The water flows into the ice cracks on the still-frozen rivers. Travelers must be wary of these dangerous conditions, which create large holes on the ice of the lakes and rivers. Both the high and lowland areas provide abundant habitat for the many species of migrating birds that nest and raise their young in these areas. For example, white-fronted geese can be found in the highland area, while cackling geese and black brant are often present in the lowland area. Swans also feed in the lowland lakes.
Cranes are common in both low and highlands.
Nunapik is found in the interior terrain. This is where rivers become fresh water, and salt water is not usually present. Another important feature of nunapik is sod, which the Cup ik people use for making sod houses. Sod also has many other uses. For instance, it can be used for building emergency shelters on the tundra.