Here is a snowy egret on the banks of a local river. There are 58 species in the egret and heron family, and 15 of them are found in Costa Rica.
It is possible to distinguish between snowy egrets and cattle egrets, which are also white, because snowy egrets have black legs and beaks, whereas cattle egrets have yellow or orange beaks and legs. Also, cattle egrets, which I have posted in the past, often flock in large numbers and often accompany cattle to eat bugs in the fields. Snowy egrets are usually seen along river banks stalking fish.