Extreme moose demographics in Gros Morne National Park, Newfoundland

The authors compare demographics and migration between two distinct ecoregions within Gros Morne National Park (GMNP) on Newfoundland's Great Northern Peninsula: the highland Long Range Barrens (LRB) and the lowland Coastal Plains (CP). Both ecoregions are well represented in the Park and also in a large portion of managed moose areas in the Province. Concurrent with Park establishment in 1973, hunting closure was followed by a local increase in the moose population, which first populated the Great Northern Peninsula in the late 1940s. While no change has been measured in densities of LRB moose in the Park during the past 25 years, densities of 14.6 moose per km² in 4% (very high stratum) and 6.1 moose per km² in 29% (high stratum) of the 1998 census area represent a substantial increase for the CP habitat. Calf production and yearling recruitment into GMNP were consistently higher in 1995-99 in CP relative to LRB habitat; evidence from herd composition surveys for the emigration of bull moose from the Park is also becoming apparent. For the same period, survival and migration were investigated with the use of VHF collars (n = 76) on calves and adults, and GPS collars (n = 12) on adults (total n = 48 LRB and n = 40 CP). Calf survival to 1 year differed significantly between the 2 habitats, lower in LRB (0.557) than in CP (0.718). In both habitats, the main cause of calf mortality was black bear predation (18% of all collared calves). Yearling survival to 2 years (0.793 LRB and 0.902 CP) and annual adult survival (0.817 LRB and 0.920 CP) also differed significantly between the 2 habitats. Several VHF-animals (at least 17) left the Park boundary, with extreme migration distances (>147 km) in some cases. Four GPS-collared moose left the Park boundary from highland areas in winter. GPS-ranges were consistently larger in LRB than in CP, and LRB ranges were more commonly used in summer. The habitats within the greater Park ecosystem apparently present very different carrying capacities, and GMNP area moose can be considered a single, dynamic population that crosses habitat and management boundaries. As a result, moose experience highly variable survival rates and migration patterns.