Information:  - Art is a diverse range of human activities in creating visual, auditory or performing artifacts (artworks), expressing the author's imaginative or technical skill, intended to be appreciated for their beauty or emotional power. In their most general form these activities include the production of works of art, the criticism of art, the study of the history of art, and the aesthetic dissemination of art.  - Gulls, often referred to as seagulls, are seabirds of the family Laridae in the suborder Lari. They are most closely related to the terns (family Sternidae) and only distantly related to auks, skimmers, and more distantly to the waders. Until the 21st century, most gulls were placed in the genus "Larus", but this arrangement is now known to be polyphyletic, leading to the resurrection of several genera. An older name for gulls is mew, cognate with German "Möwe", Danish "måge", Dutch "meeuw", and French "mouette"; this term can still be found in certain regional dialects.  - The black tern ( Chlidonias niger or Chlidonias nigra ) is a small tern generally found in or near inland water in Europe and North America . As its name suggests , it has predominantly dark plumage . In some lights it can appear blue in the breeding season , hence the old English name `` blue darr '' . The scientific name means `` like a swallow '' .  - The swallows and martins are a group of passerine birds in the family Hirundinidae that are characterised by their adaptation to aerial feeding. "Swallow" is used colloquially in Europe as a synonym for the barn swallow.  - A passerine is any bird of the order Passeriformes, which includes more than half of all bird species. A notable feature of passerines compared to other orders of Aves is the arrangement of their toes, three pointing forward and one back, which facilitates perching. Sometimes known as perching birds or, less accurately, as songbirds, the passerines form one of the most diverse terrestrial vertebrate orders, with over 5,000 identified species. It has roughly twice as many species as the largest of the mammal orders, the Rodentia. It contains more than 110 families, the second-most of any order of tetrapods (after Squamata, the scaled reptiles). The passerines contain several groups of brood parasites such as the viduas, cuckoo-finches, and the cowbirds. Most passerines are omnivorous, while the shrikes are carnivorous.  - Birds (Aves), also known as avian dinosaurs, are a group of endothermic vertebrates, characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a lightweight but strong skeleton. Birds live worldwide and range in size from the bee hummingbird to the ostrich. They rank as the class of tetrapods with the most living species, at approximately ten thousand, with more than half of these being passerines, sometimes known as perching birds or, less accurately, as songbirds.  - Terns are seabirds in the family Sternidae that have a worldwide distribution and are normally found near the sea, rivers, or wetlands. Previously considered a subfamily of the gulls, Laridae, they are now usually given full family status and divided into eleven genera. They are slender, lightly built birds with long, forked tails, narrow wings, long bills, and relatively short legs. Most species are pale grey above and white below, with a contrasting black cap to the head, but the marsh terns, the Inca tern, and some noddies have dark plumage for at least part of the year. The sexes are identical in appearance, but young birds are readily distinguishable from adults. Terns have a non-breeding plumage, which usually involves a white forehead and much-reduced black cap.  - The name marsh tern refers to terns of the genus "Chlidonias", which are typically found in freshwater marshes, rather than coastal locations. The genus name "Chlidonias" is from Ancient Greek "khelidonios", "swallow-like", from "khelidon", "swallow".  - Asia is Earth's largest and most populous continent, located primarily in the eastern and northern hemispheres and sharing the continental landmass of Eurasia with the continent of Europe. Asia covers an area of , about 30% of Earth's total land area and 8.7% of the Earth's total surface area. The continent, which has long been home to the majority of the human population, was the site of many of the first civilizations. Asia is notable for not only its overall large size and population, but also dense and large settlements as well as vast barely populated regions within the continent of 4.4 billion people.  - Europe is a continent that comprises the westernmost part of Eurasia. Europe is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, and the Mediterranean Sea to the south. To the east and southeast, Europe is generally considered as separated from Asia by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways of the Turkish Straits. Yet the non-oceanic borders of Europea concept dating back to classical antiquityare arbitrary. The primarily physiographic term "continent" as applied to Europe also incorporates cultural and political elements whose discontinuities are not always reflected by the continent's current overland boundaries.  - The Inca tern ("Larosterna inca") is a seabird in the family Sternidae. It is the only member of the genus "Larosterna".  - The Atlantic Ocean is the second largest of the world's oceans with a total area of about . It covers approximately 20 percent of the Earth's surface and about 29 percent of its water surface area. It separates the "Old World" from the "New World".  - Plumage ("feather") refers both to the layer of feathers that cover a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies, and may vary with age classes. Within species there can be different colour morphs.  - The Black Sea is a body of water between Eastern Europe and Western Asia, bounded by Bulgaria, Georgia, Romania, Russia, Turkey, and Ukraine. It is supplied by a number of major rivers, such as the Danube, Dnieper, Rioni, Southern Bug, and Dniester. The Black Sea has an area of (not including the Sea of Azov), a maximum depth of , and a volume of . It is constrained by the Pontic Mountains to the south and by the Caucasus Mountains to the east, and features a wide shelf to the northwest. The longest east-west extent is about .  - The barn swallow ("Hirundo rustica") is the most widespread species of swallow in the world. It is a distinctive passerine bird with blue upperparts, a long, deeply forked tail and curved, pointed wings. It is found in Europe, Asia, Africa and the Americas. In Anglophone Europe it is just called the swallow; in Northern Europe it is the only common species called a "swallow" rather than a "martin".  - A continent is one of several very large landmasses on Earth. Generally identified by convention rather than any strict criteria, up to seven regions are commonly regarded as continents. Ordered from largest in size to smallest, they are: Asia, Africa, North America, South America, Antarctica, Europe, and Australia. In geology, areas of continental crust include regions covered with water.  - A wetland is a land area that is saturated with water, either permanently or seasonally, such that it takes on the characteristics of a distinct ecosystem. The primary factor that distinguishes wetlands from other land forms or water bodies is the characteristic vegetation of aquatic plants, adapted to the unique hydric soil. Wetlands play a number of roles in the environment, principally water purification, flood control, carbon sink and shoreline stability. Wetlands are also considered the most biologically diverse of all ecosystems, serving as home to a wide range of plant and animal life.    What is the relationship between 'black tern' and 'marsh tern'?
The answer to this question is:
parent taxon