You start with a birds-eye view of your property, using very simple, simply explained point-and-click mapping tools to draw in landscaping details. The program was developed by smart people at Cornell Lab of Ornithology. It's on the internet at www.yardmap.org and I highly recommend that you visit the site and play around with what it can do, learning as you go.
You'll learn a lot about the average yard. (Like how the typical lot is 20% house and driveway, 60% lawn, and a mere 20% left over for bird habitat) You'll learn a lot about your yard too; including getting a bunch of good, realistic landscaping ideas. I suggest you start by watching their "how to" video on the web site.
This is a "bird island"; one of thousands around the world - in all kinds of climates. Why do birds cluster on small islands like this (or on secluded beaches)?
There are two main reasons. The first of which is that no land predator (fox, bear, coyote etc.) can get to it. So the nest sites are less vulnerable.
Secondly, these places have steep cliffs, from which fledgling birds can jump and learn to fly. If unsuccessful, the landing is softened by the water.
There are other reasons, like early warnings from co-residents, and no humans' accessories (cars, paving etc.), but these are the main reasons why birds often cluster on small islands.