The reason for the possible closure in Newfoundland is that woodland caribou numbers there have fallen drastically over the last few years. The problem started in the early 2000s, when hunter trend data and herd survey indices indicated the caribou population on the island was declining. However, the data did not point to the causes of the decline, so in 2003 the Wildlife Division of Newfoundland Department of Environment and Conservation began a caribou calf mortality study that focused on survival rates for calves from several herds. They found that fewer than 10 percent of calves were surviving their first year. Later studies using intensive adult radio collaring and population assessments looked at season range distribution, habitat use, migration routes and the rate, timing and cause of adult caribou mortality. The bottom line of all this research was that the herd overall had dropped from a peak of over 90,000 in 1996 to a present population of only 37,000.
The natural adult mortality, meaning death by predation and causes other than hunting, was found to be about 12 percent. Combine that with a calf recruitment rate of less than 10 percent and you have a grim situation indeed. Those figures mean Newfoundland caribou populations will continue to decline independently of any other pressures, including hunting. The survival rate will have to increase to at least 15 percent just to stabilize populations at current levels.
The reason for such low calf recruitment is significant predation. Wildlife Division studies have clearly identified black bears, coyotes and in some cases lynx as the key predators of caribou calves. All focus on calves primarily from birth to 14 weeks........(continued)