The fire started Wednesday on the island of Mellum in Lower Saxony's Wattenmeer national park, Thomas Schumacher from the regional council said.
“The breedings grounds are as of now totally burned out,” Schumacher said.
Mellum was home to colonies of herring gulls and oystercatchers, but both were reportedly completely destroyed by the flames. Wildlife officials could not say how many of the marine birds perished in the inferno.
Thousands of birds breed on the island every year.
Over 20 emergency personnel were transported to the island by boat to fight the blaze. By late Wednesday evening, they had managed to extinguish it, though their efforts were made harder by the absence of water on the island. Officials do not yet know what started the fire.