Abstract
In 1993, the first Japan breeding record for the Common Tern Sterna hirundo was obtained from a Little Tern colony located on a sand spit at the mouth of the Kurobe River, in Toyama Prefecture along the central Sea of Japan coast. 100 Common Tern were first sighted on May 13th, and at least one pair was observed to nest and breed. Incubation on May 18th, and the egg is thought to have hatched around June 10th. Immature was observed in flight on July 10th, and the terns disappeared between July 15th and 17th. The breeding site is well protected from most natural enemies by the surrounding water. In addition, the breeding Little Terns quickly raise the alarm at the approach of any potential predator. The Common Terns were also observed stealing food from the Lesser Terns.
