The information below was written by Bob Sallinger, Conservation Director of Audubon Society of Portland. It’s a great summary of things you can do in your backyards for urban wildlife during the fall and winter.
You can start providing natural food and shelter by going easy on fall cleanup. There’s no need to be super neat and tidy- wildlife appreciates things a little on the wild side. Those fallen leaves that are starting to pile up or those unclipped flowers you meant to get to, can benefit birds and other wildlife. Flowers that have faded will still produce seeds and many birds will take advantage of them.
Leaving plant material (especially leaves) on the ground provide a great source of organic material for your soil. It also provides crawling spaces for reptiles, amphibians, and insects. In the winter, many ground-feeding birds like towhees and robins will thank you for those extra sources of insects. If you have a trimming project, collect branches and debris and make a brush pile in a corner of the yard. This provides a wonderful source of shelter for birds and wildlife on cold winter days.