Community Interactions

EMIGRATION

Migratory species such as waterfowl, shorebirds and caribou adapt to the tundra by avoiding the most severe conditions of winter. Each year at the end of the short growing season they move southward into the boreal forest or beyond, but return to the tundra to breed


Aperiodic emigration from the tundra is exhibited by the snowy owl during those years that the lemming populations have crashed. Those winters see snowy owl
Irruptions as far south as Virginia. Most owls are found with empty stomachs and do not survive to return to the Arctic.

The population distribution, how the organisms are dispersed, is "random," not uniform and even, in the tundra


Resource partitioning
is dividing similar resources so that different competing species that need that resource can coexist.


Competition
for resources is tougher in the tundra because of the low availability of resources, such as nutrients and sunlight.


An interesting phenomenon that is demonstrated more clearly in the tundra than other biomes are population cycles. While one species is at a peak, population wise, its competitor will be between peaks. An example of this is snowshoe hare and the lynx. The population cycle is about 3 to 4 years between peaks.


Predator-prey relationships
in the Tundra follow the normal pattern in whuch the primary consumers, for example the arctic fox, will eat secondary consumers, for example birds. The relationship is complicated by the fact the the bird is not only a prey but a predator. Birds eat grasshoppers and other insects.