Birds have been called “bellwethers of watershed health.” Because they respond to basic changes in landscape and habitat conditions, birds can be excellent indicators of watershed health.
Roger Tory Peterson, an American naturalist who published many books about birds and garnered multiple awards in his field, once said, “Birds are an ecological litmus paper. Because of their rapid metabolism and wide geographic range, they reflect changes in the environment quickly, and they warn us of things out of balance, sending out signals whenever there is deterioration in the ecosystem.”
GLA’s Watershed Biologist Rob Karner, a former ornithology instructor, helps the GLA monitor our bird variety, patterns, and health as a potential leading indicator of overall watershed health. The robust variety and health of our year-round resident birds and migratory birds point to a healthy watershed, and we want to introduce you to some of them.
This is a Bonaparte’s gull. These gulls like to rest on the tops of boat lift canopies. Bonaparte’s gulls are one of the smallest species of gulls and are affectionately known as the “dainty” gull, averaging 11 to 15 inches in length. Their plumage is mainly white with grey upperparts. During breeding season, Bonaparte’s gulls gain a slaty-black hood. The sexes are similar in appearance.
These gulls prefer to be on the treed edges of lakes, ponds, marshes, or islands. They typically nest within 200 feet of open water. They migrate in the spring to our watershed.
Their heads bob as they feed on the surface of the water, and they seem to work together in flocks of 15-20 as they feed. Like most gulls, Bonaparte’s gulls have a varied diet, with prey items changing over the course of the year and from year to year. During the breeding season, they are largely insectivorous. During migration and into the winter, insects are first supplemented, then replaced by other food items, including fish, small crustaceans, mollusks, euphausiids, marine worms, and other invertebrates.
The species is named after Charles Lucien Bonaparte, a French ornithologist and nephew to the former French emperor Napoleon Bonaparte, who spent eight years in America contributing to the understanding of the taxonomy and nomenclature of birds there and elsewhere.