SOMBA K'E/YELLOWKNIFE - At the current rate of decline, statistics herald the impending extinction of the Bathurst caribou herd.

Since 1996, government reports suggest 317,103 caribou have vanished, averaging 24,393 animals per year.

When condensed to the past few years, statistics show the herd to be in a virtual freefall.

Since 2003, more than 154,109 caribou have disappeared, 95,000 in the past three years. That is an average of 32,050 animals each year, approximately 88 caribou each day.

Aboriginal traditional knowledge passed down through generations has played a key role in studying trends in herd fluctuations before modern-day statistical records were kept.

In a report released by the West Kitikmeot Slave Study in 2002 on the Kache Tue region, an area of land located on the East Arm of Great Slave Lake, northwest of Lutsel K'e, elders said caribou herds ebb and flow, but the rate of decline in recent history is unsettling.

"Elders have often commented that there are not as many caribou around today as in the past," the report reads. "This is of great concern to elders who have related the stories and predictions of their ancestors about how a decline in the wildlife would precede a time of immense change."

Morris Lockhart, a respected elder who had been living and hunting in the region since the 1920s prior to his 1999 interview for the study, commented on the decline of the once-abundant herd.

"In the past there were lots and lots of caribou," he told researchers. "The caribou don't cross as much at (Artillery Lake) as they used to. It's not only the caribou population that is decreasing. I am not sure if I will ever see large numbers of caribou again."

The conclusions of both modern-day science and traditional knowledge bode poorly for the future of the Bathurst herd, but neither seem able to determine the cause of the unprecedented changes. What is causing the Bathurst herd to dwindle? Is its chance of recovery fading with each passing day?

There are no simple answers to those questions.

Anne Gunn, a retired GNWT biologist who has spent more than 20 years of her career working with the Bathurst caribou, said increasing temperatures on the herd's 250,000 square kilometre range is the main catalyst for environmental change.

A report being finalized by the GNWT titled Environmental Trends Across the Bathurst Caribou Herd predicts "trends are for warming temperatures, increases in precipitation (although less precipitation is falling as snow)," and changes in the length of seasons.

The report suggests temperatures have risen since 1950. According to data from 22 weather stations in the Arctic eco-zone - which encompasses the Bathurst caribou's range - average summer temperatures have increased by 0.9 C and fall temperatures by 1.7 C.

"For the winter range of the herd, there is a measurable increase in winter temperature that is highly significant," Gunn said.

A study done in 1999 on the effects of climate change on the Bathurst caribou by scientists Janet Brotton and Geoffrey Wall, predicts increased snowfall beginning later in the winter and snow melt starting earlier in the spring, due to milder temperatures.

"These changes will have implications for caribou access to vegetation, for caribou movement, for the duration and intensity of insect harassment and for caribou health," the report said.

Gunn said an increase in precipitation is causing caribou difficulty when it comes to accessing food sources. Over the past 15 years, according to Environment Canada statistics, more rain is falling during September and October, when temperatures are cooler. More layers of ice and snow are appearing on the traditional winter range causing caribou to exert more energy.

"It's not statistically significant just yet," Gunn said, adding it's hard to measure a trend without more long-term data. "It looks like there is a greater frequency of freeze-thaw events. It makes it that much tougher for caribou to get through the winter. They have to spend more energy getting to the food."

And the more energy they spend searching for food, the less fat and energy they store up.

Hunters told the 2002 West Kitikmeot Slave Study, caribou hunted during the fall were not as healthy as they had been in previous years.

"I've shot three caribou and (they) were skinny and had pus in the meat - we couldn't even take much meat," one hunter said, adding when he went after two caribou "they didn't run away at all so I knew right away something was wrong."

Gunn said the makeup of food on the range is changing and the nutrients caribou are looking for are less accessible.

In the winter, caribou seek out lichen, which the caribou rely on when fresh, green vegetation is not available. Lichen allow the animals to access the nutrients they need, such as nitrogen which is used for protein synthesis and is vital to muscle development and milk production for pregnant cows preparing to nurse calves.

Gunn said between 1990 and 2000 the amount of calving ground occupied by lichen fell to 22 per cent from 44 per cent. Although the reasons are not fully understood, Gunn said it is possible an influx of other plant life, such as shrubs, are competing for nitrogen and consequently reducing lichen.

Although Gunn said the change in vegetation means an increase in grasses and small shrubs, green vegetation is not a viable source of food until the spring, meaning there is less nitrogen for the herd during the winter.

Gunn said while all these changes are happening, it's hard to classify how much each change might affect the herds. According to a GNWT report, calf-survival rate declined significantly between 2001 and 2004 to an average 20 per cent compared to 39.5 per cent between 1985 and 1996. During the same time period the calf-to-cow ratio also declined to approximately one calf for every five cows from two calves for every five cows.

"(There are) a series of trends that coincided with the decline of the caribou, but I can't say, (one thing) is 50 per cent of the change in calf survival," she said. "Here are all these trends happening and it's likely they are part of the mechanism for the decline but it's not simply cause and effect."

While traditional knowledge recognizes there have been environmental changes over the years, there is more concern about how resource development has influenced the Bathurst caribou range.

Aboriginal elders and hunters told the West Kitikmeot Slave Study caribou were moving south from the calving ground later than usual and with serious health issues, something they attributed to the NWT's three diamond mines located in the middle of the Bathurst range.

"The only way caribou change their migration route is when something is in the migration route. like the mine roads - that's the main factor."

A study on the effects of petroleum development on the Porcupine caribou herd in northern Alaska suggest resource development would likely affect calf survival, reduce weight of pregnant cows and calves, and, most significantly, reduce probability of conception during the fall months.

However, four days of workshops between the GNWT, aboriginal stakeholders and outfitters determined the diamond mines have a limited effect on caribou.

Studies on the effects of the diamond mines on caribou in the region found "there is a partial avoidance by caribou to a distance of 15 to 23 kilometres from each active mine. Mines encroach on between three per cent and eight per cent of the caribou range.

Elder Morris Lockhart said in all the years he has been hunting caribou, he has never seen injuries like what he has seen since the mines became active.

"Even when the caribou are running away from all the flies on the barren lands, we've never seen (it like) that," he said in 2000. "Even before I was hunting I went out with my dad and never saw a (caribou) foot with pus. I've been hunting for 80 years and I have never seen a caribou foot like that until today. Around this time the caribou are supposed to be really fat. They aren't supposed to be skinny like this."

Brotton and Wall's study suggest with a warmer climate, insect harassment might be more intense during the post-calving period in July, when caribou are attempting to rebuild their energy reserves for the migration south for the winter. Warble fly season begins in June, around the time of calving, and lasts through to August, but with warmer weather moving into mid-September, the warble fly season may be lasting longer.

Gunn said earlier green-up due to shifting weather, which provides more access to food for the caribou in the spring months, might be negated by increased insect harassment.

"The gain from the early green up from the warmer weather is lost because the caribou spend less time feeding and more time trying to escape the flies."

Without solid evidence to explain why the Bathurst herd has declined to a little more than 30,000 from 400,000 in the mid-1980s, there are those who question the validity of the claim.

"I don't think it's really happening," said John Andre, an outfitter from Montana who operates an outfitting business in the NWT and could be on the verge of losing his business if the Wek'eezhii Renewable Resource Board approves the management proposal put forward by the territorial government and the Tlicho government to eliminate the 750 outfitter hunting tags for the barren-ground herd.

"The science just doesn't add up," added Andre. "For that many caribou to disappear in the last three years, it's improbable."

A movement, comprised of mostly outfitters, believes the GNWT is misrepresenting the science to support the size of a decline, if there is one at all.

Since 2007, when the GNWT attempted and failed to eliminate the outfitter tags, which would have destroyed the $4-million outfitting industry, outfitters and resident hunters have battled the territorial government over the science and, as they see it, the false interpretation of a crashing caribou herd.

Next week, the third and final part in the series will look at the controversy surrounding the science and the argument the government is pushing a hidden agenda.