The focus of this study was the distribution,
abundance, and calf production of Central
Arctic Herd (CAH) caribou between the
Colville and Kuparuk rivers in northern Alaska
from late winter to fall 2010. Surveys were
conducted in late winter (April), the calving
season (early June), postcalving (late June),
late summer (early and mid-August) and fall
(mid-September). No surveys were scheduled
during the insect season in July. Neither of two
surveys scheduled in October could be
conducted because of persistent inclement
weather. Incidental sightings of other species
of large mammals were recorded during aerial
surveys for caribou and other species (mainly
birds).
A fixed-wing airplane was used to survey the
calving distribution and abundance of caribou
once in 2010, near the end of calving (8–9
June). Summary maps of caribou density were
prepared to compare distribution and density in
2010 with long-term averages from regional
calving surveys since 1993. A helicopter was
used to sample age and sex composition on 11
June.