My “natural” versus “not natural” categorization sometimes blinds me to the ways of urban nature:

The development of Phoenix has, perhaps counter-intuitively, increased the total water permanence throughout the city when compared to the surrounding desert. This helps explain how Phoenix’s discrete blue spaces are able to subsidize such high levels of waterbird diversity and abundance. As long as the local habitat feature has the characteristics needed to support the community, features of the surrounding urban matrix are relatively unimportant.

That’s from “Waterbird community composition, abundance, and diversity along an urban gradient” by Andrade and colleagues in the latest issue of Landscape and Urban Planning. They surveyed birds in Phoenix, drawn by the water laid out upon the land. Birds are no dummies – where there’s water in the desert, they congregate.