Goose Colony Research Articles

Breeding range expansion of Barnacle and Brent Geese in the Russian European North

In 1990 a large settlement of Barnacle Geese, Branta leucopsis, was discovered in salt marsh grassland near Shoina (67°50?N. 44°10?E), on the Kanin Peninsula, Russia. The settlement consisted of approximately 350 breeding pairs in 1990 and 400–450 pairs in 1991. Three nests of the Brent Goose (B.b.bernicla) were also found at the edge of the Barnacle Goose colonies. These high Arctic goose species, which traditionally have their breeding grounds in northern Russia, have begun colonising on the Kanin Peninsula only recently, the Barnacle Goose since the early 1980s and the Brent Goose since 1990. Factors contributing to the successful colonisation of these two goose species on the Kanin Peninsula and to the present day expansion of the Barnacle Goose breeding range are discussed.

Breeding range expansion of barnacle and brent geese in the Russian European North

In 1990 a large settlement of Barnacle Geese, Branta leucopsis, was discovered in salt marsh grassland near Shoina (67°50?N. 44°10?E), on the Kanin Peninsula, Russia. The settlement consisted of approximately 350 breeding pairs in 1990 and 400–450 pairs in 1991. Three nests of the Brent Goose (B.b.bernicla) were also found at the edge of the Barnacle Goose colonies. These high Arctic goose species, which traditionally have their breeding grounds in northern Russia, have begun colonising on the Kanin Peninsula only recently, the Barnacle Goose since the early 1980s and the Brent Goose since 1990. Factors contributing to the successful colonisation of these two goose species on the Kanin Peninsula and to the present day expansion of the Barnacle Goose breeding range are discussed.

Destruction of Wetland Habitats by Lesser Snow Geese: A Keystone Species on the West Coast of Hudson Bay

SUMMARY (1) Large numbers of lesser snow geese breed in colonies in coastal brackish and freshwater marshes in the lowlands along the west coast of Hudson Bay. Where colonies are present, the geese determine the structure and species composition of the coastal plant communities. (2) During recent decades, substantial increases in the number of birds have occurred, resulting in the outward spread of the colonies into new areas which are used for nesting, feeding and moulting. (3) Patterns of foraging vary in space and time. In spring at the nesting sites, before the onset of above-ground growth of vegetation, adult geese grub for roots and rhizomes of graminoid plants in relatively dry areas, and in wet habitats they eat the swollen bases of shoots of sedges, particularly Carex aquatilis. In summer, adults and goslings graze intensively on leaves of grasses and sedges over wide areas. Swards dominated by Carex subspathacea are produced in brackish marshes, but the leaves of graminoids of the freshwater sedge meadows are also clipped extensively. (4) Grubbing of vegetation by geese each spring creates bare areas (1-5 mi2) of peat and sediment. The increased numbers of birds have increased the scale of disturbance, with large areas now stripped of vegetation, particularly by the McConnell River. At some sites, erosion of peat has exposed the underlying glacial gravels. There is little likelihood that the vegetation which re-establishes will closely resemble the original. Further expansion of goose colonies in this region may be limited by available food resources.

LIFE HISTORY STUDIES OF THE LESSER SNOW GOOSE (ANSER CAERULESCENS CAERULESCENS). IV. THE SELECTIVE VALUE OF PLUMAGE POLYMORPHISM: NET VIABILITY, THE TIMING OF MATURATION, AND BREEDING PROPENSITY.

Cooch (1961, 1963) suggested that changes in the genotypic composition of snow goose colonies comprising the Hudson Bay-Foxe Basin population could be attributed to selection favoring the blue phenotype. In the preceding paper (Cooke et al., 1985), we examined potential differences in net fecundity between the two phenotypes at La Pérouse Bay in northern Manitoba. No substantial differences in any component of fecundity were detected. In the present paper, we examined potential differences in pre-reproductive and adult viability, age of maturation, and breeding propensity. Again, no differences associated with the plumage polymorphism were detected in any of these life history characteristics. Thus, despite a thorough analysis of the complete life cycle, we were unable to uncover any evidence supporting a selection hypothesis for the persistence and dynamics of this conspicuous polymorphism. An alternate hypothesis based primarily on gene flow and assortative mating appears more plausible.

Lesser Snow Goose Colonies in the Western Canadian Arctic

predicting temporary impacts or mitigating losses when large numbers of moose are displaced by wildfires, hydroelectric development, roads, or fences into areas already occupied by resident moose. Acknowledgments.-We thank R. E. LeResche, J. L. Davis, and P. D. Arneson, who formerly worked at the Kenai Moose Research Center, and D. E. Knight and K. B. Schneider, who reviewed the original manuscript.

Ross' Goose and Lesser Snow Goose colonies in the central Canadian Arctic

A total of 133 700 nesting Ross' Geese and Lesser Snow Geese (Anser rossii and Anser c. caerulescens), in 30 colonies, were photographed in the central Canadian Arctic, Queen Maud Gulf, N.W.T., in June 1976. Estimated species totals were 77 300 Ross' Geese and 56 400 Lesser Snow Geese (of which 15% were blue phase). Species totals were calculated from a photographic census of all Ross' Geese and white phase Snow Geese combined with assumptions based on the estimated proportion of blue phase Snow Geese in each of the 10 largest colonies and the estimated proportion of Ross' Geese in the largest colony. Comparison with a previous visual nesting inventory suggested that from 1967 to 1976 Ross' Geese doubled in number while Lesser Snow Geese increased fivefold. Nesting resources do not appear to be limited.

Gene Flow between Breeding Populations of Lesser Snow Geese

THE measurement of gene flow between natural populations of animals in the field has rarely been achieved in population biology. The nesting colonies of Lesser Snow Geese (Chen c. caerulescens) in the Hudson Bay area provide a favorable situation for such measurements-they are relatively discrete, often separated by hundreds of miles (Fig. 1), and, at many of the colonies, large numbers of geese have been marked with leg bands, facilitating the detection of movement between colonies. The Lesser Snow Goose is dichromatic, comprising blue and white (snow) phases; this dichromatism is controlled by a single gene or tightly linked group of genes (Cooke and Mirsky 1972). In this paper the names Lesser Snow Goose or Snow Goose will be used to denote the species, and blue and white to denote the color phases. The ratios of blue to white phase individuals differ significantly from colony to colony and have changed within colonies in the recent past (Cooch 1963). A westward spread of the blue phase led Cooch to postulate some exchange between colonies. The lack of morphological differentiation between Lesser Snow Geese from different colonies (in contrast to that of Canada Geese (Branta canadensis) nesting in the same region that show significant regional morphological variation (Maclnnes 1966)) is consistent with the considerable gene exchange between different Snow Goose colonies. The two color phases mate assortatively (Cooch and Beardmore 1959). Cooke and Cooch (1968), on the basis of a genetic analysis of the Boas River colony, postulated that individuals select mates according to the color phase of their parents. Mate selection might be modified by the relative availability of each color phase at the time of mate selection. Lemieux and Heyland (1967) and Cooch (1961) showed that white phase birds from the Koukdjuak and Boas River colonies, respectively, tended to have a more westerly fall migration route and wintering range than blue phase birds from the same colonies, although separation was far from absolute. This phenomenon is hereafter referred to as differential phase migration. The migration and wintering distributions of the two colonies shared large areas of overlap, indicating that birds from at least two colonies mixed at this time. If pair formation occurred during this period, interchange between colonies would result unless the geese possessed a special means of recognizing birds from their own colony or unless birds from a single colony maintained exclusive flocks. The purpose of this paper is to determine the amount of gene flow