| Since 1984, double-crested cormorant (Phalacrocorax auritus) nesting has been documented on the original span of the San Francisco-Oakland Bay Bridge (SFOBB). By 2007, the SFOBB colony had grown to become one of the largest in Northern California, with 800 nests. Following the Loma Prieta Earthquake in 1989, the California Department of Transportation (Caltrans) began planning the replacement of the original span. Recognizing that demolition of the original span would remove a critical, local, nesting site for the species, Caltrans constructed nesting platforms on the new span in the hopes that the colony would relocate. The nesting platforms were completed in 2009 and enticements were installed with the goal of relocating the colony to the new location. Enticements included decoys, audio broadcasts, nest boxes, and mirrors to mimic greater density on the platforms. As demolition of the original span began in 2014, the new nesting platforms sat unused as the colony held onto the remaining sections of the original span. On March 28, 2017, the final span of the original bridge was lowered, removing the colony's historic habitat. On April 5, 2017, the first cormorant observations on the new platforms were recorded. By May 2017, approximately 600-700 birds were observed roosting and nesting on the new platforms. The cormorants observed are likely from the same population that were using the original span. |