The Porcupine caribou herd has grown to an estimated size of 197,000 animals – an increase of 28,000 caribou from the last estimate made in 2010.

The 2010 census found an estimated 169,000 animals in the herd – a significant increase over the previous census successfully conducted in 2001 which found 123,000.

The results come from a survey conducted last summer by the Alaska Department of Fish and Game in collaboration with the Yukon and Northwest Territories governments.

Alaskan officials and Environment Yukon staff used radio- and satellite-collared caribou to locate the large groups needed for the aerial census.

Joe Tetlichi, who chairs the Porcupine Caribou Management Board, spoke Wednesday of the efforts of the Porcupine Caribou Management Agreement signatories to develop and implement a management plan in recent years

"The board appreciates the positive actions that harvesters have taken in co-operation with the Harvest Management Plan,” Tetlichi said.

"This includes focusing on a bull-dominated harvest and, whenever possible, leaving the cows alone so they can reproduce and increase the overall herd size.”

The aerial census photographed caribou found in Alaska, the Yukon and the Northwest Territories.

After the numbers of caribou photographed were tallied, the final population estimate was calculated using a correction for the number of radio-collared caribou which were not photographed but were known to be alive at the time.

The next census to estimate the herd's size is expected to be held in June or July 2015.