52-58 cm, the male with dark green head and white neck, the female with reddish head. Present during wintering, it is frequent during the spring migration. It can be observed in coastal waters. even off a high coast, and in lagoons, preferably at the seagrass beds. Rare or absent in the inland wetlands and valli di pesca (fishing reserves). Some individuals pass the summer at the mouth of the Isonzo. The red-breasted merganser is a diving duck that feeds on fish and has a notched beak to help grip slippery organisms.