The most extensive El Nino-related drop in Baja California brown pelican breeding in 30 years occurred this spring, UC Davis researchers report. Numbers of nests of the pelicans -- as well as of other marine birds in the Sea of Cortez and off the west coast of Baja California -- dropped sharply this year, says Dan Anderson, a UC Davis professor of wildlife, fish and conservation biology, who just returned from the area. "Literally a shutdown" is how Anderson terms the nesting failure. Working with UC Davis graduate student Eduardo Palacios and researcher James O'Keefe, Anderson estimated nests in colonies in the Sea of Cortez and off Baja. In preliminary surveys, the researchers found in one brown pelican colony, for example, that 280 nests existed in March and April sampling, but none could be found in May sampling; in a normal year, that colony would contain between 10,000 and 20,000 nests at each sampling. Osprey, the most resident of the breeding birds in the study area, in previous El Nino years have managed to still succeed in breeding, yet one-half to two-thirds of the nesting efforts were abandoned by May this year -- the most significant breeding drop-off recorded since 1971, Anderson said. Still, it was the most successful of nesting birds during this El Nino. Yet, the effect of El Nino conditions on marine bird nesting is exactly what Anderson thought he would find. "We expected a very strong effect, due to reduced food supplies and lack of breeding conditions," Anderson said. The seabirds cannot find enough prey such as sardines, anchovies and herrings when the ocean warms as it has done during this El Nino episode, Anderson says, making it hard for them to feed and reducing their likelihood of reproducing. Anderson and others expect to publish the results of the studies later this year. .