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Current Size: 76%

A Species Whose Population Crashed

DISTRIBUTION AND ANNUAL LIFE CYCLE

The Red-breasted Goose is a long-distance migrant. It breeds in Arctic Russia, primarily on the Taimyr and adjacent peninsulas. It migrates south through Russia to Kazakhstan, and then west through southern Russia to the north and west Black Sea coasts. The majority of the population currently winters in Bulgaria, Romania and Ukraine. The same migration route is followed, in reverse, in spring.

The winter distribution was markedly different in the past: until the late 1960s, much of the population occurred along the western coast of the Caspian Sea, mainly in Azerbaijan, and in Iran and Iraq.

Although most of the species’ range is well known, there are considered to be gaps in knowledge of the precise distribution. These gaps include the extent of the breeding range, the sites used during migration (particularly in spring) and the distribution during winter (particularly during mild condition) when it is thought that significant numbers may occur away from the Black Sea coast.

Breeding:  The species breeds in the Arctic tundra of Russia, between 67°N and 76°N, and between 67°E and 116°E. The majority of the population nests on three peninsulas to the east of the Ural Mountains: the Taimyr, Yamal and Gydan peninsulas. The Taimyr is believed to support approximately 70% of the population. A very small number of birds may nest west of the Ural Mountains. There is evidence of recent expansion both northwards, eg to the Pyasina delta, and eastwards, into Yakutia. It is, however, possible that the expansion may, in part, reflect lack of documentation of sites used in the past.

Migration: The Redb-reasted Goose migration is believed to follow a relatively narrow route. Four main staging areas are known, though each is relatively large, and birds use many individual sites within each of the areas. There may be other, currently unrecorded, staging sites and some ringing recoveries suggest some birds migrate west of the Urals. Knowledge of the migration route, particularly in Siberia, should therefore be considered incomplete.

Autumn migration from the breeding grounds is initially southwards along a relatively narrow corridor, following the River Ob. The first staging area is in the lower reaches of the Ob floodplains, close to the Arctic Circle, in the Yamal-Nenets region. Further south, there is a key staging area on the middle Ob, between Surgut and the River Vakh, in the Khanty-Mansi region, though it is thought likely that birds also use sites along other parts of the Ob valley. The next main staging area is in northern Kazakhstan, around the Tobol-Ishim forest-steppe and the watersheds of the Ubagan, Ulkayak and Irgizin rivers. The key sites here are centred on the Kostanai region of Kazakhstan, but also in the North Kazakhstan region, and in the adjacent Tyumen, Kurgan and Orenburg regions of Russia. Having reached the southern end of the Urals, migration heads west, passing just north of the Caspian Sea to the fourth major staging area of the Kuma-Manych depression, in the Rostov, Stavropol and Kalmykia regions of Russia. Large numbers are found in the Manych valley in mid November, though they possibly arrive earlier than this. The population continues west to winter in the wets coast of Black Sea area.

The birds follow similar migration route in spring migration towards the breeding grounds in Arctic Russia. In recent years there have been the first projects for satelite tracking of Red-breasted Geese and new information on migration route and stop-over sites is revealed. The migration eastwards usually starts towards the end of February and early March, when geese leave the west coast of Black Sea.

Wintering:  The main winter range lies along the Black Sea coast of western Ukraine, Romania and Bulgaria, particularly in the Dobrudzha region spanning northeast Bulgaria and eastern Romania, and in the coastal area between the rivers Danube and Dniester in Ukraine. The population is highly concentrated at a few locations, and over 90% of birds may occur at less than five sites. Although most birds are found in areas close to the Black Sea coast, small numbers have been observed over 100 km inland in recent winters, particularly in Romania.

Distribution varies between and within winters according to the severity of the weather, with birds generally occurring further south and west during more severe conditions. In very harsh weather, small numbers may winter on the Aegean shore of Greece and Turkey, while during mild conditions, significant numbers may remain in the Manych valley and the bay of Syvash for much of the winter.

A few hundred birds continue to winter in Azerbaijan on the western shore of the Caspian Sea (and perhaps inland), and are also regularly recorded on passage in Hungary, particularly at the Hortobàgy. It has been speculated that there are unknown staging or wintering sites elsewhere around the Caspian Sea, in Iran, Iraq, Turkmenistan, or Uzbekistan, or elsewhere in central Asia and the Middle East, but there is no firm evidence for this at present. Individual birds are frequently seen in many countries in Northwest Europe, but these are vagrant birds outside the species’ normal range and some are possibly escapes.


POPULATION

The first large estimate of the Red-breasted Goose population is 60,000 birds, made in 1956, when the population was centred on the Caspian region. Between this initial estimate and 1967, the population was believed to vary between 50,000 and 60,000 individuals. Between 1969 and 1990, the maximum number recorded in the non-breeding areas was 25,907. Whilst a population decline is suspected to have occurred, it is impossible to confirm or quantify since counts clearly underestimated the true totals, partly as a result of a lack of adequate surveys in the newly established wintering areas. The more comprehensive coverage subsequently enables a confident estimate of 90,000 individuals at the end of the 1990s: 88,000 were counted in Kazakhstan in autumn 1996; and 88,425 were recorded during a survey of the main wintering areas in 2000. This is thought to represent an increase in population size since the 1970s.

Temporal changes in the number of Red-breasted Geese are difficult to determine with confidence, as a result of the practical limitations involved in undertaking comprehensive surveys. Although count data from the wintering range are available from several years throughout the mid 1950s to late 1980s, most figures are clearly unrepresentative. Efforts to undertake co-ordinated surveys began in the early 1990s, and continue to the present day, particularly in Bulgaria, Romania and Ukraine during winter. However census efforts in Kazakhstan and Kalmykia region of Russia during autumn migration period have improved and intensified in recent years.

Counted totals declined dramatically after 2000 (eg to just 23,000 in 2001/02). Whilst these, and subsequent counts, provide strong evidence for a large decrease following 2000, it is unlikely that the decline was as severe as the numbers suggest and these dramatic figures may be in part due to surveying effort. In mild winters, some birds remain farther east in the flyway, where surveys are less comprehensive. Large numbers have been recorded at Manych-Gudilo, Russia, during ad hoc surveys in recent winters, and it is suspected that other birds may winter at as yet unknown sites. In subsequent years higher numbers were reported during spring and  autmn migration. Total counts of 40,800 in spring 2008 (primarily as a result of a large count in Kalmykia) and 44,300 the following winter lend further weight to the suggestion that counts in the mid 2000s were incomplete because birds wintered away from the traditionally surveyed sites. Further higher counts were reported in subsequent years on passage in Kazakhstan, but those were not corroborated by winter monitoring serveys. The highest total count from wintering grounds came in January 2013 during IWC count when around 56,000 birds were counted in Bulgaria, Romania and Ukraine. This is believed to be around the current population of the species. However despite the possible poor coverage of the counts in the early 2000 the numbers clearly suggest a decline in the Red-breasted Goose population of magnitude of at least 50-60% taking into account a population figure of 90,000 birds in the late 1990s.

 


THREATS AND CHALLENGES

1. Changes to the agricultural regime in the wintering areas

In the wintering areas, Red-breasted Geese feed primarily on arable crops and agricultural grasslands. In particular, they favour the shoots or early growth of winter wheat and spilt grain. This is currently the main crop regimes around key roost sites in Bulgaria, Romania and Ukraine, but there has been an increase in the extent of other crops, such as biofuels, grapes, vegetables and sunflowers, which are unsuitable for geese. A change in the agricultural regime, from wheat to cotton, and hunting are believed to have been the primary reasons for the shift in winter distribution from the Caspian to the Black Sea. The switch from arable to other crops is likely to increase, driven by predicted climate change and consequent changes in agricultural policy, and by the financial rewards from ‘cash crops’, particularly in Bulgaria and Romania following their accession to the EU. Crop damage concerns by farmers also causes tension in wintering areas.

2. Abandonment of grazing in staging/wintering areas

Manych-Gudilo, southwest Russia, is a major staging area, and perhaps acts as a bottle-neck for the majority of the population in autumn and spring. A significant number of birds also winter at the site in mild weather. Red-breasted Geese have traditionally favoured semi-natural and agricultural grasslands for feeding but grazing by livestock in the area has largely been abandoned in recent years, primarily because it is not commercially viable. Consequently, the pasture has become too long and is unsuitable for the geese. The reduced feeding opportunity may be particularly serious during migration, and could have a significant effect on the birds’ fitness upon reaching the breeding grounds.

3. Wind farms in the wintering area

The open landscapes around the Black Sea favoured by Red-breasted Geese during winter have a high wind resource, with a substantial potential for wind farm development. Wind farms affect birds mainly through collision with turbines and disturbance displacement, resulting in increased direct mortality and preventing access to feeding areas. Whilst some species habituate to the turbines, and may even feed among them, it may take several years for this change in behaviour to occur. There are some preliminary indications for displacement impact of windfarms in Dobrudzha, suggested by redistribution of foraging flocks in the region following the boom of windfarm development both in Romanian and Bulgarian part of Dobrudzha with over the past decade.

4. Oil and gas infrastructure expansion in the breeding grounds

The breeding grounds of Red-breasted Geese have, until recently, been little-used by humans. The increase in oil and gas operations in the region has, however, seen a significant expansion into previously remote areas and an increase in infrastructure that also allows access by others not directly involved with the energy industry. This has resulted in disturbance of breeding birds by oil and gas operations, and by the increased number of people in the region, through recreation and other activities. Operations may also result in direct habitat loss to a small degree, if infrastructure is inappropriately sited in areas particularly favoured for nesting. Further expansion of operations in the region is anticipated, particularly as the predicted warming of the climate will allow easier access and a more hospitable working environment in more remote areas.

5. Rodenticides

Farmers in the wintering areas of Red-breasted Geese use a variety of pesticides. The use of rodenticides in particular has caused poisoning events in geese, with die-offs seen in Bulgaria, Romania and Ukraine. Though stricter rules are applied now because of EU membership of the first two countries, there are still cases of inappropriate use of rodenticides, which remains a concern for its high potential damage.

6. Hunting

Hunting is a key threat to Red-breasted Geese throughout the flyway. It results in direct mortality, from both accidental and deliberate shooting, while disturbance from hunting activities, regardless of the species targeted, can result in reduced survival. As a long-lived slow-breeding species, the population is sensitive to changes in adult mortality more than in fecundity. Whilst no specific studies have been undertaken for Red-breasted Geese, data from other geese species strongly suggest that anthropogenic mortality (such as hunting and collision) is primarily additive. Thus, it is not compensated for by a density-dependent reduction in natural mortality, and has a direct negative effect on the population trend.

Hunting may also cause high levels of disturbance, even when the intended target is legal quarry species. In particular, as well as shooting birds as they fly to or from roost sites, hunters pursue flocks of geese feeding in fields (which are mostly not within protected areas), causing considerable disruption and loss of feeding time, and which may be critical, for example, during periods of severe weather or prior to migration. The long hunting season in some countries, for example, extending into late winter, is a particular cause of concern, as this affects the birds’ ability to increase energy reserves prior to migration and breeding.

7. Development in the wintering area

The Black Sea coastal zone favoured by wintering geese is an area of rapid infrastructure development. The Romanian coastal area has long been popular with tourists although the Dobrudzha area of Bulgaria is generally sparsely populated. There has, however, been a significant increase in developments, particularly associated with tourism – such as hotels and golf courses – and a large number of proposals have been submitted for further developments in the last five years. General urban expansion is also anticipated to increase.

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© Nicky Petkov
© Nicky Petkov
© Nicky Petkov