Our actual backyard is pretty terrible--long and thin, with just a deck and grass.
But we're the last house on the street, so right next to us is a large area (well, large by DC-suburb standards) with grass, big trees, a small creek, and a basketball court. When my kids were younger and played outside, we used it like an extension of our backyard. All the trees in the top photo are in the common area, not our backyard. I don't seem to have a good picture of it, but it's about 5x larger than what you can see here.
And here's a view where you can see the house and all the trees, to redeem it from the terrible impression that the backyard photo leaves, LOL:
We get lots of birds and squirrels, and there's a neighborhood fox who we see a few times a year. That's about it for wildlife here--I think our population density is too high for much more unless you visit one of the parks nearby.