Restocking of the Lesser White-fronted Goose
To strengthen the small fragments of lesser white-fronted geese in Sweden
The lesser white-fronted goose (Anser erythropus) (LWfG) is a globally threatened species and is presently the most endangered breeding bird in the Nordic countries. It is classified as Vulnerable by IUCN and listed as Critically Endangered in all three Nordic countries. The global population has rapidly declined since the 1950s and it is estimated that there are only around 20,000–33,000 individuals left in the wild. In Fennoscandia the population has undergone a severe historical decline and today it only occurs in restricted breeding sites in the most northern parts. The Norwegian population scarcely exceeds 30 pairs and no breeding has been observed in Finland for several years. In Sweden, the population consists of ca. 100 birds descending partly from reintroduced birds in the 1980s and 1990s. Hunting along its migration routes, especially in Eastern Europe and in the regions along the Black and Caspian seas, is considered to be the main cause of decline.
The LWfG Project was launched in the 1970s by the Swedish Association for Hunting and Wildlife Management, the Swedish Environmental Protection Agency and WWF. Between 1981 and1999 the project released 348 young birds in Swedish Lapland. The captive-bred birds were released together with barnacle geese (Branta leucopsis) that served as foster parents. The LWfG adopted the migration routes of their foster parents to the wintering grounds in the Netherlands. The reintroduced stock thus uses a migration route that excludes countries with high hunting pressures. The method was very successful and resulted in a small population approaching 100 birds in Sweden.
The restocking attempts were temporarily stopped in 2000 due to the discovery of greater white-fronted goose (Anser albifrons) genes in some of the birds in the breeding population. All contaminated geese in the two main breeding facilities, the Swedish Association for Hunting and Wildlife Management station Öster Malma and Nordens Ark, were therefore phased out from the breeding programme. It was decided not to capture or remove the already reintroduced birds since the frequency of A. albifrons alleles in the reintroduced population was relatively low and since they also carried genes from the indigenous population. The restocking attempts were to continue but now using only pure LWfG of known origin.
In 2006 the project restarted using a breeding population founded from LWfG captured as juveniles in the western parts of the Russian tundra. In order not to jeopardise the wild Russian population, not more than two chicks were allowed to be taken from each brood. After a veterinary examination at Moscow Zoo, the goslings are transported to a new breeding facility established at Nordens Ark. To secure the survival of the valuable new founder population, a second backup population will also be established at Öster Malma. The facility in Nordens Ark has room for about 15 breeding pairs as well as unpaired and sub-adult birds.
In 2010 the restocking of captive-bred birds in Lapland was resumed. Only goslings produced from the new wild-caught birds are now used for restocking purposes and the geese are released without foster parents. Instead a new release method is used where captive-bred geese are imprinted on wild counterparts and follow them on their migration routes. The release takes place in mid-July when the captive-bred birds are transferred to the release site in the Swedish mountains. The release site is located in proximity to nesting grounds of wild LWfG. Prior to the release the goslings are kept in small enclosures to acclimatise to their new environment. All birds are individually marked with metal and colour rings for future identification.
Breeding results under the new founders have been encouraging. The first goslings were hatched in 2008 and until 2012, a total of 86 goslings have been bred and reared by their parents. 52 individuals have been used for restocking purposes in the northern parts of Sweden and Norway. The goal is to strengthen the small fragments of LWfG still living in northern Scandinavia and improve the diversity of the wild stock.
The breeding and restocking project is part of the Swedish Action Plan for the conservation of the species, which also includes monitoring, predation control and awareness campaigns.
WAZA Conservation Project 12016 is implemented by Nordens Ark, the Swedish Environmental Protection Agency, County Administrative Board and the Swedish Association for Hunting and Wildlife Management. Nordens Ark's part of the project is funded by the Swedish Environmental Protection Agency, Hasselblad Foundation and Fondation Segré.
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