Náttúrufræðingurinn - 1955, Blaðsíða 43

ÍSLENZKIR FUGLAR XI
35
number of fulmars in most of the gull colonies and/or to the havoc made in the
colonies by an increasing fox population. I will not deny positively that these fac-
tors may have affected or are affecting the status of the glaucous gull. But never-
theless I think it much more likely that the main reason for the decrease is the
climatic improvement and the simultaneous increase of the great black-back.
Finally it should be mentioned that, since the beginning of natural history ob-
servations in Iceland, the glaucous gull is not known to have established new breed-
ing colonies or to have extended its range in any part of Iceland. In this respect it
contrasts sharply with the great black-back which is steadily increasing and extend-
ing its range. On the other hand, reliablc information is available about several
glaucous gull colonies which have become extinct in recent times. The small colony
on Krisuvikurberg on the south side of the Reykjanes peninsula might be taken as
an example. In 1905 about 20 pairs were found breeding in this place. These have
now disappeared and have been replaced by herring gulls (Larus argentatus) which
are occupying the same sites. The same change seems to be taking place in Langa-
nes where, in 1949, I found only one glaucous gull still breeding among herring
gulls and great black-backs. As the herring gull has also colonized the Westmann
Islands and has recently started to nest at Reykjanes it may be expected that the
glaucous gull will soon become extinct at these places. The herring gull is one of
the three gull species which have started to nest in Iceland during the present
period of climatic improvement. If it continues to extend its range in Iceland, and
particularly if it should reach the Breidafjördur area, it may, along with the great
black-back, become a serious competitor of the glaucous gull.
Flórunýjungar
Á undanförnum árum hefur Náttúrufræðingurinn komið á fram-
færi athugunum grasafræðinga varðandi nýja fundi plantna. Flestir,
sem um þetta efni hafa fjallað, hafa tekið þann kost að setja saman
plöntulista, og hafa margir áhugamenn sótt í þá mikinn fróðleik.
Það er þó eigi að ófyrirsynju, að plöntulistar þessir hafa þótt heldur
þurrt efni og hafa ritstjórar Náttúrufræðingsins komizt í talsverðan
vanda af þeim sökum. Eins og ég gat um í athugasemd í siðasta
hefti hefur það nú orðið að samkomulagi, að Náttúrugripasafnið taki
alla slika lista í sína vörzlu, þar sem áhugamenn geta haft greiðan
aðgang að þeim. Hins vegar er tímaritinu ljúft að birta allar mark-
verðar nýjungar í þessu efni og munu þær framvegis hirtast undir
heitinu flórunýjungar.