Perhaps you’ve heard the term “urban habitat” before. It refers to the phenomenon of wildlife inhabiting places designed for people—specifically places in cities. A famous case is the life and times of Pale Male, a falcon who decided to make news anchor Paula Zahn’s 5th Avenue apartment his home back in 1991 (and he’s still there). I collect images of such impromptu habitations wherever I find them. They are never designed, though rain water collection advocates, landscape architects, and various state fish and wildlife departments promote the idea. Mostly what I see are sparrows, sparrows everywhere! They’re small and compact and slip easily into gaps left by decaying mortar [image 1, left, the rotunda of the Pennsylvania RR Station in Pittsburgh, designed by Daniel Burnham], or alcoves in sculptural niches [image 2, middle, the facade of Sterling Memorial Library at Yale University], or intentional gaps in double facades [image 3, right, the American Folk Art Museum, New York City, designed by TWBTA]. I think these intrepid little fellows deserve our attention and admiration. They claim unused space and within it, breed new life. Would that all architects could do the same! I suppose this behavior makes sparrows scavengers of a sort, like hermit crabs that live in the discarded shells of snails. Animal architecture is an infinitely fascinating topic. Finnish architect Juhani Pallasmaa wrote a book about it: Animal Architects: Ecological Functionalism of Animal Constructions. Of the two examples most often cited, beaver dams and weaver bird nests, I’ve been fortunate enough to see the latter in Southbroom, a town on the south coast of KwaZulu-Natal province, South Africa. Beavers build their encampments with underwater entrances to protect themselves from predators, so one can’t easily see them at work. A weaver bird, however, weaves right in front of your eyes. ♦