tonomous Okrug (NAO) moves along the Bar- forts at surveying waterfowl were initiated since ents Sea Coast to the east in autumn. Birds can 1930 (Bowman, 2014). To assess status of bird stay for a longer time in some of the bays there. populations the U.S. Fish and Wildlife Service Subsequently, in Russia the total Western main began developing methods for aerial surveys in population flies via the Dvuobye (over the Bay- the mid-1940s. By 1955, a continent-wide wa- daratskaya Bay) to Northern Kazakhstan and fur- terfowl breeding population survey was opera- ther to the wintering areas. Thus, the eastern part tional in North America. Methods for this survey, of the NAO, the Baydaratskaya Bay (I – in Fig. 1) known as the Waterfowl Breeding Population and and the Lower Ob (Dvuobye) (II – in Fig. 1) are Habitat Survey (WBPHS) were formalised in a important territories within the flyway of Anser protocol document written jointly between the erythropus. The entire Western main population U.S. Fish and Wildlife Service and the Canadian migrates via the Dvuobye (Jones et al., 2008). Wildlife Service in 1987 (Platte, 1987). The WB- In Russia total counts are feasible only along PHS survey was the seed for numerous additional the coast of the Barents Sea and Kara Sea and aerial surveys that focus on specific management in Dvuobye. In these regions after the breeding questions and conservation efforts (Baldassarre & season, Anser erythropus gathers in large con- Bolen, 2006; Kerbes et al., 2009). Within harvest centrations and stays for an extended period. management processes, specific population size Ground counts are impossible due to very large benchmarks have been identified that trigger dif- territories and the absence of roads, leaving aer- ferent harvest strategies. Measuring status relative ial surveys as the best option. The use of light to those benchmarks is accomplished with aerial and ultra-light aviation gives the opportunity to surveys (U.S. Fish & Wildlife Service, 2012). make counts of a whole population occurring in In the US Waterfowl Program currently uses the a very large area within a short time frame. light aircrafts on amphibious floats. This airframe We made aerial surveys and identified the is ideal for long-range flights over variable terrain key sites and main threats for Anser erythropus and conditions. Amphibious floats provide a com- within this part of the flyway. bination of safety for operations beyond gliding distance from the shore and the flexibility to oper- Material and Methods ate on water or runways (Aerial Survey Training Autumn surveys were carried out on 12–13 Manual U.S. Fish & Wildlife Service Migratory and 21–22 September 2017 in Dvuobye, on 15– Bird Management, Alaska Region, 2016). 19 September 2017 in the NAO and on 14 and In the Soviet Union large aircrafts, such as 20 September 2017 in the Baydaratskaya Bay. AN-2 or MI-8, were used. Theses types of air- As the Baydaratskaya Bay is a kind of «swirl» crafts significantly limit the possibility of ob- that attracts birds migrating through Dvuobye to servations and bird counts and are very expen- Kazakhstan, we planned the surveys so that we sive. Unfortunately, at present, the methods of could cover the peak of Anser erythropus migra- aerial surveys and monitoring existing in Russia tion. The surveys allowed covering the majority are hopelessly outdated. There are no approved of the migrating Anser erythropus. methods for aerial surveys of migratory birds in The surveys were carried out using a STER- Russia. Monitoring of their populations at the KH-1S ultralight two-seater single-engine hydro- state level is not carried out. This leads to a not plane. This model is perfect for counting water- sustainable use of waterfowl resources and the fowl by a small number of observers (Rozenfeld lack of effectiveness of measures for their con- et al., 2017). The total area of the territory ex- servation. With the development of light and ul- plored was 23 506 km2. The total route length tra light aviation, entirely new prospects opened was 12 608 km (Fig. 1). The survey routes were 30 Nature Conservation Research. Заповедная наука 2019. 4(1): 29–36 https://dx.doi.org/10.24189/ncr.2019.003 plotted to sites with potentially suitable habitats using a Canon 700D camera with 100–400 mm previously chosen, based on topographic maps lens for mapping.