Deciduous forests are groves and heathland forests dominated by deciduous trees. The term also includes commercially managed, deciduous tree dominated forests. Typical tree species found in this category are birch, aspen, grey and black alder, and bird cherry. Many of the bird species inhabiting deciduous forests are content in managed forests. This is not the case, however, with the lesser spotted woodpecker, thrush nightingale and icterine warbler, who are more demanding in their quest for old-growth forest environments. Mature deciduous forests, with an ample shrub layer, provides a habitat for the richest bird life.