Sterna, bind 7 nr 8 (PDF-fil) - Museum Stavanger

etter lettet tre andre måker fra reiret, og dessuten kom det til et par
som hadde vsrt i luften ikkc langt unna. Kråka prgvdc 3 slippe vekk,
men de skrikende måkene nxrmest omringet: den og prgvde å presse den
ned mot vannflaten. Stadig kom det nye måker til, og i alt var det vel
10-1 5 av dem som hissig slo kråka lengre og lengre ned mot vannet
inntil den var helt skjult av måker. Etter kort tid hadde måkene klart
3 få kråka under vann, og ved stadig å fly ned mot den og oppå den
druknet de den i det grunne vannet. I et stort tre ikke langt unna satt
det 1-6 andre kriker, men de provde ikkc 5 komme til unnsetning. De
tok tvert om flukten da spetaklet var på det verste. Der kråka druknet,
var dct så grunt vann at den ikke sank fullstendig.
(Fra bladet vestf fold^, Tgnsberg, 9. juni 1965.)
Hans Chr. Alsvik.
102. FlocRs of term alighting on tbc sea. - In the morning of 12th
June 1965, while cravelling by the Coastal Express hurtigruten^)
through the narrow fjords south of Finnsnes (Co. Troms), wc came
across large numbcrs of tcrns. As far as specific identification was
possiblc, thcy werc all Arctic Terns, Stutra ~iaradisaca. The birds flew
north, low over the water in irregular flocks of 10 to 100 individuals.
The weather was sunny and rather cold, with a moderate northerly
breen.
To my astonishmcnt a complete flock of about 30 birds suddenly
alighted on the water of the fjord, where the birds remaincd passive for
one or two minutes beforc continuing their northward coursc. The same
behaviour was later shown by several other flocks; a few times only part
of a flock settled on the waters, but never I saw individual birds alight.
Within half an hour of observation several hundreds of terns were scen
swimming in this way. Of course it was impossible to ascertain if the
birds really were actively swimrning or merely floating; the last is perhaps
more ro bable. No particular behaviour of any bird was noted,
neither foraging, nor bathing or preening movements wcre observed.
No possible reason for this most unusual behaviour can be advanced.
In the limited literature at my disposal I have not found mention of
similar incidents. Terns are generally extremcly reluctant to alight on
the watcr for more than a fcw seconds. The only exception seems to be
bathing behaviour, in which the birds indulge cspccially frequently on
hot summer days. However, in any case along the Dutch sandy shores,
most tcrns normally bathe quite close to the shore-line, entering the
water by wading rather than by alighting on it from the air. Moreover,
as mentioncd above, no bathing or preening movcments were obscrved
in this case. As the fjords wcre quite narrow, and many of the $resident>