Status of the Kangerlussuaq-Sisimiut caribou population (Rangifer tarandus groenlandicus) in 2000, West Greenland. Technical Report No. 42

Caribou herd size, herd structure, and recruitment estimates are important for management decisions. In March 2000 an aerial
survey by helicopter for caribou abundance
and herd structure was completed in Kangerlussuaq – Sisimiut. Flight height was 100
metres, flight speed was ≤ 100 kilometre/
hour and strip width was 500 metres to
either side of the helicopter. In 1998 and
2000, snowmobile ground surveys for herd
structure were also conducted in February-March. Both aerial and ground surveys
gave annual recruitment estimates.

Mean group size was 2.7 caribou from the
aerial herd structure count and averaged
3.1 from the two ground counts. These
group sizes are similar to previous findings
and typical for Greenland caribou populations. Caribou density was 2.76 per km2 in
the high-density stratum and 1.19 per km2
in the low-density stratum. The former
could be considered a threat to vegetation,
and even the latter has previously been considered too high for range recovery. The calf
percentage to the total herd was 26.5%. The
late winter fertility index and annual recruitment estimate was c. 68 calves per 100
female caribou. This high recruitment rate
will promote rapid increase in the population, specifically since there are no predators. The bull to cow ratio was about one
bull to every 1.2 cows, and is not unusual
compared with North American herds. If
natural mortality is between 4 and 7%, then
on the present herd size between 2,000 and
3,600 animals may be expected to die
annually.

This study’s estimate for the pre-calving population size of the Kangerlussuaq-Sisimiut
caribou herd in region North in March 2000
is c. 51,600 caribou ± 11,200 (90% CI). The
recommended harvest quota for region
North was increased to 7,000 caribou for the August-September hunt 2000, and hunters were asked to shoot more females. The
recommendation was increased to 10,000
caribou for the 2001 hunt, with the stipulation that half the quota should be allocated
to females only, if further population
growth was to be halted. Halting population growth cannot be effectively achieved
through hunter harvest unless females
make up a large proportion of the harvest.

The Kangerlussuaq-Sisimiut caribou herd is
presently capable of increasing rapidly in
number. The present estimate for 2000 is
approximately five times the 1996 estimate
and larger than any previous estimate for
this herd. In addition, there is the possibility
that the herd has expanded its range, and
some suggestion of increased natural mortality and animals in poor condition. Increasing the caribou harvest for this region may
avert a possible rapid increase in herd size
and subsequent range damage.