Literature type: Scientific
Journal: Bird Conservation International
Volume: 26 , Pages: 397-417.
DOI: 10.1017/S0959270915000386
Language:
English
Full reference: Jia, Q., Koyama, K., Choi, C.-Y., Kim, H.-J., Cao, L., Liu, G. & Fox, A. 2016. Population estimates and geographical distributions of swans and geese in East Asia based on counts during the non-breeding season. Bird Conservation International 26: 397-417. https://www.dx.doi.org/10.1017/S0959270915000386
Keywords: Population size, survey, South Korea, Japan, China,
Abstract:
For the first time, we estimated the population sizes of two swan species and four goose species from observations during the non-breeding period in East Asia. Based on combined counts from South Korea, Japan and China, we estimated the total abundance of these species as follows: 42,000–47,000 Whooper Swans Cygnus cygnus; 99,000–141,000 Tundra Swans C. columbianus bewickii; 56,000–98,000 Swan Geese Anser cygnoides; 157,000–194,000 Bean Geese A. fabalis; 231,000–283,000 Greater White-fronted Geese A. albifrons; and 14,000–19,000 Lesser White-fronted Geese A. erythropus. While the count data from Korea and Japan provide a good reflection of numbers present, there remain gaps in the coverage in China, which particularly affect the precision of the estimates for Bean, Greater and Lesser White-fronted Geese as well as Tundra Swans. Lack of subspecies distinction of Bean Geese in China until recently also limits our ability to determine the true status of A. f. middendorffii there, but all indications suggest this population numbers around 18,000 individuals and is in need of urgent attention. The small, highly concentrated and declining numbers of Lesser White-fronted Geese give concern for this species, as do the major declines in Greater White-fronted Geese in China (in contrast to numbers in Japan and Korea, considered to be a separate flyway). In the absence of any demographic data, it is impossible to interpret the causes of these changes in abundance. Improved monitoring, including demographic and tracking studies are required to provide the necessary information to retain populations in favourable conservation status.
Literature type: Scientific
Journal: Berkut
Volume: 7 , Pages: 30-31
Language:
English
summary in Ukrainian
Full reference: Soultanov, E., Mosley, P., Paynter, D. & Aarvak, T. 1998. Results of geese and swans counts during wintering in Azerbaijan in 1993 and 1996. Berkut 7: 30-31
Keywords: Azerbaijan, wintering, geese, swans, globally threatened species
Literature type: Scientific
Journal: Syst. Biol.
Volume: 45 , Pages: 415-450.
Language:
English
Full reference: Livezey, B.C. 1996. A phylogenetic analysis of geese and swans (Anseriformes: Anserinae), including selected fossil species. Syst. Biol. 45: 415-450. https://www.dx.doi.org/10.1093/sysbio/45.4.415
Keywords: phyologeni, distribution, fossil, morphology, ecomorphology, comparative analysis, cladistic, geese
Abstract:
A phylogenetic analysis of modern and selected fossil geese and swans was performed using 165 characters of the skeleton, trachea, and natal and definitive integument. Five shortest trees were found (length = 318; consistency index for informative characters = 0.634), which differed only in details of relationships among three species of Branta. Thetrees supported (1) †Cnemiornis as sister group to other taxa analyzed; (2) a sister group relationship between the moa-nalos of Hawaii and other geese and swans; (3) Cereopsis as sister group of Anser, Branta, Coscoroba, and Cygnus (contra Livezey, 1986, Auk 103:737–754); (4) monophyly of Anser, Branta, and †Geochen and confirmation of generic monophyly of each; and (5) Coscoroba as sister group to Cygnus. Selectiveexclusion of fossil taxa from the analysis variably affected inferred relationships and had substantial impacts on computational efficiency. Some nodes were not robust to bootstrapping: (1) nodes relating species groups within Anser, Cygnus, and †Thambetochen and (2) the node uniting Anser, Branta, Coscoroba, and Cygnus relative to Cereopsis. Bremer (decay) indices indicated similar differences in relative support for nodes. Skeletal characters were comparatively important in establishing higher order relationships, whereas integumentary characters were critical for lower order inferences. Constrained analyses revealed that other proposed phylogenetic hypotheses entailed variable penalities in parsimony. The shortest tree(s) was considered with respect to selected ecomorphological attributes (e.g., body mass, sexual size dimorphism, clutch size) and biogeography, and a revised phylogenetic classification of the geese and swans is proposed.
Literature type: Book
Language:
English
Full reference: Madge, S. & Burn, H. 1988. Wildfowl. An identification guide to the ducks, geese and swans of the world. , Chrisopher Helm Ltd., London. Pp.:139-140.
Keywords: status
Literature type: Book
Language:
English
Full reference: Johnsgard, P.A. 1978. Ducks, geese and swans of the world. , University of Nebraska Press, Lincoln.
Keywords: status
Literature type: Proceedings
Language:
English
Full reference: Rakhilin, V. 1972. Migration routes and the character of the passage of swans and geese in the far east. , Pp.172 in: Kumari, E. (ed.). Geese in the USSR. Proceedings of a conference Estonia, May 1970. Tartu, Academy of sciences of the Estonian SSR.
Keywords: migration
Number of results: 6