Chapter 3. Materials and methods
- Table of Contents
- 3.1. The species and populations
- 3.2. Molecular methods
- 3.3. Numts, nuclear copies of mitochondrial sequences
- 3.4. Sequence analysis
Brief outlines of the materials and methods will be provided here, more detailed descriptions can be found in the original papers.
3.1. The species and populations
For paper I, all complete, or nearly so, avian mtDNA control region sequences were fetched from the GenBank (Table 1 in I). Altogether, control region sequences from 68 species comprising 25 genera, 13 families and eight orders of avian fauna were used. For the species used for pairwise comparisons, also cytochrome β sequences were fetched, when available.
Altogether seven Anser goose species (Tribe Anserini) were included in paper II. The lesser snow goose (Anser caerulescens caerulescens) and the Ross’ goose (A. rossii) are Nearctic species, and the white-fronted goose (A. albifrons) is almost circumpolar, whereas the lesser white-fronted goose (A. erythropus), the greylag goose (A. anser), the bean goose (A. fabalis) and the pink-footed goose (A. brachyrhynchus) are Palearctic species (Fig. 3). One to three individuals from each species were included in the study. Three of the species, the Ross’, the lesser white-fronted and the pink-footed geese, are considered monotypic. For the snow goose, the nominate race (A. caerulescens caerulescens) and for the bean goose, the tundra bean goose (A. fabalis rossicus) were studied. Two of the total 4-5 races of the white-fronted goose (A. albifrons albifrons, A. albifrons flavirostris) and both races of the greylag goose (A. anser anser, A. anser rubrirostris) were included. Two of the species, the snow goose (numt sequence) and the Ross’ goose (control region and numt sequence) and one of the races, the eastern greylag goose (control region and numt sequence) were represented by captive individuals.
Figure 3. Breeding distributions of a) the lesser white-fronted goose (circles), the white-fronted goose (alb = Anser albifrons albifrons, fro = A. albifrons frontalis), b) the pink-footed goose (bra = Anser brachyrhynchus), the bean goose (fab = A. fabalis fabalis, mid = A. fabalis middendorffii, ros = A. fabalis serrirostris, mid = A. fabalis middendorffii). The connections of the known lesser white-fronted goose breeding areas to the wintering areas in Greece and China and to a staging area in Kazakhstan are indicated by arrows.
In paper III, the population genetic structure of the lesser white-fronted goose was studied. All of the four known breeding areas of the lesser white-fronted goose in the western and central distributional areas were sampled for the study (Fennoscandia, Bolshezemelskaya Tundra, Yamal and Taimyr). Only one of the eastern breeding areas, Indigirka in Yakutia, is presently known. Because it was not possible to obtain samples of lesser white-fronted geese from the eastern breeding areas for the study, their wintering area in East Donting, China, was sampled. Additionally, material was collected from two non-breeding areas, Kazahkstan and Bulgaria. The material used consisted of blood, muscle and feathers collected during the years 1988-1999. To clarify the levels of genetic diversity of the lesser white-fronted goose prior to the population decline, feathers from museum skins from the years 1889-1945 were obtained in Finland and Norway. Only five out of the 20 feathers obtained were successfully analysed (listed in Table 1 in III).
There are tens of wildfowl farms raising captive stocks of the lesser white-fronted goose in Europe. The species has long been a favourite in captivity and the first record of an attempt to propagate the species in confinement is from the London Zoo in the 1850’s (Delacour 1954). The natural origins of the captive stocks are unknown, but as a consequence of frequent exchange of individuals between the stocks, the genetic composition of the stocks is probably very similar. From one of the captive populations of the lesser white-fronted goose in Hailuoto, Finland, 15 out of 28 individuals present in the stock were sampled (IV).