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
during May–August 2009. Surveys were
conducted in spring, the calving season,
postcalving, and late summer; no surveys were
conducted during the insect season in July or in
September and October due to weather and
logistical problems. 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
twice in 2009, around the peak of calving (2–4
June) and near the end of calving (8–10 June).
Summary maps of caribou density were
prepared to compare distribution and density in
2009 with long-term averages from regional
calving surveys since 1993. A helicopter was
used to sample age and sex composition on 11
June. Additional aerial surveys of caribou
distribution and abundance were conducted in
mid-May, late June, early August, and late
August in the Colville East survey area
between the Colville River and the western
Kuparuk Oilfield.
