Urbanization and biodiversity loss disconnect humans from nature and may limit pro-environmental actions. Although, a growing body of knowledge exists on people's attitudes towards nature, the majority focuses on the influence of socio-environmental factors. Significant variations in socioeconomic and educational levels in urban areas affect access to biodiversity. In this study, we aim to identify the socio-environmental variables that are associated with people's attitudes towards nature (student's knowledge about urban birds and their participation in conservation actions). We collected data on local biodiversity, socioeconomical status, and high school students' attitudes towards nature (15 schools, n = 175 students) in a large Latin American capital city. Structural equation modeling (SEM) was utilized to identify relationships among all variables. Socioeconomic characterization was assessed using levels of socio-materiality and school performance scores. Definitions of ecological complexity were based on bird species richness and vegetation density. Knowledge of urban birds was evaluated using two indicators: urban bird identification (recognition of names) and identification of the biogeographic origin of urban birds (native or exotic). Participation in conservation actions by students was assessed based on implementation scale and implementation frequency. According to our results, respondents' knowledge of birds was poor: 42% of students identified only two species (the domestic pigeon and the monk parakeet, both exotic). Only 26% of total students participated in conservation actions. SEM analysis revealed that socioeconomic status was positively associated with the ecological complexity of surrounding areas. In turn, ecological complexity showed a positive relationship with students' knowledge on urban birds. Finally, students' knowledge of urban birds showed a positive influence on conservation actions. Our findings suggest that, the improvement of students' knowledge about local biodiversity and ensuring equitable access to biodiversity could be an effective way to foster students' involvement in conservation actions, especially in neighborhoods of lower socioeconomic levels.