American red squirrels are primarily granivores, but incorporate other food items into their diets opportunistically.[6]
In the Yukon, extensive behavioral observations suggest white spruce seeds (Picea glauca) comprise over 50% of a red squirrel's diet,[9] but squirrels have also been observed eating spruce buds and needles, mushrooms, willow (Salix sp.) leaves, poplar (Populus sp.) buds and catkins, bearberry (Arctostaphylos sp.) flowers and berries, and animal material such as bird eggs or even snowshoe hare leverets (young).[10]