It’s after people were spotted walking among herds over the weekend and offering food to the animals.
The Royal Parks charity says all visitors should observe a minimum 50 metre distance.
Deer are unpredictable and can weigh up to 200kg and reach speeds of up to 30mph.
Advice from The Royal Parks.
Red deer are the largest mammal native to the British Isles and in summer their coats are glossy red. Fallow deer are smaller and their summer coats, usually spotted, vary from a cream to darkish brown colour.
All male deer have antlers which start growing in the spring and are shed each year, usually at the end of winter.
Antlers are made of bone which can grow at a rate of up to 2.5cm a day. A soft covering known as velvet helps to protect newly forming antlers. It is then rubbed off by the male once growth is complete, in time for the rut in September.
