The mallard feeds mainly on vegetable matter, which is usually obtained by upending (tipping head first into the water, so that the tail remains visible above the surface) (3). During autumn and winter they may feed in fields, some distance from water (3). Breeding may take place throughout the year, but usually occurs after March (4). In overcrowded water bodies, such as parks, breeding males may attack females in order to mate; this may lead to the death of the female in some cases. This behaviour is rare in truly wild mallards, however (6). The hollow nest, lined with grasses, feathers and leaves (5), is typically made close to water and is often concealed by vegetation (4). Between 10-12 pale green, blue or creamy white eggs are produced (although as many as 16 per clutch have been known), and are incubated for 28-29 days by the female (4). The downy chicks are led to the water by the female shortly after hatching and are cared for by the female for up to 8 weeks (4).