The common toad, also called escuerzo, is the largest amphibian in the Iberian Peninsula, with a robust and plump body. The female, larger than the male, can reach up to 20 centimeters in length, while the male does not exceed nine centimeters. It is easy to distinguish it from the racer toad because its parotid glands, the globular glands behind its eyes, are oblique rather than parallel. The eyes are reddish brown or orange with a horizontal pupil. Its muzzle is flat and round in shape. Its back may be brownish, sometimes coppery, sometimes greyish, and may have black spots and warts. The belly is light grey with dark spots. The fingers of its powerful hind limbs are of different lengths and have an interdigital palm that facilitates swimming. Although the species present in the Iberian Peninsula has traditionally been classified as the common European toad (Bufo bufo), it is now widely recognised as the subspecies Bufo spinosus. It can be found on all types of land on the peninsula, but it is more abundant in humid Spain, in leafy forests, up to an altitude of 2,500 metres, a few kilometres from some kind of water reservoir. Males reach reproductive maturity at three years and females at four. Beginning in February, they tend to gather in ponds and other pools of still water of a certain depth, where they were born, to breed. The reproduction takes place in spring. The males emit a characteristic sound, as a claim, during that period. They will spend a couple of weeks in the breeding area, during which time they will mate with several females. The laying consists of 2,000 to 7,000 black eggs in a double row, and is done in a single night per female. Tadpoles feed on algae and organic remains. They are diurnal and can be seen on the shores. In June, tadpoles metamorphose to toads, which will then be one centimetre long and begin their terrestrial life. It feeds on insects and other invertebrates, especially beetles, slugs and earthworms. If it feels threatened, it swells ostensibly to appear larger and deter a possible attack, it ducks its head and stretches out its hind legs. Most of its activity takes place at night, except during the breeding season. It is not a gregarious species during most of the year, so it is usually found alone, moving around in small jumps or walking. They spend their hibernation, from October onwards, buried superficially in the ground, although if there are periods of good weather, they can interrupt this hibernation. It is part of the diet of snakes, birds and mammals. Males can live up to 18 years, and females up to 21 years. Like all amphibians, it is a protected species, but unfortunately suffers from a high mortality rate due to roadkill. This species is very sensitive to biocides and phytosanitary products used in intensive agriculture and has therefore disappeared from many agricultural areas.