<p>Rapid urbanization in cities often results in the loss of biodiversity and disruption of ecosystem processes. The remaining fragmented habitat contains fewer niches and resources and reduces the capacity to support viable populations. Increasing landscape connectivity has long been thought to limit the negative effects of habitat loss and fragmentation, and corridors linking habitat patches are often considered a practical solution. However, empirical tests of whether corridors increase biodiversity in the patches they link remain rare. Our study looked at forest patches in Baltimore City, Maryland, on the east coast of the United States, to assess whether forest corridors are associated with greater bird species richness and whether connectivity moderates the effects of urbanization. We predicted that connected patches would support greater bird species richness than isolated patches and that connectivity would become increasingly important in more urbanized landscapes. We surveyed birds at over 50 sites throughout Baltimore City: 33 isolated forest patches and 19 patches connected by a corridor. We then calculated patch size and landscape-level variables within 500&#xa0;m of point count sites and included them as covariates in analyses. We fit candidate models for species richness using general linear models and ranked them using AIC. The top model showed that bird species richness declined with increasing impervious surface cover in isolated patches but remained higher across this gradient in connected patches. Even small patches helped mitigate fragmentation effects, highlighting the conservation value of any forest patch, regardless of size. Our findings suggest that forest corridors may be one solution for increasing connectivity and biodiversity in cities.</p>