Cotoneaster berries are considered poisonous. The come from an evergreen shrub called the cononeaster that is common throughout North America, and the bright orange or red berries grow in clusters along the branches.
The Cotoneaster berries are not edible for humans, according to the National Gardening Association. The Children's Hospital of Philadelphia website indicates that if eaten in large quantities, the berries from this plant can cause breathing difficulties, weakness or seizures, especially in children. The University of Utah Poison Control Center lists the toxicity of the Cotoneaster species as poisonous. Birds can eat the cotoneaster berries, as they are unaffected by the toxicity, but humans should avoid eating this berry.