Recently, the role of the modern day zoo has shifted away from ‘Ark’ style conservation towards more in-situ conservation and education. In-situ conservation often focuses upon exotic species and actions taken to conserve these species require extensive funding. A relatively unexplored and less costly form of conservation for zoos to become involved in is the promotion of free-living bird species within zoo grounds. However, within the peer reviewed literature there are few studies which describe free-living species across zoos and only one study (on free-living corvids) attempts to attribute factors within a zoo to the distribution of free-living species. The current study investigates factors affecting free-living bird abundances across multiple zoos. Over a period of seven months, four zoos were studied with 10 enclosures from each zoo being randomly selected for survey. Utilising point counts at an enclosure level, interactions of free-living bird species were recorded. Results highlight both cover within enclosures and the availability of subsidised feeding as significant factors in influencing free-living bird presence within. Further, results demonstrate that factors affecting bird presence and abundance are species specific, with access to subsidised food within an enclosure being significant for both house sparrows (Passer domesticus) and blue tits (Cyanistes caeruleus), but not for the robin (Erithacus rubecula). While the study presented is limited by sample size and survey effort, a novel approach in relating free-living bird presence to enclosure design is described, allowing for future studies to fully explore factors influencing free-living species distributions across zoo grounds. Utilising results from this study, zoos can begin to actively promote native bird conservation and further develop biodiversity action plans designed to encourage native species conservation within zoo grounds.