This is in reference to the post regarding least terns nesting on warehouse roofs. About 30 years ago, and for about 10 years after that, a sizeable colony (~50 pairs) of Black Skimmers nested on a warehouse roof that could be seen from the Judge B. Smith overpass on Harbourside Drive in Galveston, Tx. One summer, the roof was resurfaced and the birds have never returned. So there may be surface features (gravel, tar, texture, slope) that would attract or deter nesting members of the tern family. There were lots of warehouses in the area, but this was the ony one utilized. It would be interesting to know what makes a roof desireable nesting realestate for these colony nesters so we could, as David suggested, find other nest sites in urban areas. Susan Knock in Galveston, Tx Susan L. Knock, PhD Instructional Assistant Professor, Marine Sciences Department Director, Office of Academic Enhancement Nerd-in-residence If your students can Google the answer, you are asking the wrong question.Edit your Freelists account settings for TEXBIRDS at //www.freelists.org/list/texbirds Reposting of traffic from TEXBIRDS is prohibited without seeking permission from the List Owner