The availability of this food is most important during the winter when energy needs of the wildlife are the greatest and other food sources are scarce. Trees and shrubs which retain their fruit above the snowline throughout the winter can be an important source of food for wildlife. Insects are an important food for many birds during the breeding season. For instance, young sharptail grouse and Hungarian partridge feed almost exclusively on insects. As well, chickadees feed on insects which dwell in the crevices of tree bark.
Most migrating birds are insectivorous and use tree plantings for cover, nesting and feeding areas.
Those shelterbelts which attract insects will also attract songbirds. Ensuring that alternative food sources are available near the wildlife planting is also important. Some species such as pheasant, will only make effective use of tree cover if there is a food source nearby. Leaving small plots of standing grain near the planting site will improve the overall habitat of the area. Shelter Shelter is the most important component trees and shrubs contribute to wildlife habitat.