Cormorants are a duck-sized waterbird that eats fish.  They are closely related to pelicans, with 3 species that live in California.  The species that lives in McNabney and Moorhen marshes is the double-crested cormorant, which is named for two small tufts of feathers that stand on the top of their heads during breeding season.  Cormorants make nests near water, often very close to their neighbors, and lay 2 to 5 eggs.

When feeding, cormorants dive under water and use their feet to chase down the fish they eat.  The small hook on their bill helps them to catch and hold the fish, which are swallowed whole.  After feeding, cormorants will find a rock, tree, or electrical wire to stand on and will spread their wings.  This helps to dry their feathers, which when wet, makes flying very difficult.

About 100 years ago, cormorants were considered a food item by many, and their numbers declined greatly.  More recently, after widespread conservation efforts, cormorants have become very common, and are one of the easier birds to find in McNabney and Moorhen marshes.