Náttúrufræðingurinn - 1976, Blaðsíða 42

on 23 April on Lake Mývatn, north
Iceland (about 240 km NE o£ Laugar-
vatn). At Mývatn the male smew was
found courting Barrow’s goldeneye fe-
males and engaged in disputes with terri-
torial males until late May. It joined
moulting parties of Barrow’s goldeneyes in
fune and was seen on 25 June 1976 be-
ginning the moult into eclipse. It was last
seen at Mývatn during 22—23 August
in eclipse but apparently able to fly.1)
It is suggested that both smews reached
Iceland by being caught up in flocks
of Bucephala clangula originating in
northern Europe and wintering in soutli
Iceland. Conversely, Bucephala islandica
recorded in northern Fennoscandia and
northern Russia in summer (cf. Bauer
and Glutz von Blotzheim 1969 for con-
tinental records of islandica) probably
stray there from Iceland with clangula
returning from their wintering grounds
in south Iceland.
Extensive censusing in soutli Iceland
in March 1976 indicated that about 250
Barrow’s and about 100 common golden-
eyes wintered there on ice-free lakes and
rivers, i.e. a ratio of about 2.5 Barrow’s
to 1 common goldeneye. Most of the
common goldeneyes were, however con-
centrated on a single lake (Apavatn), and
i£ this is excluded the ratio becomes
about 10:1. Assuming that smews do not
distinguish between the two goldeneye
species and that they move relatively
passively with these species, tlie proba-
bility of their abmigrating to Mývatn witli
islandica from soutli Iceland, rather than
returning to nortli Europe ,should be of
this order. This is borne out by the
evidence presented here, as botlt smews
took this route independently.
1) A male smew (probably the same individual) was seen on Novemberll, 1976
on Ulfljótsvatn. A female was seen on Mývatn on November 14, 1976.
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