Cities as Designer Ecosystems

Having grown up reading Rachel Carlson's "Silent Spring" and watching empty lots and fields turn into shopping centers and housing developments, the quantity and variety of wildlife I stumble upon in my neighborhood travels constantly amazes me. Either the predicted ecological collapse fizzled, or the vacant lots and streams of my youth must have been knee-deep in wild creatures. What's going on?

An article at http://www.livescience.com/environment/050110_designer_ecosystem.html seems to offer some clues. Animals aren't only adapting to human environments, but whole new adaptive ecologies are developing, in many cases with greater populations than before.

If this is so, then there really may be more deer in Connecticut grazing on home gardens and decorative landscaping, then there were in the past when the best meal around was some tree bark. Or, putting a more subtle interpretion on it, the ecological wildlife issue isn't really population density, it's population diversity, and the resulting ability of those populations to withstand environmental stress through adaptation and growth.