The waterfowl genus Anser includes all grey geese and sometimes the white geese. It belongs to the true geese and swan subfamily (Anserinae). The genus has a Holarctic distribution, with at least one species breeding in any open, wet habitats in the subarctic and cool temperate regions of the Northern Hemisphere in summer. Some also breed further south, reaching into warm temperate regions. They mostly migrate south in winter, typically to regions in the temperate zone. Numerous fossil species have been allocated to this genus. As the true geese are near-impossible to assign osteologically to genus, this must be viewed with caution. It can be assumed with limited certainty that European fossils from known inland sites belong into Anser. As species related to the Canada Goose have been described from the Late Miocene onwards in North America too, sometimes from the same localities as the presumed grey geese, it casts serious doubt on the correct generic assignment of the supposed North American fossil geese. The Early Pliocene Branta howardae is one of the cases where doubts have been expressed about its generic assignment.[citation needed] Similarly, Heterochen = Anser pratensis seems to differ profoundly from other species of Anser and might be placed into a different genus; alternatively, it might have been a unique example of a grey goose adapted for perching in trees.
Physical charateristics
Different from outer geese basically uniform coloration of body and bill, his bill less black marks, sometimes black spots or blotches present on belly.
Juvenile generally less strongly patterned dorsally and overall has more mottled plumage.
Subspecies rubrirostris has pink bill and paler plumage.
Copyright remark: Most sounds derived from xeno-canto
wingspan min.:
149
cm
wingspan max.:
168
cm
size min.:
74
cm
size max.:
84
cm
incubation min.:
27
days
incubation max.:
28
days
fledging min.:
50
days
fledging max.:
28
days
broods:
1
eggs min.:
4
eggs max.:
8
Range
Eurasia : Central, West
Habitat
Generally associated with water in open country, often with fringe vegetation or near grasslands.
Winters in swamps, lakes and coastal lagoons, or on farmland in open country.
Reproduction
Eggs are layed form March-April in loose colonies. Shallow nest of reed stems and grass, lined with down, among reedbeds, on ground or in trees. The Clutch size is 4-6 eggs and incubation lasts 27-28 days. Chicks have brownish olive down yellow below. This Goose reaches sexual maturity in 3 years. Although greylag geese Anser anser establish long-term monogamous pairbonds, some of the existing pairs do split up (divorce) and new pairs are formed during the annual spring mating period.
During the incubation period the gander stays close to the nest, and when the goslings a few days old leave the nest they are cared for by both parents, at this time small family groups may be formed. The gander will aggressively protect goslings and nest and an intruder will be met by hissing and threatening attitudes or may be attacked.
Feeding habits
Various plants: roots, leaves, stems and seeds also fruits, grain, potatoes and sprouting cereals in winter,.
Forages mostly by grazing on dry land, but also on water, where it sometimes upends.
Video Greylag Goose
httpv://www.youtube.com/watch?v=ZSMAdEcJ7AQ
copyright: youtube
Conservation
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be ncreasing, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern. This goose inhabits the temperate and boreal regions of Europe and Asia. The birds visiting the European Union belong more or less to five distinct populations (Scott & Rose). The first population comprises the sedentary birds of north-western Scotland. It has nearly doubled during the last 20 years and is currently amounting to 5250 individuals. The second population is breeding in Iceland and wintering in Scotland, northern England and Ireland. It increased from 25000 in 1950 to 100000 currently. The third population is breeding in Norway, Sweden, Denmark, Western Germany the Netherlands and Belgium, and wintering from the Netherlands to Spain and Morocco. From 30000 at the end of the 1960’s, it increased to 200000 currently. The fourth population is breeding in north-eastern Sweden, Finland, the Baltic States and Central Europe, transiting in Italy and wintering in Tunisia and Algeria. It is estimated at 20000 individuals and seems to be quite stable. The fifth population is breeding in the Black Sea regions and Turkey. It reaches northern Greece, and can be estimated at 25000 individuals. Its trends are not well known, but it is probably declining
Migration
A few populations sedentary but most birds move southwards to winter in traditional sites at lower latitudes; many European birds follow French coast and concentrate in large numbers, up to 80,000 in Dec/Jan, in Donana marshes, SW Spain. Irregular occurrences often depend on extent of icing during particular winter.
Distribution map
Literature
Title Remote sensing as a technique to assess reedbed suitability for nesting Greylag Geese Anser anser.