Foods that you shouldn't feed to birds

Bird Mixes

The green and pink bits in some of the cheaper bird feed mixes are often crushed dog biscuits that will swell and absorb moisture as the bird tries to digest them.

Wheat and barley grains are only really suitable for doves and pigeons, which will have an adverse effect on the numbers of smaller birds in your garden.

Lentils, peas, rice and beans will attract the larger birds at the cost of many smaller species avoiding your garden.

• Cheap peanuts can contain a harmful toxin that can prove fatal if eaten by some birds
• Desiccated Coconuts can swell in the stomach and be fatal
• Spicy foods
• High-salt foods
• Salted nuts, bacon, crisps and snacks
• Margarine and Vegetable Oils
• Mouldy foods

Chocolate

Chocolate contains theobromine, which is toxic to birds 

Too much bread

Despite being a very popular source of food with many birds, bread provides little nutritional value and poses problems for the bird if it hasn't been thoroughly soaked prior to being fed to the birds.  In addition, if it is eaten frozen it can be equally fatal for the bird.