It's early Saturday morning and there are very few people about in Wren's Nest Retail Park, Glossop, Derbyshire. A mallard discreetly feeds her brood of ten on the path by the car park: a wonderful sight. Sadly, few from the brood will survive: much as the mother strives to protect her young, predators such as herons are waiting for when they can swoop down and take their prey. Humans are often harmful too, feeding birds bread, which not only bloats but can cause serious bone injuries to mallards and other birds. It is wholly selfish to feed birds bread when food for birds is openly available. Mallards also go for seedless grapes and chopped lettuce.