Rynchops – Skimmers

Skimmers' eyes have vertical slits that act as sunglasses, shielding their retinas from the glare of glittering water and sandy beaches

The bill of skimmers is indeed one of their most remarkable features. Unlike any other species of bird, skimmers have a much longer lower mandible than the upper one. This adaptation is perfectly suited to their feeding technique, which involves flying low over the water with the lower mandible slicing through the surface. When the bill touches a fish, the skimmer reflexively snaps its mouth shut, capturing the prey. This method of feeding is efficient and allows skimmers to feed at the surface of the water while in flight, primarily at dawn or dusk.

The plumage of skimmers is another distinctive trait, typically featuring sharp black and white contrasts that are reminiscent of a formal ‘business class’ attire. This coloration provides camouflage in their often open and sandy habitats, helping them blend with the bright light and shadows cast across the landscape. The Black skimmer has a black upper bill with a red base, while the African and Indian skimmers have lighter, more yellowish bills.

Skimmers’ eyes are also uniquely adapted for their crepuscular and nocturnal feeding habits. They have large pupils that are close to vertical slits in bright light, protecting their vision and reducing glare from the water’s surface. This adaptation allows them to locate and catch fish in a wide range of lighting conditions.

Another fascinating aspect of skimmer biology is their social behavior. Skimmers are colonial nesters, often found breeding in large groups on sandbanks and beaches. Their nests are simple scrapes in the sand, and both parents share the responsibilities of incubation and chick-rearing. The communal aspect of their nesting helps in predator deterrence and increases the survival chances of their young.