Fennoscandian Lesser White-Fronted Goose Conservation Project Annual
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The similarity of the Lesser White-fronted Goose (Anser WWF Finland Report No 12 – NOF Rapportserie Report No 1-2000 erythropus) and the White-fronted Goose (Anser albifrons) is one of the main problems in the conservation of the Lesser White-fronted Goose. The identification of these two species is surprisingly difficult. WWF Finland Report No 12 Size alone can not be used to identify the species. The head of the Lesser White-front is smaller and neater, more rounded (sometimes the NOF Rapportserie Report No 1-2000 head appears to be box-shaped) with a relatively bigger eye and steeper forehead than White-fronted Goose. The bill is relatively much shorter than in White-fronted Goose and almost triangular in shape. The neck of Lesser White-front is distinctly shorter and relatively thicker than in Fennoscandian the White-front. In a flock on the ground, a good hint for sorting out a Lesser White-front is the overall darkness of the bird. In addition, Lesser White-fronts normally show a more upright posture than White-fronts. Lesser White-fronted Goose conservation project The wings of the Lesser White-front are relatively somewhat longer, reaching beyond the tail (when fully grown), but careful observation is Annual report 1999 necessary because also White-fronts can sit in a position where the wings reach beyond the tail. Flight identification (see front cover) In flight, the two species are very difficult to separate. The identification is easier if a direct comparison with the other species is possible. Espe- cially single juvenile Lesser White-fronts in a flock of White-fronted Geese Above. The ground colour of head and neck is one of the are extremely difficult to discover and identify. most important and useful features to separate adult Lesser White-fronted Goose from White-fronted Goose. In the Lesser The colouring of the wing of Lesser White-fronted Goose and White- White-front, the whole head and the upper 2/3 of neck is quite uniformly dark brown, distinctly darker than in the White-fronted fronted Goose is very similar. The primary coverts and the base of a few Goose. In the White-fronted Goose, only a narrow zone at the outermost primaries are quite light blue–grey in both species. Both of rear margin of the white blaze is dark brown, contrasting clearly the species has one clearly visible white wing bar, formed by the white with the light brown head and neck. tips of the greater secondary coverts. Fennoscandian Lesser White-fr The short triangular bill of the Lesser White-front is brighter pink in colour than the bill of the White-front, and the white The smaller size of the Lesser White-front alone is not a good cue for blaze reaches further up on crown. Both species show much flight identification, but the shorter neck and bill, and the relatively some- variation in the size of the white blaze; some individuals (es- what narrower wings are flight identification cues that should be paid pecially 2cy birds in spring) have very small white blaze and the shape of the blaze should not be used as an identification attention to. This, combined with the shape of the head and the uniform feature alone. darkness of the head and the upper neck of the Lesser White-fronted Goose are the only valuable features for flight identification. Even if the swollen bright-yellow eye ring of the Lesser White- fronted Goose is prominent at short distances, it is normally not visible beyond 300 metres, but exceptionally the eye-ring Further information on identification: can be seen with a good telescope at a distance of c. 600 Øien, I.J., Tolvanen, P., Aarvak, T. & Markkola, J. 1999: Occurrence and metres. It is also worth noting that c. 20% of White-fronts of identification of Lesser White-fronted Goose. – Alula 5:18–23. the nominate race show a thin dull yellow eye ring. onted Goose conser vation project – Annual report 1999 Edited by Petteri Tolvanen, Ingar Jostein Øien and Kalle Ruokolainen Adult Bean Goose of taiga race Adult White-fronted Goose Adult Lesser White-fronted Goose Anser fabalis fabalis Anser albifrons albifrons Anser erythropus Illustrations © Jari Kostet 1999 Fennoscandian Lesser White-fronted Goose conservation project – Annual report 1999 Tolvanen et al: Introduction he Lesser White-fronted Goose (Anser erythropus, later LWfG) is a globally Introduction endangered species (Tucker & Heath 1994, Tolvanen et al. 1999), and at present the only threatened arctic goose species in the Palearctic region. The current Petteri Tolvanen estimate of the world population in mid-winter is 25,000–30,000 individuals Juha Markkola (Tolvanen et al. 1999), of which normally approximately 20–40% are juveniles Ingar Jostein Øien T(see e.g. Tolvanen et al. 2000, pp. 43–50 in this report; Markkola et al. 2000, pp. 9–15 in Tomas Aarvak this report). Hunting in the wintering grounds, on migration and also in the breeding grounds has proved to be the main threat to the LWfG populations. In addition, also other significant threats like decrease and deterioration of wintering and staging habitats, human disturbance and increased depredation by e.g. Red Fox (Vulpes vulpes) exist locally. Based on ring recoveries and satellite tracking data, it has become clear that the high hunting pressure alone is sufficient to explain the continuous decline of the LWfG populations. Spring hunting of adult birds, which is still very common in most of the LWfG breeding range in Russia in the staging and breeding areas has especially harmful effects on the population. In China, where the LWfG leave the wintering grounds as late as in early April, the winter hunting pressure from poachers using poison is especially harmful to the eastern populations. The LWfG world population can roughly be divided into two parts of equal size between the western and eastern flyway populations (Lorentsen et al. 1999). The western flyway consists of populations that breed in scattered patches in an area stretching from Fennoscandia to Taimyr Peninsula (see e.g. Morozov 2000, pp. 35–38 in this report), and migrate through north-western Kazakstan (see e.g. Tolvanen et al. 2000, pp. 43–50 in this report) to the still mainly unknown wintering areas somewhere in the Caspian Sea – Black Sea region. Approximately 1,100 LWfG were found in Azerbaijan in January–February 1996 (Aarvak et al. 1996), 440 individuals were reported in Turkmenistan in the winter 1998–1999 (see Markkola 2000b, p. 57 in this report), and recent observations indicate that considerable amounts of LWfG could be wintering in the border area between Uzbekistan, Turkmenistan, Afghanistan and Tadjikistan (see Markkola 2000a, p. 57 in this report), and in the Crimea region in Ukraine (Kondratyev et al. 2000, p. 60 in this report). However, the wintering Photo. A pair of Lesser White-fronted Geese at the Valdak Marshes, Norway. © Ingar Jostein Øien, May 1999. 5 Tolvanen et al: Introduction Photo. Aggressive interactions between pairs of Lesser White-fronted Geese are frequent in the spring staging grounds in Fennoscandia, where the behaviour of LWfG has been studied for several years. In the wintering grounds in China conflicts between individuals were not registered at all during the time budget studies at East Dongting Lake in February 1999. © Ingar Jostein Øien, Valdak Marshes, May 1999. grounds of the main part of the western populations remain unknown. A minor part – apparently not more than a few hundreds – of the western flyway birds migrate via Poland, Germany and Hungary (see e.g. Lorentsen et al. 1998, 1999) to Greece and Turkey for wintering. Out of these, less than 100 individuals presently winter in Greece (see e.g. Lampila 1998, Kazantzidis & Nazirides 1999). Approximately half of the highly endangered Fennoscandian breeding population use this flyway. The eastern flyway populations, breeding in central and eastern Siberia, from the Taimyr Peninsula eastwards, migrate to winter mainly in south-eastern China. Contrary to the situation eport 1999 eport for the western populations, the wintering areas of the eastern populations are better known than the breeding areas. Important wintering areas have been revealed during the 1990’s in China, where the East Dongting Lake being clearly the most important place at the present knowledge (see Markkola et al. 2000, pp. 9–15 in this report; Lei Gang 2000, pp. 16-17 in this report). Most of the breeding areas of the eastern populations are poorly known, but gratifyingly, an important breeding area was localised in the Indigirka River area in Yakutia during summer 1999 (Syroechkovski Jr. 2000, pp. 39-40 in this report). As a result of genetic studies on LWfG in recent years (see e.g. Ruokonen & Lumme 1999, Ruokonen 2000, pp. 54–56 in this report), it has become clear that the western and eastern populations of LWfG are also genetically distinct. In addition, the genetic composition vation project – Annual r Annual – project vation of the Fennoscandian population suggests restrictions to the gene flow with other breeding populations. Therefore, it should be conserved as a separate unit. The genetic studies have also revealed, that the captive LWfG population formerly used for reintroduction in Finland Photo. Risto Karvonen toasting for a – and which is still used in Sweden – is a mixture of western and eastern mitochondrial brighter future for the Lesser White-fronted haplotypes, and approximately 25% of the studied captive LWfG carried the mitochondrial Goose in the opening of the Lesser White- DNA of White-fronted Goose (Anser albifrons). Therefore, the Finnish Ministry of the fronted Goose exhibition in the Sami Mu- Environment and the LWfG project of WWF Finland decided to stop reintroduction in Finland seum Siida in Inari, November 1999 © Maija using the current captive stock.