Living Sanibel: The Black Skimmer
The black skimmer’s nickname sea-dog comes from the barking sounds the bird makes as it glides over the water’s surface in search of minnows. The skimmer feeds in a most unusual fashion. It is the only bird in the world whose lower mandible (beak) is longer than the upper. It flies, generally in pairs or small groups, directly over the surface of the water with its extended lower bill slicing through the water. When it detects a fish or crustacean, it snaps its head down and snatches the creature directly from the water. Because of the constant wear on this extended lower mandible, the black skimmer’s bill continues to grow throughout its adult lifetime. Once again, this adaptation is unique to black skimmers and no other bird in the world has this ability.
North and South America are home to three races of skimmer. The northern population, Rynchops niger, is the only one that frequents the Southwest Florida coastline. Although its numbers in Florida are declining as a result of a lack of suitable nesting sites, the South American population of this same species, which prefers freshwater rivers and lakes to estuaries, is healthy. Two other species of skimmers inhabit Africa and India.
The skimmer tends to feed at dawn and dusk, a timeframe scientifically defined as crepuscular, and has even been known to feed nocturnally, especially under a full moon. The best place to view the skimmer is along the coastline in the late afternoon or anywhere in the back bays. One of the absolute best viewing spots in Southwest Florida to observe skimmers in action is Tigertail Beach on Marco Island, where they can sometimes be found in flocks numbering more than twenty birds. Another reliable viewing opportunity is just after dawn along the gulf beaches from Sarasota to Naples, but only when the air is very calm. The skimmer prefers very still water for feeding. It is monogamous and nests in colonies of other skimmers, generally on beaches, sandy islets, or sandbars.