His daily diet consists of 1.8 kgs of herring. Key Facts Male harbour seals are called bulls, and females are called cows. Harbour seals can sleep underwater. They will surface subconsciously to breathe. This ability is a result of an automatic cut-off characteristic of the seal's nervous system that prevents them from breathing at inappropriate times.
Harbour seals can detect prey using nerves in their whiskers to sense pressure changes in the water.
Toronto, Key Porter books Limited. King, Judith E. 1983. Seals of the World. New York, Comstock Publishing Associates. In Sea Frontiers.