For total bird-versity, the jungle beats all. But in temperate zones, the wide variety of foods and nesting opportunities offered by suburban gardeners and landscapers attracts more birds than either densely populated cities or wild natural settings. This certainly seems to hold true at my house. Our lot is 1/3 acre; the house is in the middle. I did a count one dawn feeding time and identified ten different bird species just in my back yard just in a space of ten minutes.