In short order we had seventeen new study sites, including business centers, multifamily housing units, and additional forest reserves. Don [Norman] began to survey these sites using the same point count techniques my students and I used in nearby residential and reserve areas.John M. Marzluff, Welcome to Subirdia: Sharing Our Neighborhoods with Wrens, Robins, Woodpeckers, and Other Wildlife (New Haven: Yale Univ. Press, 2014), p. 98
. . . When Don finished the summer's work, he reported rather sheepishly that a keen birder could expect to see equal numbers of species in forests of the Cascade Mountains and in Seattle's industrial heart. Though not as rich as residential subirdia, the three forests surveyed yielded an average of twenty-nine species, whereas the twelve business sites averaged thirty-one species. In fact, one-third of the business sites equaled or exceeded the diversity Don observed in the richest forest reserve.