The deer are browsers by nature, pulling off leaves from oak, birch and rowan trees. They will also eat twigs, ivy and lichen from trees, especially during the winter. In open habitats, the deer become mainly grazers, cropping grass and browsing from small shrubs such as heather. Feeding takes place mainly during the early morning and evening, the deer resting and ruminating (chewing the cud) by day. Red deer, like all ruminants, have a four chambered stomach to help digest their food.