The great crested grebe dives for fish, insects and invertebrate larvae, chasing prey under water by strongly swimming with its feet (5). Pairs begin to form during the middle of winter, and nesting can start in January, providing that conditions are mild (5). This grebe is well known for its elaborate courtship display, in which pairs raise and shake their head plumes, and approach each other with weed in their bills, rising up breast to breast in the water and turning their heads from side to side (4). The nest is either a hidden mound of reeds and other vegetation or else a floating platform anchored to vegetation (4). After May (4), between 1 and 9 (but usually 4) eggs are laid (6), which take 27-29 days to incubate (6). Both parents are involved in incubation; when they leave the nest they cover the eggs with rotting vegetation to keep them warm (4). After hatching, the stripy chicks are carried around on the backs of their parents, they fledge at around 71-79 days of age (10).