66 Barnacle Geese on Kolguev Island
©Wildfowl & Wetlands Trust
Wildfowl
(2013) 63: 56–71
moulting groups were always observed in
areas < 2 km from the nearest Peregrine
Falcon nesting territory. Flock sizes
recorded for moulting non-breeders in the
lake areas were significantly smaller than
along the river (
t
357
= 14.7,
P
< 0.001); they
never exceeded 300 moulting birds, and
mostly varied in size between 20–50
individuals (Table 4).
Discussion
The progress colonisation and expansion of
Barnacle Geese on Kolguev Island can be
divided into several stages, each with its own
specific features. The first stage was the
initial appearance of the geese as a breeding
species on the island in the early 1980s;
subsequently the geese have started to play a
more important role within the island
ecosystem. During the early years, from
1980–2005, the first small breeding colonies
appeared and increased along the coast,
mostly on the spits and estuaries of the big
rivers (Ponomareva 1990; Gavrilo 1991).
The Arctic Fox was not particularly
numerous on the island in the mid-1990s
(probably because foxes were commercially
hunted on the island until the early 1990s,
which at least partly suppressed their
population), but it seems likely that the first
small colonies were established in fox-free
areas, as observations suggest that even
nowadays the spits are only rarely visited by
foxes. Some wet parts of the vast and boggy
Peschanka River delta are difficult for foxes
to access, so small Barnacle Goose colonies
also appeared there. The location of the
colonies close to coastal marsh habitats
suitable for brood-rearing provided
potential for population growth; it therefore
was not surprising that several small delta
colonies, mentioned by Morozov &
Syroechkovsky (2004) as separate colonies
in 1994 and 1995, grew and combined so
that by 2001 there was a large single colony
(mentioned by Anufriev 2005) in the
Peschanka River delta. Later, as the fox
population of Kolguev Island increased
markedly, the delta colony was big enough
to survive, despite more intensive fox
Table 4
. Flock sizes recorded for Barnacle Geese moulting near Peregrine Falcon eyries along
the river bluffs (adjacent to Barnacle Goose breeding colonies) and in the lake areas of central
Kolguev Island in 2008 and 2011.
River bluff sites
Lake areas
Minimum flock size
16
2
Maximum flock size
1,935
300
Mean flock size
452
38
(± s.d.)
(519)
(40)
Number of flocks recorded (
n
)
29
358
