More than 100 species of migratory birds pass through New York City during spring and fall migrations. Located at the nexus of several migratory routes, New York City’s tall buildings and reflective glass pose a serious threat to over 100 species of migratory birds. Since 1997, NYC Audubon has led Project Safe Flight (PSF), a volunteer-based citizen-science project, with the goal of monitoring and mitigating bird collisions. We examined 16 years of PSF data, during which volunteers collected over 6,000 birds of 126 different species. The top two species, White-throated Sparrow and Common Yellowthroat, make up 23% of all collisions. The fall migration has a higher average number of collisions than spring. Distinct phenological trends in species composition are apparent, with American Woodcock making up the majority of early spring collisions and Dark-eyed Junco being the most common in late fall. Because birds may be overlooked by volunteers or be taken by scavengers or maintenance crews after collisions, we performed a persistence study and found that the recovery of bird carcasses was highly variable between sites. This ongoing study is important in developing a database of bird collisions to help elucidate and reduce the causes of urban bird collisions.