Recognizable by its flat U-shaped head, the Blue Whale calf weighs at birth, in early winter, no less than 2.5 tonnes for a size of 7 m. Drinking between 380 & 570 liters of milk daily, it can gain up to 90kg per day & double in length when it is weaned at the age of 7-9 months. Its diet is then mainly composed of small shrimp called krill.