Náttúrufræðingurinn - 1970, Side 28

170
N ÁTT Ú R U F RÆ ÐIN G U R IN N
were left in the eastern interior north of Vatnajökull and the animals had
become extinct in otlier parts of Iceland. It seems that the reindeer population
was always relatively small, and it never attained great economic importance.
Hunting pressure is thought to ltave been low at all times, and indeed the
decline of the population continued despite long periods of total protection.
The distribution of the reindeer was always limited to three areas with re-
latively light snow. The major factor causing the decline of reindeer in Icelancl
is thought to have been difficult snow condilions limiting access to grazing in
winter. Some range deterioration, both as a result of the animals’ own activities
and because of volcanic eruptions, may have interacted with the climatic fac-
tors. It seems unlikely that reindeer can maintain themselves for any length of
time in those parts of Iceland where they are not presently found.
Table 3 and fig. 2 show the results of aerial censuses of reindeer in tlte
last six years. A steady increase in numbers from 1965 to 1969 was associated
with an increasing proportion of calves, after a decline in 1969 to 1970 the
proportion ol calves was also reduced indicating tlrat winter gra/.ing con-
ditions rather than overhunting was causing the decline. Hunting was permitted
in 1968 and 1969 but not in the otlier years.
'l'he average live weight of adult cows is 83 kg and bulls 127 kg.
The bulk of the diet according to rumen samples consisted of woody species
(44.6%) mainly Salix herbacea, Salix callicarpea and Vaccinium uliginosum and
grasses (31,1%) mainly of Festuca and Ágrostis (Table 5 and fig. 4). The pro-
portion of lichens in the diet was only about 4% which is very low even on
summer grazing, as compared witli results from other countries. This is natural,
however, considering tliat the reindeer ranges are poor in lichens. They
were found on 36 out of 112 sampling sites witlr a very low standing crop
per unit area (Table 2).
The mouth santples are unreliable as there were only seven of them.
There was insignificant difference in the dietary coniposition between age
classes, sexes and plant communities grazed, but a great difference w;is found
between the diet of reindeer and sheep (Table 6) and for that reason there is
limited competition between these animals for forage on sunrmer ranges.
It is estimated that in the period May-October the reindeer herd of 1969
which totalled some 2500 adult animals and 700 calves needs about 10 000
hectares of vegetated rangeland with the carrying capacity found in the
reindeer areas.
Vegetation studies have revealed that about ^4 °f the highland ranges in
Iceland are either overgrazed or fully utilized by domestic sheep and horses
whiclr graze the highlands in the summer. Only in East Iceland and some re-
mote parts of Northwest Iceland is there excess forage available.