Most people keep records of their finances and car maintenance.
Martin landlords should also keep records of their martin colonies not only for enjoyment but also to track the breeding success or failure of their birds. Martin house rooms and gourds should be numbered and records maintained on each nest. Plus you will have a history of your colony that you can share with other martin landlords. Such information is valuable in studying population trends and improving colony management techniques. Nest checks are an extremely important part of your colony management responsibilities.