Brown pelicans are acutely vulnerable to oil spills due to their plunge-diving hunting technique and coastal nesting habits.
When pelicans dive through oil-contaminated water, the petroleum immediately compromises feather structure, eliminating insulation and buoyancy. Oiled pelicans suffer hypothermia, skin irritation, and ingestion of toxic hydrocarbons when preening. Chronic exposure to dispersed oil at lower concentrations also impairs reproduction and chick survival.