A Bombardier DHC-8-315, JA720A operated by the Japan Coast Guard (JCG) took off from Naha Airport at 14:48 local time for marine patrol flight over the East China Sea with the destination to Ishigaki Airport. Immediately after the airplane made a left turn near Kitakojima Island, the pilot in command found four birds about 100 m ahead. However, there was no time to avoid the birds; accordingly, the airplane had head-on collision with one of them. The first officer also spotted the birds and tried to inform the captain; however, no time was left for him to do so. The event took place at 17:11 near Kitakojima Island at 1,000 ft when the airplane was flying at 170 kts. The pilot in command looking toward the nose from cockpit confirmed there was damage to the nose. He decided to abort the mission and headed for Ishigaki Airport, the destination. During the flight the indication of the left seat speedometer fluctuated more than that of the right one. Flight control system, engine and electric systems remained normal. The airplane uneventfully landed at the destination at 18:04. PROBABLE CAUSES: “In this accident the airplane sustained damage due to bird strike at 1,000 ft during marine patrol flight near Kitakojima island.”