Living Sanibel: Laughing gull found in Southwest Florida; herring gull found in North America
Known for its distinctive, laugh-like call, the laughing gull is the most common gull found in Southwest Florida. It dons a black cap during breeding season, but during most of the year is far less conspicuous, with a white head, gray wings, and blackish markings. The juvenile coloration is a mottled gray before reaching adult plumage in three years.
This gull gathers along the spoil islands, as well as almost anywhere along the beaches. It feeds on fish, crustaceans, insects, carrion, eggs, young birds, and refuse. It frequently raids unattended picnic grounds when the unsuspecting tourists head out for a swim. It may also sit atop a pelican’s head waiting for it to strain out the saltwater and feed on the overflowing minnows.
The laughing gull is monogamous and a strong colonial nester. In nearby Tampa Bay there are islands where up to 10,000 laughing gulls mate and nest at one time.
The herring gull is the quintessential gull in North America: a loud, raucous bird that is a frequent visitor to landfills and garbage dumps where it feeds on almost everything. In the wild it is an aggressive gull that steals food from other birds, feasts on dead fish and carrion along the shoreline, and surface-dives for fish, mollusks, and squid. In its northern nesting ranges it is also known to feed on tern eggs and chicks.
The herring gull is a migratory species in Florida with no known breeding pairs found in the state. Believe it or not, this plentiful gull was once brought to the edge of extinction through a combination of hunting it for its large, white and black wing feathers and harvesting its large eggs for human consumption. In 1900 the entire North American population was estimated at only 8,000 birds, all in Maine. By 1990, after decades of intense conservation efforts, the population in Maine stood at 27,000 but tens of thousands more had spread across its historic range from the Gulf of St. Lawrence to Alaska, and its numbers are now estimated to be in the millions. In the north this large gull is often in conflict with a similar, but larger bird, the great black-backed gull.
Among ornithologists considerable controversy surrounds the extended herring gull family. Once believed to be closely related to the European herring gull, recent DNA studies indicate this is not the case, and there is considerable debate over the relationship of the American herring gull to several other subspecies. The herring gull is known to hybridize with other species of gulls including the lesser black-back and the glaucous-winged gull, making the situation even more complex.
Most herring gull mortality arises from its close interactions with humans. In dump sites it is often killed by bulldozers pushing over piles of garbage, while at sea it becomes tangled in fishing line and nets, and considerable numbers of herring gulls die from toxicity from manmade chemicals and plastics. The nests and chicks are often raided by jaegers and black-backed gulls.
This is an excerpt from The Living Gulf Coast – A Nature Guide to Southwest Florida by Charles Sobczak. The book is available at all the Island bookstores, Baileys, Jerry’s and your favorite online sites.