Here are details of a British scheme to encourage young people to help.
making-winter-habitats
More ideas
5-ideas-creating-winter-wildlife-habitat.htm
Build Warm Refuges
Tree branches, leaves, and other cuttings and wood pieces make great refuges for rodents, reptiles, and birds.
Rock piles with gaps also help.
Build a protective, warm and safe refuge out of your unwanted clippings, making sure to stack wood pieces with plenty of space in between them,
which will provide protection for rabbits, squirrels, and other small animals.
If you have a compost heap, this makes a wonderful place for grass snakes, slow-worms and toads.