Stochastic events like e.g. several years in a row with unfavorable weather conditions during the breeding season may drive the Fennoscandian population to extinction, and thus there is an urgent need to protect the population more effectively.
Contrary to all other arctic goose species regularly occurring in Europe, the general migration direction of the western Lesser White-fronted Goose (LWfG) populations is south/south-east, and the wintering sites are mainly located in south-eastern Europe and in the Black Sea/Caspian Sea region. In these areas, the control of hunting as well as the conservation of wetlands is less advanced than in Western Europe, and this is one of the most important reasons for the endangered status of the LWfG, while practically all arctic goose populations wintering in western Europe are thriving.
Threat 1: High mortality due to illegal hunting and accidental shooting
High mortality due to high hunting pressure alone is sufficient to explain the decline of the LWfG populations. The breeding success (juvenile production) of the Fennoscandian LWfG population is in general at a level that is normal for arctic goose species, and the high mortality caused by illegal hunting and accidental shooting during the migration and wintering clearly is the most important single threat for the population. This has become evident based on ringing and satellite tracking programmes.
The LWfG resembles very much the White-fronted Goose (A. albifrons) that is an important quarry species in most countries within the range of LWfG. In addition, hunting practices in sites where LWfG overwinter are currently an overwhelming threat to the population because of inadequate wardening.
Spring hunting of adult birds exert particularly harmful effects on the population. A lower mortality rate as a result of better control on hunting, combined with the good breeding success, would lead to an increasing population trend.
The growth rates of the Brent Goose and Barnacle Goose populations wintering in the western Europe are good examples of the effect of the control of hunting of arctic geese.
Threat 2: Disturbance
Human activities like e.g. traffic (including flight traffic), hiking and tourism (including e.g. fishing tourism in the breeding areas and bird watching at some of the staging sites), agriculture, and hunting (even if the geese are not directly shot) scare the geese and force them to move to sub-optimal and less safe areas for feeding and roosting, and is causing also loss of energy (less time for feeding, feeding in a sub-optimal habitat).
When scared by human activities, the LWfG may also have to fly to/via areas where hunting pressure is high. Disturbance occurs at the staging and wintering grounds and it can be either deliberate, i.e. when birds feeding on crops and natural meadows are scared away by farmers, or it can be caused by hunters, birdwatchers and eco-tourists and in general by increased vehicle traffic and human activity around these areas.
Threat 3: Habitat loss and degradation
The feeding conditions along the migration routes and in the wintering areas have deteriorated through the transformation of the natural steppes into cultivated land, and many wetlands (e.g. important roosting sites) have been drained.This development has happened throughout most of the range of the species.
Furthermore natural grasslands, which are the main foraging habitat for LWfG, are deteriorating due to changes in water management practices and changes in grazing pressure resulting in overgrazing or undergrazing.
In fact, abandonment of traditional practices has resulted in several cases in the deterioration of suitable roosting and feeding habitats due to overgrowth of reeds and encroachment of bushes and trees or other forms of tall vegetation. Reduction of winter cereal cultivations further limits available foraging habitats for LWfG in winter.
Loss and deterioration of preferred, original habitats has forced the LWfG to use sub-optimal and less safe areas for feeding and roosting. The energy intake may be lower than in the optimal habitat, and the competition with other species may be higher, and this may lead e.g. to a lower breeding success. In less safe areas the LWfG may also be shot.
Threat 4: Lack of knowledge
The LWfG is a very rare and consequently poorly known species, and there is still lack of basic knowledge e.g. on the migration routes, staging/wintering sites and conservation requirements at these sites. Due to lack of knowledge, the conservation measures cannot always be targeted and planned in the most efficient way.
There are still fundamental gaps to our knowledge of the species stop over sites even along the European flyway. The previous LWfG LIFE project showed that at least half of the wintering population in northern Greece leaves in some years the main wintering site for another, yet unknown, wintering spot for a period of circa one month between mid-January to mid-February. For areas where the flocks of LWfG might occur irregularly or in very small numbers we have inadequate count data.
Additional threats for the Lesser White-fronted Goose population
Increased depredation by the red fox and possibly also disturbance and ecosystem effects by the over-dense reindeer populations are potential threats on the breeding grounds in Fennoscandia. These threats are not, however, directly targeted by the project, because at the moment the only known breeding sites of the Fennoscadian LWfG are situated in Norway, i.e. outside the LIFE project area.
The previous LWfG Life project (in which Norway took part) started culling of red foxes in the main breeding area, and this important conservation measure is being continued by the Norwegian authorities.
An additional threat for the Fennoscandian LWfG is the possible hybridisation with the reintroduced or escaped captive LWfG. As shown by the recent genetic studies of the captive stocks used in the reintroduction programmes, hybridisation with the White-fronted Goose (Anser albifrons) and Greylag Goose (A. anser) has occurred several times during the captive history.
The reintroduced birds of these captive stocks and their offspring form also threat in the sense that the small unpedigreed captive populations might have accumulated deleterious mutations with untested effects in the wild.
When introduced into small wild population, these alleles might become quickly fixed by genetic drift and accelerate the extinction of the wild Fennoscandian population. The LIFE project does not, however, directly target the genetic threat.