Sterna, bind 11 nr 4 (PDF-fil) - Museum Stavanger

increase of A. flanrmea and C. spinrrs may be the crop of spruce seeds which
\vas good in 1971. In both years Phglloscoplrs trocbibs and Fringilla
montifringilla were the dominating species. Together they constituted
more than 50% of the stationary population. The number of stationary
species in the study area increased from 9 in 1970 to I I in 1971. The
number of specics from the strip surveys in 1971 was 28. The results
from the study area and the stnp surveys were in accordance with cach
other (Tab. 2).
The study areas on marshy ground were extended from 1 1 ha in 1970
to 94 ha in 1971. The total density in the areas was 64 territories/km2
in 1971 (Tab. 3) which was almost the same as in 1970 (Tab. I).
Attlbtis pratensis showcd a slight increase from 1970 to 1971. For the
other common species the populations were of the same size in the two
years. The number of species in the study area was 14 in 1970 and 12 in
197 1. During the stnp mrveys in 197 1 24 species were observed (Tab. 4).
This year the dominance values from the study areas were in fairly good
accordance with those from the strip surveys.
Great parts of the Forradal area consist of hilly marshes with sparsc
pine trces (Fig. 1). In 1971 surveys were carricd out in a 26 ha study
area in this habitat. The total density was 14 tcrritories/km"Tab. 6).
The number of species in the study area was 10, while the number from
the strip surveys was 3 1 (Tab. 7). The dominance values from the strip
surveys and the study area were not so closely in accordance with ewh
other as in the other habitats (Tab. 6).
Author's address:
Universitetet i Trondheim
2001. Institutt, Rosenborg
7000 Trondheim, Norway