Terrestrial Animals
Description:
All SWAN parks possess intact, naturally functioning terrestrial ecosystems with their historic complement of species, including large carnivores. Such ecosystems containing historic levels of biodiversity are becoming extremely rare globally and supply a resource of great value locally and internationally. Some key wilderness-dependent mammals in SWAN are wolverines, wolves, and brown bears. These species do not require wilderness habitats per se, but they require wilderness to avoid conflicts with humans and to avoid human-caused mortality. They also depend on populations of free-roaming, naturally cycling prey such as moose and caribou.
Some terrestrial animals serve important ecological functions across systems. For instance, brown bears influence coastal intertidal community structure when they forage on salt marsh vegetation and clams, transfer nutrients from rivers to the land when they feed on spawning salmon, and influence plant distribution and nutrient availability when they dig in montane meadows. Bald eagles are keystone predators on avian and fish populations in both freshwater and marine nearshore systems. Eagles move salmon and other carcasses into riparian areas, and ravens and crows cache salmon bits in trees and under grass and rocks. Such marine-derived nutrients have the potential to significantly affect annual nutrient budgets and to maintain the long-term productivity of coastal river systems.
Large terrestrial herbivore-predator interactions are an intrinsic property of intact functioning ecosystems and are a flagship ecological feature of SWAN parks. Selective foraging by herbivores, such as caribou, can alter ecosystem functioning, change species composition, and modify nutrient cycling and plant productivity. Wolves are functionally important in this interaction because they exert top-down control of herbivores. Because caribou and wolf populations oscillate through time, herbivore-predator population cycles play an important role in maintaining a heterogeneous distribution of resources, or habitat mosaic. Caribou and moose also are important subsistence and cultural resources to local native Alaskans and provide significant recreational opportunities for resident hunters.
