Nictau, New Brunswick
The Nepisiguit Highlands are part of the central highlands of Northumberland County, New Brunswick. Nictau is the nearest community, while Mount Carleton Provincial Park is located along the north border of the site. This mountainous and fairly remote region receives cold, snowy winters and hot, dry summers. The forests here are a patchwork of different ages, due to timber harvesting. The tree species found in uncut forest areas (about 50% of the area) are Balsam Fir and spruce. In the other half, most of which was clear-cut at some point over the last 20 years, White Birch, Balsam Fir and Pin Cherry dominate, with smaller amounts of spruce, Yellow Birch and various shrub species also being present. In a few locations Jack Pine has been planted.
The Nepisiguit Highlands are perhaps the most significant site in New Brunswick for breeding Bicknells Thrush. This species, recently designated as nationally vulnerable by the Committee on the Status of Endangered Wildlife, has a global population of between 5,000 and 15,000 pairs. Seventy-five Bicknells Thrush males have been recorded in these highlands (perhaps 1.5% of the worlds population). This is a minimum number; it is possible that there are many more thrushes breeding in these hills (up to perhaps 500 males if a larger surrounding area is included). Their preferred habitat at this site is 8-12 year-old regenerating stands at elevations above 500m.
Across most of their range, the Bicknells Thrush chooses high-altitude, dense coniferous forests that are structurally small and often stunted. Yet in Canada, the thrush is also found in young forests that have regenerated after logging. These forests are structurally similar to the thrushes typical habitat, which may be the reason that they are found there.
For this reason, clear-cutting as such is not a threat to Bicknells Thrush at this site and other similar sites in New Brunswick, Nova Scotia, and Quebec. But the changes that occur to cut forests as they get older are threats. Natural succession that leads to a less dense understorey, and stand thinning, a silvicultural practice that removes some young trees within a stand, both lead to structural changes in the forest that are unfavourable to the Bicknells Thrush. It may be that through time Bicknells Thrushes will be able to shift their nest locations from patches of forest that have become too old, to others that have been more recently cut.
The quantities of forest that are being clear-cut also need to be considered. It is thought that the amount of young regenerating forest will decrease at some point in the future as the annual area of logged forest decreases. This too may affect the breeding success of the Bicknells Thrush in areas were the species is breeding in non-traditional habitat.IBA Criteria Habitats Land Uses Potential or Ongoing Threats Conservation Status