The oaknut, or acorn, is the nut of the oaks and their close relatives (genera Quercus and Lithocarpus, in the family Fagaceae). It is enclosed in a tough, leathery shell, and borne in a cup-shaped cupule which usually contains a single seed (occassionally two). Depending on the species, acorns take between 6 and 24 months to mature; in which acorn morphology and phenology are important factors. They are generally 1–6 cm (0.39–2.36 in) long and 0.8–4 cm (0.31–1.57 in) broad. They also play an important role in forest ecology when oaks are the dominant species or are plentiful. Acorns, along with other nuts, are termed mast.The volume of the acorn crop may vary widely, creating great abundance or great stress on the many animals dependent on acorns and the predators of those animals. Wildlife that consume acorns as an important part of their diets include birds, such as pigeons, jays, some ducks, and several species of woodpeckers. Large mammals such as bears, pigs, and deer also consume large amounts of acorns and may constitute up to 25% of the diet of deer in the autumn. In Spain, Portugal and the New Forest region of southern England, pigs are still turned loose in dehesas (large oak groves) in the autumn, to fill and fatten themselves on acorns.
In this sub category you can download free PNG images: Acorn Food. In this category "Acorn" we have 9 free PNG images with transparent background.