This talk will probe key features of ecological science as a “transdiscipline” for these two important intellectual and practical realms. The conversation will be organized around the conundrum about pluralizing ecology. The term “ecologies” often evokes different reactions among natural scientists, compared to design professionals, scholars in the social sciences and humanities, and activists. The presentation will examine the contrasting structure and use of science implied by the plural and singular, relate those to the core and interdisciplinary margins of urban ecology, and exemplify how useful social-ecological models can emerge from the plural stance. Contrasting ecologies can be understood as resulting from different kinds and scales of co-production relevant both within science and beyond. Finding common ground between “ecology” and “ecologies” is important for transdisciplinary success.