As a plant suitable for wildlife in hedgerows and useful in the kitchen for jelly and jam making since the fruit have a high pectin content for setting, you can do no better than the Wild Crabapple or Malus Sylvestris from the family Rosaceae. It is a tough small deciduous tree, native to Europe, which has been proven by DNA samples to have been an important contributor to the modern cultivated apple although there is another African species which also played a part in the genome and nowadays the Wild Crabapple are often planted in commercial apple orchards to assist with pollination as they have such long flowering periods.
Mentioned in Celtic folklore, the wood of Wild Crabapple was often burnt in fertility rites and the pips of the fruit tossed into the flames whilst saying the name of the person you love, if it was true love then the pips would explode. Wild Crabapple is a long-lived plant, possibly up to 100 years, which although called a tree more often grows as a bush or shrub making it eminently suitable for growing as part of a hedgerow.
The mid-green leaves which appear in spring are soon followed by clusters of sweetly scented white or pink tinged flowers, then developing into small yellowish green crabapples often used for jelly making. Malus Sylvestris, which literally translated means forest apple, is frequently included in native hedgerow mixes to encourage wildlife in the form of insects such as bees for pollination, an important function in the food chain, also birds and other mammals which eat the fruit, hence dispersing the seeds around the countryside. The truly wild Common Crabapple over time can develop thorns which can make it a good deterrent as part of a security hedge.
Malus Sylvestris will grow in any reasonable, well-drained soil, it is unsuited to wet sites, and for planting a hedge we would recommend 3 plants per metre for a single row and 5 plants per metre for a double staggered row to give more depth.