A field mark is a characteristic (e.g. in plumage) useful for species identification, usually birds. They are often used in field guides or identification keys. In a broader context, a field mark might be referred to as a character (e.g. "differential character" or "diagnostic character"). For birds this may include plumage, flight characteristics, proportions, voice, behaviour, etc., i.e., all characteristics that help identification. As opposed to in-hand marks, distinguishable when a specimen is held in the hand, field marks are especially those marks that remain useful in less than optimal conditions, for example when the subject is far removed, only partly visible or not sufficiently lit to see its colours.
The red-winged blackbird is a passerine bird of the family Icteridae found in most of North America and much of Central America. It breeds from Alaska and Newfoundland south to Florida, the Gulf of Mexico, Mexico, and Guatemala, with isolated populations in western El Salvador, northwestern Honduras, and northwestern Costa Rica. It may winter as far north as Pennsylvania and British Columbia, but northern populations are generally migratory, moving south to Mexico and the Southern United States. Claims have been made that it is the most abundant living land bird in North America, as bird-counting censuses of wintering red-winged blackbirds sometimes show that loose flocks can number in excess of a million birds per flock and the full number of breeding pairs across North and Central America may exceed 250 million in peak years. It also ranks among the best-studied wild bird species in the world. The red-winged blackbird is sexually dimorphic; the male is all black with a red shoulder and yellow wing bar, while the female is a nondescript dark brown. Seeds and insects make up the bulk of the red-winged blackbird's diet.
The American wigeon, also known as the baldpate, is a species of dabbling duck found in North America. Formerly assigned to Anas, this species is classified with the other wigeons in the dabbling duck genus Mareca. It is the New World counterpart of the Eurasian wigeon.
The white-faced ibis is a wading bird in the ibis family, Threskiornithidae.
The laughing gull is a medium-sized gull of North and South America. Named for its laugh-like call, it is an opportunistic omnivore and scavenger. It breeds in large colonies mostly along the Atlantic coast of North America, the Caribbean, and northern South America. The two subspecies are L. a. megalopterus — which can be seen from southeast Canada down to Central America — and L. a. atricilla, which appears from the West Indies to the Venezuelan islands. The laughing gull was long placed in the genus Larus until its present placement in Leucophaeus.
The European herring gull is a large gull, up to 66 cm (26 in) long. It breeds throughout the northern and western coasts of Europe. Some European herring gulls, especially those resident in colder areas, migrate further south in winter, but many are permanent residents, such as in Ireland, Britain, Iceland, or on the North Sea shores. They have a varied diet, including fish, crustaceans, as well as some plants, and are also scavengers, consuming carrion and food left by or stolen from humans.
The American golden plover is a medium-sized plover. The genus name is Latin and means relating to rain, from pluvia, "rain". It was believed that golden plovers flocked when rain was imminent. The species name dominica refers to Santo Domingo, now Hispaniola, in the West Indies.
The long-billed dowitcher is a medium-sized shorebird with a relatively long bill belonging to the sandpiper family, Scolopacidae. In breeding plumage, adults are characterized by a beautiful rufous head and underparts with a darker mottled back and a large white upper rump only seen in flight. They feed in various freshwater habitats with their bill underwater in a "sewing machine" motion and are known to have an exciting mating display where males chase females in flight. The genus, Limnodromus is Ancient Greek from limne, "marsh" and dromos, "racer". The specific scolopaceus is Neo-Latin for "snipe-like", from Latin scolopax, scolopacis, a snipe or woodcock. The English name is from Iroquois and was first recorded in 1841.
The short-billed dowitcher, like its congener the long-billed dowitcher, is a medium-sized, stocky, long-billed shorebird in the family Scolopacidae.
The ring-billed gull is a medium-sized gull. The genus name is from Latin Larus which appears to have referred to a gull or other large seabird. The specific delawarensis refers to the Delaware River.
The Chipping Sparrow is a species of New World sparrow, a passerine bird in the family Passerellidae. It is widespread, fairly tame, and common across most of its North American range.
The hairy woodpecker is a medium-sized woodpecker that is found over a large area of North America. It is approximately 250 mm (9.8 in) in length with a 380 mm (15 in) wingspan. With an estimated population in 2020 of almost nine million individuals, the hairy woodpecker is listed by the IUCN as a species of least concern. Some nomenclature authorities, such as the eBird/Clements checklist, place this species in the genus Dryobates.
Bird ringing (UK) or bird banding (US) is the attachment of a small, individually numbered metal or plastic tag to the leg or wing of a wild bird to enable individual identification. This helps in keeping track of the movements of the bird and its life history. It is common to take measurements and examine the conditions of feather moult, subcutaneous fat, age indications and sex during capture for ringing. The subsequent recapture, recovery, or observation of the bird can provide information on migration, longevity, mortality, population, territoriality, feeding behaviour, and other aspects that are studied by ornithologists. Other methods of marking birds may also be used to allow for field based identification that does not require capture.
The cliff swallow or American cliff swallow is a member of the passerine bird family Hirundinidae, the swallows and martins. The generic name Petrochelidon is derived from the Ancient Greek petros meaning "stone" and khelidon (χελιδών) "swallow", and the specific name pyrrhonota comes from purrhos meaning "flame-coloured" and -notos "-backed".
The alder flycatcher is a small insect-eating bird of the tyrant flycatcher family. The genus name Empidonax is from Ancient Greek empis, "gnat", and anax, "master". The specific alnorum is Latin and means "of the alders".
The bat falcon is a bird of prey in the family Falconidae, the falcons and caracaras. It is found in Mexico, Central America, Trinidad, and every mainland South American country except Chile and Uruguay.
Automatic identification and data capture (AIDC) refers to the methods of automatically identifying objects, collecting data about them, and entering them directly into computer systems, without human involvement. Technologies typically considered as part of AIDC include QR codes, bar codes, radio frequency identification (RFID), biometrics, magnetic stripes, optical character recognition (OCR), smart cards, and voice recognition. AIDC is also commonly referred to as "Automatic Identification", "Auto-ID" and "Automatic Data Capture".
The Indochinese green magpie, also known as the yellow-breasted magpie, is a small colorful bird native to the forests of China all the way to Vietnam.
The painted bunting is a species of bird in the cardinal family, Cardinalidae. It is native to North America. The bright plumage of the male only comes in the second year of life; in the first year they can only be distinguished from the female by close inspection.
The supercilium is a plumage feature found on the heads of some bird species. It is a stripe which runs from the base of the bird's beak above its eye, finishing somewhere towards the rear of the bird's head. Also known as an "eyebrow", it is distinct from the eyestripe, which is a line that runs across the lores, and continues behind the eye. Where a stripe is present only above the lores, and does not continue behind the eye, it is called a supraloral stripe or simply supraloral. On most species which display a supercilium, it is paler than the adjacent feather tracts.
The black-faced hawk is a species of bird of prey in the family Accipitridae. This low-density species has traditionally been believed to be restricted to Amazon Basin north of the Amazon River, but there are several records south of this river, in, for example, the Brazilian states of Pará and Acre, and southeastern Peru. It is closely related to the white-browed hawk and individuals showing a level of intermediacy between the two species are known, suggesting that they rarely hybridize