These nestlings are ready to fledge. Next week when I look in this compartment they will probably be gone or if they are not gone just the act of opening the compartment may induce them to fledge. The Purple Martins here are at least week ahead in development compared to previous years. I haven't seen many nestlings at this stage of development in the past until the second half of July. Even last week, the first week of July, there were two or three compartments with nestlings near this stage of development.