Caribou are found throughout the Holarctic from the treeless landscapes of Ellesmere Island, south to the closed canopies of the boreal forest of Ontario, west to the plateaus and mountains of British Columbia, and east to the maritime heath barrens of Newfoundland. The most common census procedure at this time is the aerial-photo-direct-count-extrapolation (APDCE) census. After calving in early July, many of the migratory barren-ground herds gather in huge post-calving aggregations. Aerial photographs are taken of these herds and animals are counted from enlargements made from large black and white negatives. Surveys of calving grounds are preferrable to winter counts because of the limited extent of the calving locales vs. the ranges occupied in winter; again there is no concealing tree cover on upland calving sites compared to the winter ranges. A compromise approach of transect versus random block counting is to use the transect method initially to plot the distribution and density strata.