Spatial co-occurrence patterns are determined by environmental factors, such as food availability or habitat characteristics and by biotic associations. When resources are limited, competition which implies a dominant hierarchy can shape species assemblage. Here, we study space and time co-occurrence of steppe passerines during the breeding season in a natural steppe habitat, its modulation by environmental filtering, potential biotic interactions and random processes. We applied the joint species distribution model of hierarchical modelling of species community (HMSC) to data on species presence–absence and environmental, temporal and spatial covariates acquired from seven plots in a natural steppe in central Spain during two consecutive years. Our results reveal the patterns of bird species co-occurrence and suggest that this assemblage might be competitively structured. The assemblage appears to be configured around one dominant species, the Eurasian skylark, which establishes principally negative associations with many of the coexistent species. Our results contribute to the understanding of how competition and dominance processes, together with ecological constraints and other biotic associations, shape bird assemblages.