In insular faunas, large-bodied species are thought to be extinction-prone due to small population sizes. We tested for biogeographic patterns of size-related avian occurrence on seven Neotropical land-bridge islands (Trinidad, Tobago, Margarita, Aruba, San Jose, Rey and Coiba). For each island, we classified breeding land-bird species into one of six non-overlapping size classes and compared size distributions to a source pool of adjacent mainland species. Both within and between avian families, there was a slight excess of large-bodied species on islands, compared to mainland source pools. Thus, there was no evidence that large-bodied species are extinction-prone and no evidence of size-related, ecological truncation at the family level. Neotropical land-bridge islands are separated from the mainland by relatively narrow water gaps, and there have probably been numerous opportunities for recolonization during the past 10,000 years of 'isolation'. Fifteen mainland species occurred on mesic land-bridge islands (Trinidad, Tobago, San Jose, Rey and Coiba) when- ever appropriate habitat was present. These persistent species were usually associated with second-growth, clear- ings, and residential areas. In contrast, thirty-two mainland species were never found on land-bridge islands in spite of the presence of appropriate habitat. These missing species were mostly associated with primary and second-growth forest. We believe that at least some of the species that never occur on land-bridge islands are extinction-prone. This list includes representatives from seventeen avian families and several diverse foraging guilds (e.g., insec- tivores, carnivores, and frugivores). The range of body masses spans almost three orders of magnitude (6-650 g). With respect to body size, we conclude that there are no simplified 'rules' for predicting the occurrence of most Neotropical bird species in insular communities. However, species that are often missing from land-bridge islands are primarily associated with primary or second-growth forest. These species may require additional autecological study to ensure their preservation in Neotropical parks.