Freitag, 04 Februar 2022 15:44

ANDERSSON, Å & HOLMQVIST, N. (2010)

The Swedish population of Lesser White-fronted Goose Anser erythropus – supplemented or re-introduced?

Ornis Svecia 20: 202-206.

Abstract:

We have investigated historical records of observations of Lesser White-fronted Goose Anser erythropus of the original Fennoscandian population in the area in Sweden where captive-reared goslings of the same species were released during 1981–1999. The release project has ear-lier been regarded as a re-introduction project. The data in this review include reports from many sources and we can  present  earlier  unpublished  observations  from  the area. The large number of observations of birds from the Fennoscandian population proves that the release of gos-lings in the actual area was a supplementation of a small but extant population and not a re-introduction.

andersson-biblio

Freigegeben in A
Freitag, 04 Februar 2022 11:05

OLSSON, V. (1997)

Breeding success, dispersal, and long-term changes in a population of Eagle Owls Bubo bubo in southeastern Sweden 1952–1996.

Ornis Svecica 7(2): 49-60.

Abstract:

In 1950 when the Eagle Owl became legally protected in Sweden, the species was nearly extinct in most parts of the country and survived only with a small population in the southeastern part of the country, along the Baltic Sea coast. This population has been studied in 1952–1996. Recoveries of birds ringed in the study area demonstrated that dispersal was limited; post-fledging dispersal was on average 56.8 km in the first year of life. In birds older than one year the mean distance from the hatching site to the site of recovery was 47.7 km. The mean brood size in successful nests was 1.47 young. However, the mean reproductive success calculated for all occupied territories was only 0.68 young per pair and year. Among all pairs, 43.7% bred successfully and 24.7% failed. Thus, each year 31.6% of the pairs stayed in the territory without breeding. For an extended part of this long term study, reproduction seems to have been just enough to maintain a stable population size in the study area. Only in the years 1986–90, there seemed to be a surplus of young produced in the study population resulting in new breeding pairs, predominantly outside the old study area. From a national project with captive breeding, 2,759 young Eagle Owls have been released in nearly all parts of Sweden. Around 1982, the number of pairs originating from the released birds was in equilibrium with the original "wild" population, and in 1995 the released birds and their descendants were about twice as many. In recent years probably many pairs are of mixed origin, and the mixing of the two populations is likely to increase in the future. In total, there were about 400 territories occupied by Eagle Owls in Sweden in 1996.

olsson-biblio

Freigegeben in O

Commercial moose meat production in Sweden.

Livestock Production Science 10: 507–516. DOI: 10.1016/0301-6226(83)90077-5 .

Abstract:

Moose meat is produced commercially in Sweden by the hunting of wild, free-range animals. Extensive forests, continual rejuvenation of the browse resource, a moderate climate, and the relative absence of natural causes of mortality contribute to the maintenance of a large and productive moose population. Hunting rights are owned by the landowner and both hunting rights and harvested animals are marketed. Exported moose meat is federally inspected and carcasses are processed in federally approved abattoirs. One commercial operation studied in detail in 1979 had fewer than 1% of its processed carcasses condemned. All traumatized tissue was removed from carcasses during processing. Weight loss associated with carcass cooling plus removal of traumatized tissue averaged 10% of fresh carcass weight. The average retail value of boneless moose meat sold on the Swedish market in 1979 was approximately U.S. $10.00 per kg. The annual moose harvest in 1981 totalled 152 000 animals with an estimated total carcass yield of 19.7 million kg. The present level of commercial production is insufficient to meet the demands of foreign or domestic markets. Not all harvested moose are marketed, however, and the commercial sale of moose meat is increasing, a trend that will probably continue if the recent levels of moose harvest are maintained.

hawley-biblio

Freigegeben in H
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