Barnacle Geese on Kolguev Island 67
©Wildfowl & Wetlands Trust
Wildfowl
(2013) 63: 56–71
predation. Thus, whereas in 1994–1995
Morozov and Syroechkovsky (2004)
reported that they only “sometimes have
seen Arctic Foxes in that area”, by 2006 up
to six Arctic Fox dens were recorded inside
the colony, each with 4–7 pups each year
(authors’ pers. obs.). Despite Barnacle
Geese being the main prey of foxes (pers.
obs.), which placed their dens in and around
the colony, overall nesting success for geese
in the delta colony was still > 90%
(Anisimov 2007). The colony therefore not
only survived successfully but continued to
grow.
Neither Syroechkovsky and Morozov
(2004), during their extensive studies of the
central part of the island, nor other authors
(Glazov 1998; Anufriev 2005) who visited
the island in the 1990s, reported cases of
Barnacle Geese nesting in association with
Peregrine Falcons in the centre of the
island, though the falcons themselves were
described as a rather common breeding
species (Morozov & Syroechkovsky 2004).
This strongly suggests that falcon-associated
inland colonies have appeared more
recently, but prior to the start of our work
(presumably between 2000–2005) and
the expansion to central parts of
Kolguev should be considered to represent
a second significant stage in Barnacle
Goose colonisation of the island. This
development also saw non-breeding
Barnacle Geese move from the Peschanka
River delta to congregate in the vicinity of
the new colonies during the second half of
June, prior to the start of moult. The largest
concentrations of moulting non-breeders
were invariably seen adjacent to these inland
colonies of the upper Peschanka River.
A further development has been the use
of new nesting habitat by the geese in the
last two years of the study, when two
colonies were recorded on dry lake beds
disassociated from raptor nests. These
habitats in themselves were not new for the
species, as they are quite typical nesting
habitats in the Peschanka River delta,
though they might be considered as
secondary for the species in general
(Barnacle Geese having started to use them
only in conjunction with the westward
expansion of the breeding range), whereas
their breeding habitats on steep river banks
are more typical primary habitats (common
for the species in the former core breeding
areas on Novaya Zemlya and Vaigach
Island; Syroechkovsky 1995). Prior to 2011,
we never observed Barnacle Geese nesting
in these habitats in the central parts of the
islands, as in 2006–2008 all inland colonies
were small and strongly associated with
falcon nests for protection. Cases of
skipped breeding, or breeding but with low
hatching success in the cases when falcons
have nested in a particular season, may serve
as additional evidence that during the early
stages of colony (and thus population)
development Barnacle Geese may breed
most successfully in areas inaccessible to
terrestrial predators (such as bluffs, sandy
spits or islands, or under the protection of
breeding falcons), until the colony reaches a
size of several thousands nests where the
presence of foxes cannot prevent its further
growth, as is now the case in the Peschanka
River delta. Nesting on peat hummocks,
protruding from the wet moss mats and on
dry flat ground along the rivers and lakes
banks, therefore appear to be secondary
