Because of a thunderstorm we were not able to control the colony. So we looked for fishing terns in the area around.
When flying over the surface of the water, the terns are watching if they can spot fish under the surface of the water. When the fish is the right size, the birds plunge headfirst into the water. Only fish that swim to about 0.5 m below the surface of the water can be captured. Sometimes juvenile fish are picked from the water surface.
Heavy waves, cloudy water or rain hamper the common terns when fishing. They are not able to see the fish under the water surface and wind makes it difficult to dive.
We do not know if some birds have fish species that they like most. If they catch always one species of fish, maybe this species is easier to capture at this time of year.