This American goldfinch ranges from the southwestern United States (near the coast, as far north as extreme southwestern Washington) to Venezuela and Peru. It migrates from the colder parts of its U.S. range.
The lesser goldfinch often occurs in flocks or at least loose associations. It utilizes almost any habitat with trees or shrubs except for dense forest, and is common and conspicuous in many areas, often coming near houses. It is common at feeders in the Southwest United States and will come almost anywhere with thistle sock feeders. Flocks of at least six birds will often be seen at feeders. It feeds mostly on tree buds and weed seeds; geophagy has been observed in this species.
The nesting season is in summer in the temperate parts of its range; in the tropics it apparently breeds all-year round, perhaps less often in September and October. It lays three or four bluish white eggs in a cup nest made of fine plant materials such as lichens, rootlets, and strips of bark, placed in a bush or at low or middle levels in a tree.
The moult occurs in two different patterns which coincide with the blackness of the upperparts quite well. Here too is a broad zone of intergradation. Pacific birds moult after breeding, and females shed a few body feathers before breeding too. Juvenile males shed more remiges than females when moulting into adult plumage. East of the 106th meridian west, birds moult strongly before breeding and replace another quantity of feathers afterwards, and post-juvenal moult does not differ significantly between the sexes. However, this seems dependent on the differing rainfall regimes; simply put, birds at least anywhere in the North American range moult most of their plumage at the end of the dry season and may replace more feathers at the end of the wet season.
Considered a Species of Least Concern by the IUCN due to its vast range, it nonetheless seems to be declining locally. For example, it is rare in the Ecuadorean Andes foothills.


Cisneros-Heredia, Diego F. (2006): "Notes on breeding, behaviour and distribution of some birds in Ecuador." Bulletin of the British Ornithologists' Club 126 (2): 153–164. PDF fulltext
Delgado-V., Carlos A. (2006): "Observación de geofagia por el Jiguero Aliblanco Carduelis psaltria (Fringillidae)." ["Report of geophagy in the Lesser Goldfinch C. psaltria (Fringillidae)".] Boletín de la Sociedad Antioqueña de Ornitología 16 (2): 31–34. [Spanish with English abstract] PDF fulltext
Howell, Steven N.G. & Webb, Sophie (1995): A Guide to the Birds of Mexico and Northern Central America. Oxford University Press, Oxford & New York. ISBN 0-19-854012-4
Peterson, Roger Tory; Peterson, Virginia Marie; National Audubon Society; National Wildlife Federation & Roger Tory Peterson Institute (1990): A field guide to western birds: a completely new guide to field marks of all species found in North America west of the 100th meridian and north of Mexico. Houghton Mifflin, Boston. ISBN 0-395-51424-X
Quatro, John (2007): Siskins of the World. Retrieved January 10, 2008.
Sibley, David Allen (2000): The Sibley Guide to Birds. Alfred A. Knopf, New York. ISBN 0-679-45122-6
Willoughby, Ernest J. (2007): Geographic variation in color, measurements, and molt of the Lesser Goldfinch in North America does not support subspecific designation [English with Spanish abstract]. The Condor 109 (2): 419–436. doi:10.1650/0010-5422(2007)109[419:GVICMA]2.0.CO;2


The American goldfinch (Spinus tristis) is a small North American bird in the finch family. It is migratory, ranging from mid-Alberta to North Carolina during the breeding season, and from just south of the Canada–United States border to Mexico during the winter.
The only finch in its subfamily to undergo a complete molt, the American goldfinch displays sexual dichromatism: the male is a vibrant yellow in the summer and an olive color during the winter, while the female is a dull yellow-brown shade which brightens only slightly during the summer. The male displays brightly colored plumage during the breeding season to attract a mate.
The American goldfinch is a granivore and adapted for the consumption of seedheads, with a conical beak to remove the seeds and agile feet to grip the stems of seedheads while feeding. It is a social bird and will gather in large flocks while feeding and migrating. It may behave territorially during nest construction, but this aggression is short-lived. Its breeding season is tied to the peak of food supply, beginning in late July, which is relatively late in the year for a finch. This species is generally monogamous and produces one brood each year.
Human activity has generally benefited the American goldfinch. It is often found in residential areas, attracted to bird feeders which increase its survival rate in these areas. Deforestation also creates open meadow areas, which are its preferred habitat.


The American goldfinch was one of the many species originally described by Carl Linnaeus in the landmark 1758 10th edition of his work, Systema Naturae, where he classified it in the genus Fringilla. It was later placed in the genus Spinus, a group containing New World goldfinches and siskins. In 1976, Spinus was merged into the genus Carduelis as a subgenus. Recent studies have resurrected the genus Spinus. Its closest relatives are the lesser goldfinch (S. psaltria), Lawrence's goldfinch (S. lawrencei), and the siskins. Although it shares a name with the European goldfinch, the two are in separate genera and are not closely related. Carduelis is derived from carduus, the Latin word for 'thistle'; the species name tristis is Latin for 'sorrowful'. There are four recognized subspecies of the American goldfinch:
The eastern goldfinch (S. t. tristis) is the most common of the subspecies. Its summer range is from southern Canada to Colorado, and east to the Carolinas. Its winter range is from southern Canada south to Florida and central Mexico.
The pale goldfinch (S. t. pallidus) is differentiated from other subspecies by its paler body color, stronger white markings and, in males, a larger black cap. It is slightly larger than C. t. tristis. The summer range is from British Columbia to western Ontario, south to Colorado and west to Oregon. In winter, the range extends from southern Canada and northern California, south to Mexico.
The northwestern goldfinch (S. t. jewetti) is smaller and darker than the other subspecies. It occurs on the coastal slope of the Cascade Mountains from southern British Columbia to central California, overlapping with the range of C. t. pallidus.
The willow goldfinch (S. t. salicamans) occurs west of the Sierra Nevada range during the summer and in the central and southern Baja California Peninsula to the Mojave Desert and the Colorado Desert in the winter. In winter, the plumage of both sexes is browner than the other subspecies and in summer, the male's black cap is smaller than that of the other subspecies.
This seems to be the most ancient extant species of the Meso-American Spinus/Carduelis evolutive radiation, whose parental species is Lawrence's goldfinch (Spinus lawrencei).


The American goldfinch is a small finch, 11–14 cm (4.3–5.5 in) long, with a wingspan of 19–22 cm (7.5–8.7 in). It weighs between 11–20 g (0.39–0.71 oz). Among standard measurements, the wing chord is 6.5 to 7.8 cm (2.6 to 3.1 in), the tail is 4.2 to 5.1 cm (1.7 to 2.0 in), the culmen is 0.9 to 1.1 cm (0.35 to 0.43 in) and the tarsus is 1.2 to 1.4 cm (0.47 to 0.55 in).} The beak is small, conical, and pink for most of the year, but turns bright orange with the spring molt in both sexes.
The shape and size of the beak aid in the extraction of seeds from the seed heads of thistles, sunflowers, and other plants.
The American goldfinch undergoes a molt in the spring and autumn. It is the only cardueline finch to undergo a molt twice a year. During the winter molt it sheds all its feathers; in the spring, it sheds all but the wing and tail feathers, which are dark brown in the female and black in the male. The markings on these feathers remain through each molt, with bars on the wings and white under and at the edges of the short, notched tail. The sexual dimorphism displayed in plumage coloration is especially pronounced after the spring molt, when the bright color of the male's summer plumage is needed to attract a mate.
Once the spring molt is complete, the body of the male is a brilliant lemon yellow, a color produced by carotenoid pigments from plant materials in its diet, with a striking jet black cap and white rump that is visible during flight. The female is mostly brown, lighter on the underside with a yellow bib. After the autumn molt, the bright summer feathers are replaced by duller plumage, becoming buff below and olive-brown above, with a pale yellow face and bib. The autumn plumage is almost identical in both sexes, but the male has yellow shoulder patches.
The immature bird has a dull brown back, and the underside is pale yellow. The shoulders and tail are a dull black with buff-colored, rather than white, markings on wings and rump. This coloration is the same in both sexes.
The song is a series of musical warbles and twitters, often with a long note. A tsee-tsi-tsi-tsit call is often given in flight; it may also be described as per-chic-o-ree. While the female incubates the eggs, she calls to her returning mate with a soft continuous tee-tee-tee-tee-tee sound. The young begin to use a call of chick-kee or chick-wee shortly before fledging, which they use until they have left the nest entirely. There are two defense calls made by adults during nesting; a sweet call made to rally other goldfinches to the nest and distract predators, and a bearbee used to signal to the nestlings to quiet them and get them to crouch down in the nest to become less conspicuous.


The American goldfinch prefers open country where weeds thrive, such as fields, meadows, flood plains, as well as roadsides, orchards, and gardens. It may also be found in open deciduous and riparian woodlands and areas of secondary growth. This habitat preference continues during the spring and autumn migrations.
The summer breeding range stretches across North America from coast to coast. It is bounded on the north by Saskatchewan and stretches south across North America to North Carolina on the east coast, and northern California on the west coast. The American goldfinch is a short-distance migrant, moving south in response to colder weather and lessened food supply. This responsive, southerly migratory pattern is thought to begin to occur as daily low temperatures approach freezing, and particularly as these temperatures near 0 °F. The migration is completed in compact flocks, which travel in an erratic, wavelike flight pattern.
Its winter range includes southern Canada and stretches south through the United States to parts of Mexico. In winter, in the northern part of its range, the finch may move nearer to feeders if they are available. In southern ranges, during winter, they remain in areas like fields and flood plains where they live during the summer months.
Attempts were made to introduce the American goldfinch into Bermuda in the 19th century and Tahiti in 1938, but the species failed to become established in either place.


The American goldfinch flies in a distinctive undulating pattern, creating a wave-shaped path. This normally consists of a series of wing beats to lift the bird, then folding in the wings and gliding in an arc before repeating the pattern. Birds often vocalize during the flapping phase of the pattern and then go silent during the coasting phase. The call made during flight is "per-twee-twee-twee", or "ti-di-di-di", punctuated by the silent periods. They communicate with several distinct vocalizations, including one that sounds like "po-ta-to-chip" to the listener.
Birds do not act aggressively toward predators within their territory; their only reaction is alarm calling. Predators include snakes, weasels, squirrels, and blue jays, which may destroy eggs or kill young, and hawks and cats, which pose a threat to both young and adults. The oldest known American goldfinch was 10 years and 5 months old.


The American goldfinch is gregarious during the non-breeding season when it is often found in large flocks, usually with other finches. The social hierarchy, measured by how many aggressive encounters are won by each individual, tends towards the male being dominant in the non-breeding season. During the breeding season, this finch lives in loose colonies. While the nest is being constructed, the male will act aggressively toward other males who intrude into his territory, driving them away, and the female reacts in the same way toward other females. This aggressiveness subsides once the eggs have been laid. The social hierarchy in the breeding season generally has the female dominant over the male. Dominance may change based on the value of a resource; a study published in 1987 found that starved subordinate birds were sometimes dominant in competitions over feeder access.
Birds indicate their level of aggression through a range of displays. The head-up display, where the neck and legs are slightly extended, shows mild aggression and is often performed by the victor of an encounter. The carpals-raised display has the neck retracted and the carpals raised; displayers are likely to attack their opponent. The head-forward display is where the legs are flexed, the neck extended, and the beak closed. At higher intensities, the neck is lowered, the beak is pointed at the opponent, and one or both wings are raised. In extreme cases, the neck is retracted, the bill opened, the body feathers sleeked, and the tail is fanned and raised slightly. Aggression is also displayed by showing the front of the body to another individual. Attacks include pecking at feathers, supplanting the opponent by landing next to it, and flying vertically with legs and feet extended, beaks open, and necks extended. Avoidance behaviors include showing only the side of the body to an aggressor, leaning away, flexing the legs, retracting the neck, and pointing the beak down.


The breeding season begins later in the year than for any other finch and later than any other native North American bird, besides occasionally the sedge wren. This may be related to the abundance of seeds in the late summer months, as seeds represent most of their diet.
The courtship rituals include aerial maneuvers and singing by males, who begin courtship in late July. The flight displays begin as the male pursues the female, who flies in zigzagging evasive patterns. The male can signal his quality and fitness, both in the short term (current body condition) and long term (genes), through ornamentation (bill color and plumage). If a female accepts the male as a mate, the pair will fly in wide circles, as the male warbles throughout the flight.
Once a male has found a mate, he selects a territory, marking the boundaries by warbling as he flies from perch to perch. After circling the perimeter, he performs two flight displays, first repeating a low, flat flight, then flying in an exaggerated version of normal flight, tucking his wings close to his body, plummeting earthwards and catching himself as he spreads his wings to glide upward in a series of loops. Two or three pairs may group their territories together in a loose colony, perhaps to aid in defense against predators.
The nest is built in late summer by the female in the branches of a deciduous shrub or tree at a height of up to 10 m (33 ft). The nest-building lasts approximately six days, during which time the female works in 10–40 minute increments. The male frequently flies with the female as she collects nesting materials, and though he may carry some materials back to the nest, he leaves its construction to the female. The outer shell of the nest is built of bark, weeds, vines, and grass. The inside diameter of the finished nest is about 6.5 cm (2.6 in). The rim is reinforced with bark bound by spiderwebs and caterpillar silk, and the cup is lined with plant down from milkweed, thistle, or cattail. The nest is so tightly woven that it can hold water, and it is possible for nestlings to drown following a rainstorm if the parents do not cover the nest.
The clutch is four to six bluish-white eggs, which are oval in shape and about 16 mm × 12 mm (0.63 in × 0.47 in), roughly the size of a peanut. It is thought that they are laid during the night. The eggs are incubated by the female alone, though the male brings her food as she nests, and most mating pairs raise only one brood each year.
The chicks hatch 12–14 days after incubation begins. Like all passerines, the chicks are altricial; they are hatched naked, with reddish bodies, pale grey down, and closed eyes. The mother bird feeds her young regurgitated seeds and insects as they grow. The hatchlings develop quickly, opening their eyes after three days, and completing the growth of olive-brown juvenile plumage after 11–15 days, at which time they begin to practice short flights close to the nest. For up to three weeks after fledging, they are still fed by the male, who locates them by listening for their fledging call. The chicks stop giving this call when they become entirely independent.
The American goldfinch is occasionally victim to brood parasites, particularly brown-headed cowbirds. One study found that 9% of nests had brown-headed cowbird eggs in them. It likely evades parasitism partly because of its late breeding season. The American goldfinch also makes a very poor host for brood parasites, with studies showing low hatching rates of brown-headed cowbird eggs and no fledging success. This is despite the lack of known behavioral adaptations against brood parasites in this finch. It is thought that the inability of brown-headed cowbird chicks to survive is due to a failure to get enough nutrition; the seed-rich diet of American goldfinch chicks varies from the usual insect-rich diet of other hosts.


The American goldfinch is a diurnal feeder. According to the Cornell Lab of Ornithology, the species is one of the strictest vegetarians in the bird world. It is mainly granivorous, but will occasionally eat insects, which are also fed to its young to provide protein. Its diet consists of the seeds from a wide variety of annual plants, often those of weeds, grasses, and trees, such as thistle, teasel, dandelion, ragweed, mullein, cosmos, goatsbeard, sunflower, and alder. However, it also consumes tree buds, maple sap, and berries. It will eat at bird feeders provided by humans, particularly in the winter months, preferring Niger seed (commonly and erroneously called thistle seed).
Unlike some finch species, the American goldfinch uses its feet extensively in feeding. It frequently hangs from seedheads while feeding to reach the seeds more easily. In the spring, the American goldfinch feeds on the catkins hanging from birches and alders by pulling one up with its beak and using its toes to hold the catkin still against the branch. This dexterity enables it to take advantage of food sources relatively inaccessible to potential competitors, increasing its chances of survival.


The American goldfinch has a large range, with an estimated global extent of about 11,300,000 km² (4,400,000 sq mi) and an increasing population. The species is evaluated as least concern on the 2016 IUCN Red List.


The American goldfinch is found in residential areas throughout its range. Backyard birders attract it using feeders containing niger seed, or by planting grasses and perennial plants, such as zinnias, cosmos, bee balm, or globe thistle, which produce seedheads favored by finches.
The American goldfinch is not threatened by human activity and is widespread throughout its range. The clearing of forests by humans, though harmful to many species, has benefited the American goldfinch. Clearing of woodlands causes declines in numbers of neotropical migrants, while favoring short-distance migrants and permanent residents. This benefits the American goldfinch both as a short-distance migrant, and because the created open areas are the preferred environment of the bird, where weeds thrive which produce the primary food source of the American goldfinch.


The American goldfinch is the state bird of Iowa and New Jersey, where it is called the eastern goldfinch, and Washington, where it is called the willow goldfinch. It was chosen by schoolchildren in Washington in 1951.


Spiraea splendens is a shrub of the rose family (Rosaceae) native to the western mountains of North America, from California to British Columbia, commonly known as dense-flowered spiraea, rose meadowsweet, rosy spiraea, subalpine spiraea, and mountain spiraea. It is commonly found at elevations between 2,000 and 11,000 feet on inland mountain ranges. The plant is adapted to cold, moist, rocky slopes, subalpine forests and meadows.
It is a woody shrub rarely reaching a meter in height. It has light green toothed leaves which turn yellow as cold weather approaches. The plant bears fragrant, fuzzy pom-poms of bright rosy pink flowers in the summer. The fruit is a tiny dry pod, no more than one eighth of an inch in length.
Native Americans made a tea-like drink from the leaves.


Spiranthes cernua plants grow up to 100 cm tall. They have 1-5 basal upright leaves, 5–22 cm long and 5–8 mm wide. The leaves are present during flowering but wilt afterwards. The white flowers are arranged in a spiral around the stem. Each flower is 6–12 mm long and consists of 3 sepals and 3 petals, all curved forward to give the flower a long bell shape. Flowers are slightly to strongly nodding (hence the name), older flowers usually nodding more than new ones. The dorsal sepal (the one at the top) is convex and recurved upwards towards the tip. The lip (bottom petal) curves strongly downwards towards its tip.
This species blooms in autumn.


Spiranthes cernua grows in wet meadows, mossy seeps, maritime dune swallows, Sphagnum areas around pond and lake edges and along roadsides.


Before more recent identification of several separate species Spiranthes cernua had long been described as a species complex, exhibiting different morphologies throughout its range. Charles Sheviak, now retired curator of the New York State Museum Herbarium, explored this diversity in great detail, eventually describing Spiranthes magnicamporum to represent large, later-flowering individuals with tuberous roots from the Midwest. More recently, molecular and morphological work has recognized additional cryptic species in need of description; these newly recognized species are sometimes not closely related to S. cernua.
Broadly, the Spiranthes cernua species complex includes:
Spiranthes arcisepala (Appalachian Mountains and eastern Great Lakes Basin)
Spiranthes bightensis (Atlantic ladies' tresses, ancient hybrid between S. cernua s.s. and S. odorata)
Spiranthes casei (Case's ladies' tresses)
Spiranthes cernua sensu stricto (described in this article)
Spiranthes incurva (ancient hybrid between S. cernua s.s. and S. magnicamporum, Great Lakes Basin, northern Ohio River Valley, and Great Plains)
Spiranthes magnicamporum (Great Plains ladies's tresses)
Spiranthes niklasii (ancient hybrid between S. cernua and S. ovalis, Ouachita Mountains and Crowley's Ridge, Arkansas)
Spiranthes ochroleuca (Appalachian Mountains and eastern Great Lakes Basin)
Spiranthes odorata (marsh lady's tresses)
Spiranthes parksii (Navasota ladies' tresses, in genetic studies revealed to be identical to S. cernua)
Spiranthes triloba (panther ladies' tresses)
Spiranthes ×kapnosperia (hybrid between S. cernua and S. ochroleuca, Great Smoky Mountains region)


A commonly cultivated variety is Spiranthes cernua 'Chadds Ford', grown because of its larger flowers, ease of cultivation, and other merits. This cultivar is also often labelled as Spiranthes odorata however botanically it is neither but a third species called Spiranthes bightensis.


Spiranthes magnicamporum, commonly called the Great Plains lady's tresses, is a species of orchid that is native to North America. It is primarily native in the Great Plains, but there are outlying populations in the east in areas of former natural grassland, such as the Black Belt prairies of the Southeast. It is found in both fens and wet and dry prairies, often in calcareous soil.
It is a perennial that produces a spiral of white flowers in the fall. It is closely related to the Spiranthes cernua complex, and it was not recognized as a separate species until the 1970s. S. magnicamporum can be distinguished by its much stronger scent, later flowering time, and lateral sepals that spread over the top of the flower.


The dickcissel (Spiza americana) is a small seed-eating migratory bird in the family Cardinalidae. It breeds on the prairie grasslands of the Midwestern United States and winters in Central America, northern Colombia, and northern Venezuela. It is the only member of the genus Spiza, though some sources list another supposedly extinct species (see below).


The dickcissel was formally described in 1789 by German naturalist Johann Friedrich Gmelin under the binomial name Emberiza americana. Gmelin based his description on Thomas Pennant's "black throated bunting" which Pennant had described and illustrated in 1785 in his Arctic Zoology. The dickcissel is the only species placed in the genus Spiza that was introduced in 1824 by French naturalist Charles Lucien Bonaparte. The genus name Spiza is the Ancient Greek word for a common type of finch, now assumed to be a chaffinch. The species is monotypic; no subspecies are recognised.
The dickcissel is part of a group of the Cardinalidae that also includes Amaurospiza, Cyanocompsa, Cyanoloxia, and Passerina. Spiza is the only one among these that lacks blue structural colors in its plumage. Though the color pattern and habits of the dickcissel make it stand apart from other Cardinalidae, its robust, cone-shaped bill – stouter than in American sparrows or true finches, which it somewhat resembles at first glance – gives away its relationships.


Dickcissels have a large, pale bill, a yellow line over the eyes, brownish upperparts with black streaks on the back, dark wings, a rust patch on the shoulders, and light underparts. Adult males have a black throat patch, a yellow breast, and grey cheeks and crown. This head and breast pattern is especially brilliant in the breeding plumage, making it resemble an eastern meadowlark. Females and juveniles are brownish on the cheeks and crown, and are somewhat similar in appearance to house sparrows; they have streaked flanks.
In flight, they make a low, "electric", buzzing fpppt. From an open perch in a field, this bird's song is a sharp dick dick followed by a buzzed cissel, also transcribed as skee-dlees chis chis chis or dick dick ciss ciss ciss.
Measurements:
Length: 5.5–6.3 in (14–16 cm)
Weight: 0.9–1.4 oz (26–40 g)
Wingspan: 9.8–10.2 in (25–26 cm)


Their breeding habitat is fields in midwestern North America. Following the breeding season the species migrates in large flocks to southern Mexico, Central America, and northern South America. They may occur as vagrants well outside of their normal range. From 1966 to 2015 the dickcissel experienced a greater than 1.5% population reduction in the northern part of its breeding range and throughout the Midwestern United States.


The birds migrate to their breeding range rather late, with the first arriving only in May, with most birds only arriving in early June. They nest near the ground in dense grasses or small shrubs, or up to 3–4 ft (91–122 cm) high in bushes and trees. Males may have up to six mates, with most attracting only one or two, and several failing to attract any mates at all. Yet if such "bachelors" survive until the next summer, they will get another try to attract females, as the partners only stay together for raising one brood. Dickcissels are thus among the few songbirds that are truly polygynous. When they leave for winter quarters by early August or so, what little pair bond existed during the summer is broken up.


Dickcissels forage on the ground or in fields. They mainly eat insects and seeds. Outside of the nesting season, they usually feed in flocks. They are considered a pest by farmers in some regions because flocks can consume large quantities of cultivated grains.
Dickcissel populations frequently fluctuate in numbers, even to the extent that their range changes notably. In the early 19th century, dickcissels expanded eastward, establishing a population in New England and the mid-Atlantic states that disappeared around the end of the century. Both appearance and disappearance were probably related to changes in land use.


The American tree sparrow (Spizelloides arborea), also known as the winter sparrow, is a medium-sized New World sparrow.
It had been classified under the genus Spizella, but multilocus molecular evidence suggested placement in its own genus.


Measurements:
Length: 5.5 in (14 cm)
Weight: 0.5-1.0 oz (13-28 g)
Wingspan: 9.4 in (24 cm)
Adults have a rusty cap and grey underparts with a small dark spot on the breast. They have a rusty back with lighter stripes, brown wings with white bars and a slim tail. Their face is grey with a rusty line through the eye. Their flanks are splashed with light brown. They are similar in appearance to the chipping sparrow. Due to this, they are sometimes also called the winter chippy.
Their breeding habitat is tundra or the northern limits of the boreal forest in Alaska and northern Canada. They nest on the ground.
These birds migrate into southern Canada and the United States to spend the winter. Usually, chipping sparrows are moving south around the same time as these birds arrive.
These birds forage on the ground or in low bushes, often in flocks when not nesting. They mainly eat seeds and insects, but also eat some berries. They are commonly seen near feeders with dark-eyed juncos.
This bird's song is a sweet high warble descending in pitch and becoming buzzy near the finish.


Naugler, C. T. 1993. American Tree Sparrow (Spizella arborea). In The Birds of North America, No. 37. (A. Poole, P. Stettenheim, and F. Gill, Eds.). Philadelphia: The Academy of Natural Sciences; Washington, DC: The American Ornithologists' Union.


Heydweiller AM. Ph.D. (1936). LIFE HISTORY OF THE TREE SPARROW, SPIZELLA ARBOREA. Cornell University, United States, New York.
Naugler CT. M.Sc. (1992). Effects of the acoustic environment on song structure and song recognition in the American tree sparrow (Spizella arborea). Queen's University at Kingston (Canada), Canada.


The white-cheeked starling or grey starling (Spodiopsar cineraceus) is a passerine bird of the starling family. It is native to eastern Asia where it is a common and well-known bird in much of its range. Usually, it is placed in the genus Spodiopsar.


White-cheeked starlings are 24 cm in length. The adult male is mainly dark grey-brown with a paler belly and a whitish band across the rump. The head is blackish with whitish cheeks and forehead. There is a white border to the tail and white markings on the secondary wing feathers. The legs are pale orange and the bill is orange with a black tip. Adult females are similar to the males but paler and duller.
The juvenile is brown with pale cheeks and rump and no black tip to the bill.
The loud, monotonous call is a series of harsh, creaking notes.


The adult moths are 32 to 40 millimetres (1+1⁄4 to 1+1⁄2 in) wing tip to wing tip, with a brown or gray forewing, and a white hindwing. There is slight sexual dimorphism, with males having more patterns and a distinct white spot on each of their forewings. The first larval instar is light colored with a larger dark head. As they develop through instars, they become browner with white lengthwise lines. They also develop dark spots with spines.


The fall armyworm's life cycle is completed within 30 days during summer, and 60 days during the spring and autumn seasons; during the winter, these caterpillars' life cycle lasts about 80 to 90 days. The number of generations a moth will have in a year varies based on climate, but in her life span a female will typically lay about 1,500 eggs. Because larvae cannot enter into diapause they cannot survive cold temperatures.


Fly and wasp parasitoids target the fall armyworm, most commonly Archytas marmoratus, Cotesia marginiventris, and Chelonus texanus. The armyworm is also vulnerable to additional parasitoids, varying with location. In 2018, egg parasitoid wasps of the genera Telenomus and Trichogramma were discovered to attack army worm eggs in East Africa.Cotesia icipe is another African braconid wasp suitable for the biological control of this lepidoptera.


Fifty-three different parasite species have been discovered in fall armyworm larvae, spanning ten different families. Often larvae can survive through much of their crop consumption despite outbreaks of disease, because of the larva's fast life cycle. Despite this, parasites of the fall armyworm are being studied extensively as a means of fighting armyworm attacks on crops. One suggested approach would be to introduce parasites from South America to North American fall armyworms, and vice versa.


Spoladea recurvalis, the beet webworm moth or Hawaiian beet webworm, is a species of moth of the family Crambidae. It is found worldwide, but mainly in the tropics.
The wingspan is 22–24 mm. The moth flies from May to September depending on the location.
The larvae feed on spinach, beet, cotton, maize and soybean. They feed on the underside of the leaves protected by a slight web. The larvae are green and resemble the ribs of the leaf somewhat. When fully grown, they are about 19 mm long.
The pupa is formed within a slight cocoon in a folded piece of leaf. It is very pale brown. The pupal period lasts about 12 days. Adult moths are nectarivores and capable of long-distance flights.


The double-collared seedeater (Sporophila caerulescens) is a species of bird in the family Thraupidae.
It is found in Argentina, Bolivia, Brazil, Paraguay, Peru, and Uruguay, as well as the southern border of Colombia on the Amazon River.
Its natural habitats are subtropical or tropical moist shrubland, pastureland, and heavily degraded former forest.


It is a dimorphic species, with the male having a gray head and back, a black-collared throat, paired with a black band just below, across the upper whitish breast. It has gray legs, a medium length tail, and the stout bill for seed-eating. The female is less colorful.


The species ranges from central Argentina east of the Andes cordillera northwards through Bolivia and Paraguay, and northeastwards into south-central Brazil, and southeast coastal Brazil; the species retreats into Amazonia during the austral winter. The double-collared seedeater is only found in the southern Amazon Basin, limited by the Amazon River as its northern limit.
In the west Amazon Basin it is found in eastern regions of Peru, the Ucayali River areas, and mostly the eastern bank of the north-flowing river. In the southeast Basin, it ranges from the Cerrado into the upstream two-thirds of the north-flowing Araguaia-Tocantins River drainage system.


The yellow-bellied seedeater (Sporophila nigricollis) is a species of bird in the family Thraupidae, formerly placed with the American sparrows in the Emberizidae.


The hooded seedeater was a proposed bird species described by Austrian ornithologist August von Pelzeln as Spermophila melanops in 1870. The only known individual was heavily moulted and caught in October 1823 from a flock of other seedeater species at the edge of a lake 15 kilometres north of Registro do Araguaia, Brazil. It is now considered to be either a hybrid or an abnormal specimen of the yellow-bellied seedeater. The bird had a black crest and throat, the upperparts were olive and the underparts showed a dingy buff. In contrast, a typical yellow-bellied seedeater has pale yellow underparts and the black colouring extends to the upper breast.


The yellow-bellied seedeater is found in Central and South America from Costa Rica to Bolivia. Its natural habitats are subtropical or tropical high-altitude shrubland, pastureland, and heavily degraded former forest.


One study in Brazil, estimated that 16,800 yellow-bellied seedeaters are illegal caught and sold as pets annually.


The cinnamon-rumped seedeater (Sporophila torqueola) is a passerine bird in the typical seedeater genus Sporophila.


This species is one of two resulting from the split of the former white-collared seedeater. The other former white-collared seedeater subspecies are now known as Morelet's seedeater. Genetic studies show that the cinnamon-rumped seedeater is more closely related to other Sporophila seedeaters than it is to Morelet's seedeater. There are two subspecies:
S. t. torqueola is found in southern Baja California and western Mexico.
S. t. atriceps is found in central and southwestern Mexico.


The cinnamon-rumped seedeater is endemic to western Mexico. It mainly inhabits tropical and subtropical grasslands, savannas, and shrublands but can also be found in pastures, arable land, and heavily degraded former forests.


The cinnamon-rumped seedeater eats mainly seeds and insects, and occasionally berries. It frequently forages on top of herbaceous plants, and less often on the ground.


Stachys bullata is a species of flowering plant in the mint family known by the common name California hedgenettle.


It is endemic to California, where it is known from the Central Coast Ranges, the Transverse Ranges, and other coastal mountain ranges in the central and southern parts of the state. It can also be found in maritime coastal habitat, such as the canyons of the Channel Islands.


This mint produces an erect stem up to about 80 centimeters tall. It is coated in rough and soft hairs, some glandular. The hairy, glandular leaves are up to 18 centimeters long, borne in opposite pairs along the stem. The hairy, glandular inflorescence is made up of interrupted clusters of six flowers each. The flower has a tubular pink corolla up to a centimeter long borne in a hairy calyx of sepals.


Stachys byzantina (syn. S. lanata), the lamb's-ear (lamb's ear) or woolly hedgenettle, is a species of flowering plant in the mint family Lamiaceae, native to Armenia, Iran, and Turkey. It is cultivated over much of the temperate world as an ornamental plant, and is naturalised in some locations as an escapee from gardens. Plants are very often found under the synonym Stachys lanata or Stachys olympica.
Lamb's-ear flowers in late spring and early summer; plants produce tall spike-like stems with a few reduced leaves. The flowers are small and light purple. The plants tend to be evergreen but can "die" back during cold winters and regenerate new growth from the crowns.


Lamb's-ears are herbaceous perennials, usually densely covered with gray or silver-white, silky-lanate hairs. They are named lamb's ears because of the leaves' curved shape and white, soft, fur-like hair coating. Flowering stems are erect, often branched, and tend to be 4-angled, growing 40–80 cm tall. The leaves are thick and somewhat wrinkled, densely covered on both sides with gray-silver colored, silky-lanate hairs; the undersides are more silver-white in color than the top surfaces. The leaves are arranged oppositely on the stems and 5 to 10 cm long. The leaf petioles are semiamplexicaul (the bases wrapping halfway around the stem) with the basal leaves having blades oblong-elliptic in shape, measuring 10 cm long and 2.5 cm wide (though variation exists in cultivated forms). The leaf margins are crenulate but covered with dense hairs, the leaf apexes attenuate, gradually narrowing to a rounded point.


The flowering spikes are 10–22 cm long, producing verticillasters that each have many flowers and are crowded together over most of the length on the spike-like stem. The leaves produced on the flowering stems are greatly reduced in size and subsessile, the lower ones slightly longer than the interscholastic and the upper ones shorter than the verticillasters. The leaf bracteoles are linear to linear-lanceolate in shape and 6 mm long.
The flowers have no pedicels (sessile) and the calyx is tubular-campanulate in shape, being slightly curved and 1.2 cm long. The calyx is glabrous except for the inside surface of the teeth, having 10 veins with the accessory veins inconspicuous. The 2–3 mm long calyx teeth are ovate-triangular in shape and are subequal or the posterior teeth larger, with rigid apices. The corollas have some darker purple tinted veins inside; they are 1.2 cm long with silky-lanate hairs but bases that are glabrous. The corolla tubes are about 6 mm long with the upper lip ovate in shape with entire margins; the lower lips are subpatent with the middle lobe broadly ovate in shape, lateral lobes oblong. The stamen filaments are densely villous from the base to the middle. The styles are exserted much past the corolla. There are immature nutlets without hairs, brown in color and oblong in shape.


Lamb's-ear is a commonly grown plant for children's gardens, as it is easy to grow and the thick felt-like leaves are fun to touch. It is also used as an edging plant. In Brazil it is used as an edible herb, called peixinho-da-horta prepared battered and deep-fried sprinkled with lemon juice and said to taste fish-like. It has sometimes been used as a medicinal plant.
A number of cultivars exist including white flowering forms, plants with shorter habit and plants that do not bloom as much:
'Big Ears' - leaves very large, up to 25 cm long.
'Cotton Boll' - a sterile cultivar that does not produce flowering stems. Asexually propagated.
'Primrose Heron' - leaves yellow in spring; flowers pink
'Sheila Macqueen' - sterile; low-growing; leaves large.
'Silky Fleece' - grows 25 cm tall with lilac-plum flowers, produce smaller white-woolly foliage. Seed propagated.
'Silver Carpet' - sterile; leaves grey. Asexually propagated.
'Striped Phantom' - leaves variegated.
Lamb's Ear is quite popular for a multitude of insects and Hummingbirds but in particular bees.  One special type of bee known as the Wool Carder Bee collects the fuzz off of the Lamb's-Ears leaves to use for making nests in decayed wood.  It has also been documented that bumble bees like to congregate in morning hours to collect water in the form of condensation that collects on the fuzz of the Lamb's-Ears leaves.


Stachys byzantina extract has shown antimicrobial activity against Staphylococcus aureus that is resistant to vancomycin.


Stachys chamissonis is a species of flowering plant in the mint family known by the common name coastal hedgenettle. It is a perennial herb native to the west coast of North America, where it grows in moist coastal habitat from Alaska to central California. This mint produces an erect stem 1 to 2+1⁄2 meters (3.3 to 8.2 ft). It is hairy, glandular, and aromatic. The oppositely arranged leaves have pointed, wavy-edged blades up to 18 centimeters (7.1 in) long which are borne on petioles. The hairy, glandular inflorescence is made up of interrupted clusters of up to six flowers each. The flower has a deep pink tubular corolla which can be over 3 centimeters (1.2 in) long. The corollas are borne in hairy calyces of purple or purple-tinged sepals.


Stachys coccinea, the scarlet hedgenettle or Texas betony, is an ornamental plant of the family Lamiaceae, which is native from Arizona to Texas and from Baja California Sur, Mexico to Nicaragua.
Some cultivars of this species include:
Stachys coccinea 'Chinook' - long blooming plants, coral-red colored flowers, plants grow around 40 cm (15 in) tall.
Stachys coccinea 'Hidalgo' - coral-red flowers, grows 30–45 cm (12–18 in) tall, sometimes listed under Stachys albotomentosa.
Stachys coccinea 'Hot Spot Coral' - coral-red colored flowers, plants grow 45 cm (18 in) tall.
Stachys coccinea 'Pow Wow' - brick-red colored flowers on plants growing about 30 cm (12 in) tall.


Stachys floridana is a species of betony in the mint family, Lamiaceae. It is native to the United States, where its true native range is probably limited to Florida, but today it is known throughout the Southeast as an introduced species and common weed. It occurs as far west as Texas, and it has been recorded in California. Its common names include Florida betony, Florida hedgenettle, and rattlesnake weed. It has been called wild artichoke, but it is not closely related to artichoke. The plant was the Florida Department of Agriculture's "Weed of the Month" for February 2010.


This species is a perennial herb producing a hairy, erect stem up to about half a meter in maximum height. It grows from a network of rhizomes with tubers. The distinctive pale-colored tuber is several centimeters long and about one centimeter wide, and is segmented in such a way that it resembles the rattle on the tail of a rattlesnake, the inspiration for the common name "rattlesnake weed". The tuber is also said to resemble "a fat grub". The tuber can reportedly grow up to one meter long in sandy soils. The oppositely arranged leaves have blades up to 5.5 centimeters long borne on petioles up to 3.5 centimeters long. Flowers grow in clusters of 3 to 6 from the upper leaf axils. The tubular, hairy calyx of sepals has pointed lobes. The two-lipped corolla is up to 1.3 centimeters long and white to pink with purple spots or darker lines. The fruit is a schizocarp a few centimeters long that splits in half. The seeds are about a millimeter long.


The plant is a prolific producer of seeds, but it often undergoes vegetative reproduction via its rhizome and tubers. Small segments of rhizome can sprout into new plants, and the transport of the tuber to new areas may be the most common way the plant spreads. The plant grows in disturbed habitat types, such as roadsides, often on wet soils. It grows in turf and in beds of ornamental plants.


The plant was considered to be a Florida endemic until the 1940s and 1950s, when it began to spread throughout the southeastern United States. Its rhizome system extends easily into the loose soils of cultivated ground, and it became a weed of residential and commercial land. It can be found in lawns and other turfgrass, especially centipedegrass and St. Augustine grass. It is a weed of ornamentals, where it can be harder to control than in lawns, because fewer herbicides are approved for use on ornamental herbs and shrubs than on turfgrasses. It is one of the worst weeds of the cultivated ornamental leatherleaf fern (Rumohra adiantiformis). Weed control in ornamentals may require hand-pulling, with careful removal of all the tubers.


Much like its relative, the Chinese artichoke, the "crisp, succulent" tuber is edible, and has "a pleasingly crunchy texture and a bland, slightly sweet taste".


Stachys palustris, commonly known as marsh woundwort, clown's woundwort, clown's heal-all, marsh hedgenettle, or hedge-nettle, is an edible perennial grassland herb growing to 80 centimeters tall.  It is native to parts of Eurasia but has been introduced to North America. The species epithet palustris is Latin for "of the marsh" and indicates its common habitat.


Marsh woundwort is a perennial plant growing from a horizontal tuberous runner. It has square stems with opposite pairs of leaves that are almost stalkless, linearly lanceolate, slightly cordate at the base and toothed. The calyx has five sharply-pointed lobes. The purplish-red flowers are in terminal spikes, with gaps in the lower part of the spike. They are arranged in whorls, each flower consisting of five fused petals, the corolla being two-lipped, the upper lip being gently hooded and the lower lip flat and three-lobed. The flowers are mostly visited by bumblebees. There are four stamens, two long and two short and the fruit is a dry four-chambered schizocarp.


The marsh woundwort is native to Europe and Asia. Its typical habitat is near the shore of lakes, in marshes with alder trees, on the banks of ditches and streams, in damp meadows, in arable ground and in waste places. In arable land, it is a difficult weed to get rid of because of its persistent tubers.


Although the marsh woundwort has little fragrance, it is very attractive to bumblebees. Nectar indicators guide the insect to probe into the centre of the flower and the anthers of the stamens and the pistils are correctly located for the insect to transfer pollen between flowers. The seeds of this plant disperse well, the dry fruit capsules float away and this probably why the plant is frequently found on the banks of lakes and other bodies of water. It also spreads vegetatively by means of hollow tuberous root which can throw up shoots far from the original plant.


As their common names suggest, along with its close relatives field woundwort and hedge woundwort it is used to promote the healing of wounds. Wort is a middle English word for a herb or vegetable.


Stachys recta, commonly known as stiff hedgenettle or perennial yellow-woundwort, is herbaceous perennial plant of the family Lamiaceae.


The biological form of S. recta is hemicryptophyte scapose, as its overwintering buds are situated just below the soil surface and the floral axis is more or less erect with a few leaves.
The plant reaches on average 20–40 centimetres (7.9–15.7 in) in height. It has thick, woody roots. The stems are strong, simple or branched, with slightly rough glandular hairs. The leaves are ovate-spatulate to oblong-lanceolate, with toothed edges and a long petiole. The length  of the leaves is  3–5 centimetres (1.2–2.0 in)  and the width 0.5 to 2 cm. 5–20 millimetres (0.20–0.79 in).
The flowers are gathered in a dense terminal spike and are usually yellowish-white, stained by purple or brown spots. The calyx is 5–10 centimetres (2.0–3.9 in) long. The flowering period extends from July through October. The flowers are hermaphrodite and pollinated by insects. The fruit are achenesabout 2 mm long, rounded, chestnut-brown and smooth or very finely punctured. This plant is strictly related to S. officinalis, and has similar properties and characteristics.


This plant is a sub-Mediterranean floral element and it is widespread from Europe to the Caucasus and Asia Minor.


Stachys recta grows in lawns, in semi-dry and dry grasslands and in rocky hillsides. It prefers calcareous and moderately dry soil, at an altitude of 0–2,100 metres (0–6,890 ft) above sea level.


Stachys sylvatica, commonly known as hedge woundwort, whitespot, or sometimes as hedge nettle, is a perennial herbaceous plant growing to 80 cm (31 in) tall in woodland and unmanaged grassland. In temperate zones of the northern hemisphere it flowers in July and August. The flowers are purple. The leaves, when crushed or bruised, give off an unpleasant fetid smell.


Hedge woundwort is an erect perennial plant with slender underground runners. The stem branches occasionally and is squarish and hairy, with glandular hairs on the upper part of the plant. The nodes are widely spaced, and the mid-green, stalked leaves are in opposite pairs. The leaf blades are hairy, have a cordate base and are ovate with a blunt tip and with regular large teeth on the margin. The inflorescence forms a dense terminal spike and is composed of dense whorls of purple flowers with white markings. The calyx has five lobes and the corolla forms a two-lipped flower about 12 to 18 mm (0.47 to 0.71 in) long with a fused tube. The upper lip of each flower is convex with dense, glandular hairs and the lower lip is three-lobed, the central lobe being the largest. There are four stamens, two long and two short, the gynoecium has two fused carpels and the fruit is a four-chambered schizocarp. The plant has a slightly unpleasant smell.


Hedge woundwort is native to Europe and central and western Asia. It grows in dappled shade at the edge of woods, in hedgerows and on rough ground. It has been introduced into New York state, Ontario, and New Zealand.


Hedge woundwort is popular with bees. Along with its close relatives field woundwort and marsh woundwort, as their common names suggest, they are used to promote the healing of wounds. The famous 17th century herbalist John Gerard was very impressed with its powers and used it extensively.


The fresh leaves are consumed in bush tea as a “cooling” tonic and blood cleanser, to treat “asthma” and “ulcerated stomachs”.
Tea brewed from this species has been shown to cause a dose-dependent "fall in [the] blood pressure" of normal rabbits. However, the tea has also been observed to cause a "mild non-dose dependent systematic toxicity" in various tissues throughout the body, "such as congestion, fatty changes, and necrosis in liver, blood vessels, kidney, lung and testis, but the brain, eyes, intestines and heart were essentially normal."


The Carolina mantis (Stagmomantis carolina) is a species of praying mantis of the subfamily Stagmomantinae.
Sexual cannibalism occurs in roughly one quarter of all intersexual encounters of this species, though specimens of this species will engage in cannibalism regardless of age or gender if the opportunity presents itself.
The Carolina mantis is the state insect of South Carolina. Oothecae can be purchased in garden supply centers as a means of biological control of pest insects. However, only those labeled as this species should be released because most oothecae sold in the United States belong to the invasive Chinese mantis.


Adult females are 47 to 60 millimeters (2-2.5 inches) in length while adult males are usually about 54 millimeters (2.2 inches) in length. First instar nymphs are 7-12 millimeters (.028-.047 inches) in length. When the nymphs eat more, their abdomens get much longer. The Carolina mantis has a dusty brown, gray or green color useful as camouflage in certain environments. The Carolina mantis' color varies because the nymphs are able to adjust their color to match the environment they are in at the time of molting. They can adjust their color over each molt, if necessary, until they reach their final molt to adulthood. An unusual trait is that its wings only extend three-quarters of the way down the abdomen in mature females; this trait is also seen in Iris oratoria, which can be distinguished by the large eyespots on the hind wings (inner wings) of both adult male and female Iris oratoria. Both adult male and female Stagmomantis carolina have a dark-coloured dot on each of their forewings (outer wings), which may be partially hidden in a brown or dark colour morph individual.


Stagmomantis carolina is native to the Americas and can be found from the United States southwards to Brazil.


Stanleya pinnata is a species of flowering plant in the family Brassicaceae known as desert princesplume. It is a perennial herb or shrub native to North America.


The plant is native to the western Great Plains and western North America.
It occurs in many types of open habitat, including deserts, chaparral, foothills, rocky cliffs, sagebrush, and prairie. It prefers alkali- and gypsum-rich soils.


Stanleya pinnata is a perennial herb or shrub producing several erect stems reaching up to about 1.5 metres (4+11⁄12 ft) in maximum height. The stems are unbranched, hairless, often waxy in texture, and have woody bases. The leaves have fleshy blades up to 15 centimeters long by 5 wide which are divided into several long, narrow lobes. The blades are borne on petioles.
The top of the stem is occupied by a long inflorescence which is a dense raceme of many flowers. Each flower has four narrow yellowish sepals which open to reveal four bright yellow petals each up to 2 cm long. The stamens protruding from the flower's center may approach 3 cm in length.
The fruit is a curving, wormlike silique up to 8 cm long.


It has been used as a Native American traditional medicinal plant and food source, including by the Hopi, Zuni, Paiute, Navajo, Kawaiisu, and Tewa peoples.


It is a larval host to both Becker's white and checkered white caterpillars.
Some of the plant's amino acids use selenium from the soil in place of sulfur, making it highly toxic to animals.


Staphylea trifolia, the American bladdernut, is native to eastern North America, from southern Ontario and southwestern Quebec west to Nebraska and Arkansas, and south to Florida. It is sometimes used as an ornamental plant.
It is a medium-sized shrub growing to 3.5 m (11 ft) tall. Its growth rate is medium to fast. The leaves are opposite and divided into three leaflets, each leaflet 4.5–13 cm (2–5 in) long and 5 cm (2 in) broad, with a serrated margin. The leaves are bright green in the spring, turning dark green in the summer. S. trifolia produces pendant white flowers in spring, which mature into bladder-like, teardrop-shaped fruits that contain 1-3 brown popcorn-like seeds. Some sources consider these "nuts" to be edible.


Stegasta bosqueella (red-necked peanutworm moth) is a species of moth of the family Gelechiidae. It is found in North America, including Alabama, Florida, Georgia, Illinois, Iowa, North Carolina, Oklahoma, South Carolina, Texas and Virginia.
The larvae are a pest on Arachis hypogaea. They feed on the foliage of their host plant.


The southern rough-winged swallow (Stelgidopteryx ruficollis) is a small swallow. It was first formally described as Hirundo ruficollis by French ornithologist Louis Vieillot in 1817 in his Nouveau Dictionnaire d'Histoire Naturelle.


It is found in open areas and forest clearings. It nests in grass-lined cavities of various types, including holes in banks or walls, or disused kingfisher and jacamar nests. It does not form colonies. The clutch is 3–6 white eggs, incubated by the female for 16–18 days and with another 13 days to fledging. Southern rough-winged swallows forage for insects (such as plant bugs, beetles, flies, flying ants and heteropterans) in flight, usually flying low with a slow deliberate flight. The call is an unmusical chirrup.


The northern rough-winged swallow (Stelgidopteryx serripennis) is a small, migratory swallow. It is very similar to the southern rough-winged swallow, Stelgidopteryx ruficollis.


The genus name, Stelgidopteryx, is from Ancient Greek and means "scraper wing" and the species name, serripennis, is derived from Latin and means "saw feather". In the common name, "rough-winged" refers to the serrated edge feathers on the wing of this bird; this feature would only be apparent when holding this bird.


Six subspecies of the northern rough-winged swallow are currently recognized.
S. s. serripennis is the nominate subspecies and can be found to occur in southern Alaska and Canada to the southern United States. They are found to usually winter in southern Florida and from southwestern Mexico to Panama. It was described by Audubon in 1838.
S. s. psammochroa was described by Ludlow Griscom in 1929. It breeds in the southwestern US and winters from central Mexico to Panama. It can be differentiated from the nominate race by being paler, especially on the crown and rump.
S. s. fulvipennis is a resident of central Mexico to Costa Rica. It was the first subspecies to be differentiated from the nominate race, serripennis, and was differentiated by Philip Sclater in 1860. It is darker above; the crown darker more so. The shafts of the undertail coverts, the feathers under the tail, covering the base, have been observed to be darker near the end. The throat of these swallows seems to be slightly buff, unlike most of the other subspecies.
S. s. stuarti, a very dark variant of the northern rough-winged swallow, was described by Pierce Brodkorb in 1942. It is resident to the southern Mexico lowlands and south to eastern Guatemala. Like the race fulvipennis, it has a slightly buff throat. The undertail coverts also have black tips.
S. s. ridgwayi, described by Edward Nelson in 1901, is a subspecies resident to the northern Yucatán Peninsula. It is larger than the nominate race with a whitish spot above its lores and has blackish tips on the longest of its undertail coverts. In addition, it is darker above and has paler anterior underparts.
S. s. burleighi, described by Allan Robert Phillips in 1986, is the most recent, widely accepted subspecies. It is resident to Belize and Guatemala, and is the darkest of the subspecies.
It has been proposed that another race aphracta be recognized, but this is debated. This race is apparently described as being darker above with a greyer throat compared to serripennis. It has been described as occurring in the western Great Basin region, in the United States.


Adults are 13–15 cm (5.1–5.9 in) in length, brown above with white underparts, a small bill, and a forked tail. Their throat is white with a brownish-grey wash, and below the throat are white underparts. The adults have a wingspan of 27–30 cm (11–12 in) and a weight of 10–18 g (0.35–0.63 oz). The males' undertail coverts are longer and broader than those of the females. The males also have hooked barbs on the outer web of their outer primary wings. The barbs on the females are shorter and straighter than those of the males. Juveniles can be distinguished from adults by their reddish-brown wing-bars.
They are similar in appearance to the bank swallow, but have a dusky throat and breast. They are closely related and very similar to the southern rough-winged swallow, Stelgidopteryx ruficollis, but that species has a more contrasting rump, and the ranges do not quite overlap.


The call of this swallow is described as a short, harsh zeep. It has also been described as a rough, low bzzt. It is often doubled. This call is similar to the call of the bank swallow.


The northern rough-winged swallow is native to Bahamas, Belize, Canada, Cayman Islands, Costa Rica, Cuba, El Salvador, Guatemala, Haiti, Honduras, Jamaica, Mexico, Nicaragua, Panama, Puerto Rico, Saint Pierre and Miquelon, Turks and Caicos Islands, and the United States. They are vagrant to Aruba, Barbados, Bonaire, Sint Eustatius and Saba, Curaçao, Dominican Republic, Guadeloupe, and Sint Maarten. The populations in the US and Canada have been found to winter in the southernmost US and further south. While this is true, the populations in Mexico and further south seem to be non-migratory, although local post-breeding movements do occur. This swallow has been found to occur as high as 2,500 m (8,200 ft) in Costa Rica.


The northern rough-winged swallow usually nests by itself, although sometimes it is found in loose groups, often at the edge of bank swallow colonies, of up to 25 pairs. The nests are found in burrows located in soil banks, very occasionally caves and trees, and in human-made cavities such as gutters and tubes. These burrows are usually built by other species, and measure anywhere from 20 to 200 cm (7.9 to 78.7 in) in length, although most fall between 30 and 100 cm (11.8 and 39.4 in). They are at a height of around 0.2 to 30 m (0.7 to 98.4 ft) above ground-level. The nest itself is built by this species, and made with a variety of fibres, including grasses, leaves, rootlets, twigs, bark, and pine needles. Moss and dung are also used. The nest is then lined with grass. These materials are wholly or almost wholly collected by the female.
The breeding season generally extends from May to about mid-July, but this varies by region. In north-eastern North America, the breeding season starts about mid-May, while it starts in early June in the north-west, with both ending in August. In the southern parts of its range, this bird lays its eggs earlier; for example, from mid-April to mid-May in Costa Rica.
The northern rough-winged swallow lays a single clutch, although sometimes another clutch is laid if the first one fails, of four to eight glossy white eggs that measure about 20 by 14 mm (0.79 by 0.55 in) on average. It has been observed that the clutch size decreases with decreasing latitude. These eggs are incubated by the female for 16 to 18 days. Because the female starts incubating as soon as the first egg is laid, the eggs hatch asynchronously.


The northern rough-winged swallow migrates to the Gulf Coast of the United States and south to Central America for winter. They have also been recorded to winter in the Caribbean.
When the breeding season is finished, they usually form large flocks and roost together in marshes and similar environments. Sometimes, in adverse weather conditions, several of these swallows can be seen to share a burrow.


When foraging, their flight paths are low and direct. They fly with slow, deep wingbeats interspersed with periods of gliding. They usually feed over water and occasionally over land. They are insectivores, feeding almost exclusively on flying insects. Although this is true, there is a report of some feeding on cracked corn. To drink, they skim the surface of the water with their wing and then drink on their wing.


The northern rough-winged swallow is classified as least concern by the IUCN. Although its population is declining, it is not declining fast enough nor is its range small enough to justify a classification of vulnerable. In addition, this species is estimated to be composed of about 15 million individual birds, so it is not vulnerable under the population size criterion. This swallow has been found to adapt well to humans and sometimes nests in artificial cavities created by them.


Stellaria graminea is a species of flowering plant in the family Caryophyllaceae known by the common names common starwort, grass-leaved stitchwort, lesser stitchwort and grass-like starwort.


It is a rhizomatous perennial herb producing branching stems which are prostrate, sprawling, trailing, or erect, and reach up to about 90 centimeters long. The stems are four-angled, weak, and hairless. It is lined with pairs of linear or lance-shaped leaves, each 1–4 centimetres (0.4–1.6 in) long. The leaves are smooth-edged and hairless except for some hairs lining the bases. The inflorescence bears several flowers, each on a short pedicel. The flower has five pointed green sepals each a few millimeters long which are usually lined with hairs. There are five white petals, each so deeply lobed it appears to be two. The seeds are reddish brown in colour and are 1 millimetre (0.04 in) in diameter. It bears 10 stamens.


It is native to Eurasia but it is widespread around other parts of the temperate world as an introduced species and a common weed.


It grows in many types of habitat, including lawns and roadsides.


Stellaria nemorum, also known by the common name wood stitchwort, is a stoloniferous herbaceous perennial flowering plant in  the family Caryophyllaceae.


It reaches a height of 60 cm and blooms from May to August. The leaves are opposite, the upper leaves sessile and the lower leaves petiolate. The flowers are white, with 5 deeply bifid petals, 10 stamens and 3 styles.


It is native to Europe and thrives in wet places of deciduous forests, such as beech forests.


Stenocereus gummosus is a  flowering plant in the family Cactaceae that is found in Baja California, Mexico at elevations of 9 to 134 meters


Stenotus binotatus is a fairly large plant bug (6–7 millimetres or 0.24–0.28 inches long), which is somewhat variable in appearance. The insect's sides are roughly parallel, and the colours depend on both the animal's sex and its age, the markings becoming darker and stronger with increasing age. Males are mostly yellow, with darker markings on the pronotum and forewings, which females are greenish-yellow with paler markings.


S. binotatus is native to most of the Palearctic but has been introduced to temperate regions around the world. It is common "throughout the northern and central U.S. and southern Canada", and it has been introduced to New Zealand, where it now found almost throughout the country.


Both the nymphs and adults feed on the inflorescences of grasses, especially timothy-grass (Phleum pratense). In New Zealand, S. binotatus has been collected from a large variety of plants, including the grasses brown top, Yorkshire fog, cocksfoot, wheat, barley and maize, and many other plants (including rushes, Hypericum, Leptospermum scoparium, Metrosideros, Nothofagus, Coriaria, Olearia, Muehlenbeckia, Carmichaelia, Larix decidua, Eucalyptus, Melicytus ramiflorus, Coprosma robusta, hemlock and nettles).
Adults are active from June to September in the United Kingdom, and in December and January in New Zealand.


Stenotus binotatus produces an enzyme which degrades the gluten in the grasses it feeds on. These enzymes are believed to be responsible for the characteristic "sticky dough" produced from wheat which has been attacked by plant bugs such as S. binotatus.
The wheat grain does not show a pale area or puncture mark after attack by S. binotatus, in contrast to other bugs. Instead, the grains appear collapsed. Wheat grains from known bug infestation in New Zealand do not resemble those produced by S. binotatus, and SDS-PAGE patterns also suggest that S. binotatus was not the cause of infestations.


Stenotus binotatus was originally described under the name Lygaeus binotatus by Johan Christian Fabricius in 1794. The genus Stenotus was erected by Wassily Ewgrafowitsch Jakowlew (also transcribed as "Jakovlev") in 1877, and S. binotatus was designated its type species.
S. binotatus is known by various common names, including two-spotted plant bug, timothy plant bug, and slender crop mirid.


This beetle is widespread in most of Europe, in the eastern Palearctic realm, in the Oriental realm, and in the Near East.
It is present in Portugal, Spain, France, Belgium, the Netherlands, Switzerland, Italy, Germany, Austria, Great Britain, Denmark, Sweden, Norway, Finland, Poland, Czech Republic, Slovakia, Hungary, Slovenia, Croatia, Serbia, Albania, Romania, Bulgaria, Greece, Turkey, Russia, Kazakhstan and Mongolia.


These beetles inhabit sunny forest edges, mixed coniferous forests, spruce pine forests and alpine and mountain pastures.


Stenurella melanura can reach a length of 6–10 millimetres (0.24–0.39 in). This beetle has a very narrow and rather long body. The antennae are about as long as the body. The head, pronotum and abdomen are black. The elytra are yellow-brown in males, with a black colored tip. In the females the elytra are reddish. The elytral suture is often black-colored, especially in the females, while the slender males have a darker tip and the black drawing is somewhat less pronounced.


Both females and males can mate several times, and the males often remain on the female to prevent her from interacting with other males. Larvae develop in rotten wood of deciduous and coniferous trees, especially Castanea sativa. Adults can be encountered from May through September, completing their life cycle in two years. They are very common flower-visitors, especially Apiaceae species, feeding on pollen and the nectar.


Stephanomeria pauciflora is a species of flowering plant in the aster family known by the common names brownplume wirelettuce, few-flowered wirelettuce, and prairie skeletonplant. It is native to the southwestern United States and northern Mexico, where it grows in many types of habitat, including many desert areas, woodlands, and plains. It is a perennial herb or bushy subshrub producing one or more sturdy, stiff stems with many spreading branches, taking a rounded but vertical form. The leaves are mostly basal and ephemeral, with smaller, scale-like leaves occurring on the upper stem. Flower heads occur at intervals along the mostly naked stems, especially near the tips. Each has a cylindrical base covered in hairless phyllaries. It contains 3 to 6 florets, each with an elongated tube and a flat pink ligule. The fruit is an achene tipped with a spreading cluster of plumelike pappus bristles. These are usually brownish, but are sometimes white.
The specific epithet pauciflora, refers to the Latin term for 'few flowered'.


The common tern (Sterna hirundo) is a seabird in the family Laridae. This bird has a circumpolar distribution, its four subspecies breeding in temperate and subarctic regions of Europe, Asia and North America. It is strongly migratory, wintering in coastal tropical and subtropical regions. Breeding adults have light grey upperparts, white to very light grey underparts, a black cap, orange-red legs, and a narrow pointed bill. Depending on the subspecies, the bill may be mostly red with a black tip or all black. There are several similar species, including the partly sympatric Arctic tern, which can be separated on plumage details, leg and bill colour, or vocalisations.
Breeding in a wider range of habitats than any of its relatives, the common tern nests on any flat, poorly vegetated surface close to water, including beaches and islands, and it readily adapts to artificial substrates such as floating rafts. The nest may be a bare scrape in sand or gravel, but it is often lined or edged with whatever debris is available. Up to three eggs may be laid, their dull colours and blotchy patterns providing camouflage on the open beach. Incubation is by both sexes, and the eggs hatch in around 21–22 days, longer if the colony is disturbed by predators. The downy chicks fledge in 22–28 days. Like most terns, this species feeds by plunge-diving for fish, either in the sea or in freshwater, but molluscs, crustaceans and other invertebrate prey may form a significant part of the diet in some areas.
Eggs and young are vulnerable to predation by mammals such as rats and American mink, and large birds including gulls, owls and herons. Common terns may be infected by lice, parasitic worms, and mites, although blood parasites appear to be rare. Its large population and huge breeding range mean that this species is classed as being of least concern, although numbers in North America have declined sharply in recent decades. Despite international legislation protecting the common tern, in some areas, populations are threatened by habitat loss, pollution, or the disturbance of breeding colonies.


Terns are small to medium-sized seabirds closely related to the gulls, skimmers and skuas. They are gull-like in appearance, but typically have a lighter build, long pointed wings (which give them a fast, buoyant flight), a deeply forked tail, slender legs, and webbed feet. Most species are grey above and white below, and have a black cap which is reduced or flecked with white in the non-breeding season.
The common tern's closest relatives appear to be the Antarctic tern, followed by the Eurasian Arctic and roseate terns. Genetic evidence suggests that the common tern may have diverged from an ancestral stock earlier than its relatives. No fossils are known from North America, and those claimed in Europe are of uncertain age and species.
The common tern was first described by Carl Linnaeus in his landmark 1758 10th edition of Systema Naturae under its current scientific name, Sterna hirundo. "Stearn" was used in Old English, and a similar word was used by the Frisians for the birds. "Stearn" appears in the poem The Seafarer, written around 1000 A.D. Linnaeus adopted this word for the genus name Sterna. The Latin for swallow is hirundo, and refers here to the tern's superficial likeness to that unrelated bird, which has a similar light build and long forked tail. This resemblance also leads to the informal name "sea swallow", recorded from at least the seventeenth century. The Scots names picktarnie, tarrock and their many variants are also believed to be onomatopoeic, derived from the distinctive call. Because of the difficulty in distinguishing the two species, all the informal common names are shared with the Arctic tern. The there was some uncertainty whether Sterna hirundo should apply to the common tern or the arctic tern as the species are very similar and both occur in Sweden. In 1913, the Swedish zoologist Einar Lönnberg concluded that the binomial name Sterna hirundo applied to the common tern.
Four subspecies of the common tern are generally recognized, although S. h. minussensis is sometimes considered an intergrade between S. h. hirundo and S. h. longipennis.


The nominate subspecies of the common tern is 31–35 cm (12–14 in) long, including a 6–9 cm (2.4–3.5 in) fork in the tail, with a 77–98 cm (30–39 in) wingspan. It weighs 110–141 g (3.9–5.0 oz). Breeding adults have pale grey upperparts, very pale grey underparts, a black cap, orange-red legs, and a narrow pointed bill that can be mostly red with a black tip, or all black, depending on the subspecies. The common tern's upper wings are pale grey, but as the summer wears on, the dark feather shafts of the outer flight feathers become exposed, and a grey wedge appears on the wings. The rump and tail are white, and on a standing bird the long tail extends no further than the folded wingtips, unlike the Arctic and roseate terns in which the tail protrudes beyond the wings. There are no significant differences between the sexes. In non-breeding adults, the forehead and underparts become white, the bill is all black or black with a red base, and the legs are dark red or black. The upper wings have an obvious dark area at the front edge of the wing, the carpal bar. Terns that have not bred successfully may moult into non-breeding adult plumage beginning in June, though late July is more typical, with the moult suspended during migration. There is also some geographical variation; Californian birds are often in non-breeding plumage during migration.
Juvenile common terns have pale grey upper wings with a dark carpal bar. The crown and nape are brown, and the forehead is ginger, wearing to white by autumn. The upper parts are ginger with brown and white scaling, and the tail lacks the adult's long outer feathers. Birds in their first post-juvenile plumage, which normally remain in their wintering areas, resemble the non-breeding adult, but have a duskier crown, dark carpal bar, and often very worn plumage. By their second year, most young terns are either indistinguishable from adults, or show only minor differences such as a darker bill or white forehead.
The common tern is an agile flyer, capable of rapid turns and swoops, hovering, and vertical take-off. When commuting with fish, it flies close to the surface in a strong head wind, but 10–30 m (33–98 ft) above the water in a following wind. Unless migrating, normally it stays below 100 m (330 ft), and averages 30 km/h (19 mph) in the absence of a tail wind. Its average flight speed during the nocturnal migration flight is 43–54 km/h (27–34 mph) at a height of 1,000–3,000 m (3,300–9,800 ft).


There are several terns of a similar size and general appearance to the common tern. A traditionally difficult species to separate is the Arctic tern, and until the key characteristics were clarified, distant or flying birds of the two species were often jointly recorded as "commic terns". Although similar in size, the two terns differ in structure and flight. The common tern has a larger head, thicker neck, longer legs, and more triangular and stiffer wings than its relative, and has a more powerful, direct flight. Arctic terns have greyer underparts than the common variety, which makes its white cheeks more obvious, whereas the rump of the common tern can be greyish in non-breeding plumage, compared to the white of its relative. The common tern develops a dark wedge on the wings as the breeding season progresses, but the wings of the Arctic stay white throughout the northern summer. All the flight feathers of the Arctic tern are translucent against a bright sky, only the four innermost wing feathers of the common tern share this property. The trailing edge of the outer flight feathers is a thin black line in the Arctic tern, but thicker and less defined in the common. The bill of an adult common tern is orange-red with a black tip, except in black-billed S. h. longipennis, and its legs are bright red, while both features are a darker red colour in the Arctic tern, which also lacks the black bill tip.
In the breeding areas, the roseate tern can be distinguished by its pale plumage, long, mainly black bill and very long tail feathers. The non-breeding plumage of roseate is pale above and white, sometimes pink-tinged, below. It retains the long tail streamers, and has a black bill. In flight, the roseate's heavier head and neck, long bill and faster, stiffer wingbeats are also characteristic. It feeds further out to sea than the common tern. In North America, the Forster's tern in breeding plumage is obviously larger than the common, with relatively short wings, a heavy head and thick bill, and long, strong legs; in all non-breeding plumages, its white head and dark eye patch make the American species unmistakable.
In the wintering regions, there are also confusion species, including the Antarctic tern of the southern oceans, the South American tern, the Australasian white-fronted tern and the white-cheeked tern of the Indian Ocean. The plumage differences due to "opposite" breeding seasons may aid in identification. The Antarctic tern is more sturdy than the common, with a heavier bill. In breeding condition, its dusky underparts and full black cap outline a white cheek stripe. In non-breeding plumages, it lacks, or has only an indistinct, carpal bar, and young birds show dark bars on the tertials, obvious on the closed wing and in flight. The South American tern is larger than the common, with a larger, more curved red bill, and has a smoother, more extensive black cap in non-breeding plumage. Like Antarctic, it lacks a strong carpal bar in non-breeding plumages, and it also shares the distinctive barring of the tertials in young birds. The white-fronted tern has a white forehead in breeding plumage, a heavier bill, and in non-breeding plumage is paler below than the common, with white underwings. The white-cheeked tern is smaller, has uniform grey upperparts, and in breeding plumage is darker above with whiter cheeks.
Juvenile common terns are easily separated from similar-aged birds of related species. They show extensive ginger colouration to the back, and have a pale base to the bill. Young Arctic terns have a grey back and black bill, and juvenile roseate terns have a distinctive scalloped "saddle". Hybrids between common and roseate terns have been recorded, particularly from the US, and the intermediate plumage and calls shown by these birds is a potential identification pitfall. Such birds may have more extensive black on the bill, but confirmation of mixed breeding may depend on the exact details of individual flight feathers.


Common terns have a wide repertoire of calls, which have a lower pitch than the equivalent calls of Arctic terns. The most distinctive sound is the alarm KEE-yah, stressed on the first syllable, in contrast to the second-syllable stress of the Arctic tern. The alarm call doubles up as a warning to intruders, although serious threats evoke a kyar, given as a tern takes flight, and quietens the usually noisy colony while its residents assess the danger. A down-slurred keeur is given when an adult is approaching the nest while carrying a fish, and is possibly used for individual recognition (chicks emerge from hiding when they hear their parents giving this call). Another common call is a kip uttered during social contact. Other vocalizations include a kakakakaka when attacking intruders, and a staccato kek-kek-kek from fighting males.
Parents and chicks can locate one another by call, and siblings also recognise each other's vocalisations from about the twelfth day from hatching, which helps to keep the brood together.


Most populations of the common tern are strongly migratory, wintering south of their temperate and subarctic Northern Hemisphere breeding ranges. First summer birds usually remain in their wintering quarters, although a few return to breeding colonies some time after the arrival of the adults. In North America, the common tern breeds along the Atlantic coast from Labrador to North Carolina, and inland throughout much of Canada east of the Rocky Mountains. In the United States, some breeding populations can also be found in the states bordering the Great Lakes, and locally on the Gulf coast. There are small, only partially migratory, colonies in the Caribbean; these are in The Bahamas and Cuba, and off Venezuela in the Los Roques and Las Aves archipelagos.
New World birds winter along both coasts of Central and South America, to Argentina on the east coast and to northern Chile on the west coast. Records from South America and the Azores show that some birds may cross the Atlantic in both directions on their migration.
The common tern breeds across most of Europe, with the highest numbers in the north and east of the continent. There are small populations on the north African coast, and in the Azores, Canary Islands and Madeira. Most winter off western or southern Africa, birds from the south and west of Europe tending to stay north of the equator and other European birds moving further south. The breeding range continues across the temperate and taiga zones of Asia, with scattered outposts on the Persian Gulf and the coast of Iran. Small populations breed on islands off Sri Lanka, and in the Ladakh region of the Tibetan plateau. Western Asian birds winter in the northern Indian Ocean, and S. h. tibetana appears to be common off East Africa during the Northern Hemisphere winter. Birds from further north and east in Asia, such as S. h. longipennis, move through Japan, Thailand and the western Pacific as far as southern Australia. There are small and erratic colonies in West Africa, in Nigeria and Guinea-Bissau, unusual in that they are within what is mainly a wintering area. Only a few common terns have been recorded in New Zealand, and this species' status in Polynesia is unclear. A bird ringed at the nest in Sweden was found dead on Stewart Island, New Zealand, five months later, having flown an estimated 25,000 km (15,000 mi).
As long-distance migrants, common terns sometimes occur well outside their normal range. Stray birds have been found inland in Africa (Zambia and Malawi), and on the Maldives and Comoros islands; the nominate subspecies has reached Australia, the Andes, and the interior of South America. Asian S. h. longipennis has recent records from western Europe.
The common tern breeds over a wider range of habitats than any of its relatives, nesting from the taiga of Asia to tropical shores, and at altitudes up to 2,000 m (6,600 ft) in Armenia, and 4,800 m (15,700 ft) in Asia. It avoids areas which are frequently exposed to excessive rain or wind, and also icy waters, so it does not breed as far north as the Arctic tern. The common tern breeds close to freshwater or the sea on almost any open flat habitat, including sand or shingle beaches, firm dune areas, salt marsh, or, most commonly, islands. Flat grassland or heath, or even large flat rocks may be suitable in an island environment. In mixed colonies, common terns will tolerate somewhat longer ground vegetation than Arctic terns, but avoid the even taller growth acceptable to roseate terns; the relevant factor here is the different leg lengths of the three species. Common terns adapt readily to artificial floating rafts, and may even nest on flat factory roofs. Unusual nest sites include hay bales, a stump 0.6 m (2 ft) above the water, and floating logs or vegetation. There is a record of a common tern taking over a spotted sandpiper nest and laying its eggs with those of the wader. Outside the breeding season, all that is needed in terms of habitat is access to fishing areas, and somewhere to land. In addition to natural beaches and rocks, boats, buoys and piers are often used both as perches and as night-time roosts.


The common tern breeds in colonies which do not normally exceed two thousand pairs, but may occasionally number more than twenty thousand pairs. Colonies inland tend to be smaller than on the coast. Common terns often nest alongside other coastal species, such as Arctic, roseate and Sandwich terns, black-headed gulls, and black skimmers. Especially in the early part of the breeding season, for no known reason, most or all of the terns will fly in silence low and fast out to sea. This phenomenon is called a "dread".
On their return to the breeding sites, the terns may loiter for a few days before settling into a territory, and the actual start of nesting may be linked to a high availability of fish. Terns defend only a small area, with distances between nests sometimes being as little as 50 cm (20 in), although 150–350 cm (59–138 in) is more typical. As with many birds, the same site is re-used year after year, with a record of one pair returning for 17 successive breeding seasons. Around ninety per cent of experienced birds reuse their former territory, so young birds must nest on the periphery, find a bereaved mate, or move to another colony. A male selects a nesting territory a few days after his arrival in the spring, and is joined by his previous partner unless she is more than five days late, in which case the pair may separate.
The defence of the territory is mainly by the male, who repels intruders of either sex. He gives an alarm call, opens his wings, raises his tail and bows his head to show the black cap. If the intruder persists, the male stops calling and fights by bill grappling until the intruder submits by raising its head to expose the throat. Aerial trespassers are simply attacked, sometimes following a joint upward spiralling flight. Despite the aggression shown to adults, wandering chicks are usually tolerated, whereas in a gull colony they would be attacked and killed. The nest is defended until the chicks have fledged, and all the adults in the colony will collectively repel potential predators.


Pairs are established or confirmed through aerial courtship displays in which a male and a female fly in wide circles up to 200 m (660 ft) or more, calling all the while, before the two birds descend together in zigzag glides. If the male is carrying a fish, he may attract the attention of other males too. On the ground, the male courts the female by circling her with his tail and neck raised, head pointing down, and wings partially open. If she responds, they may both adopt a posture with the head pointed skywards. The male may tease a female with the fish, not parting with his offering until she has displayed to him sufficiently. Once courtship is complete, the male makes a shallow depression in the sand, and the female scratches in the same place. Several trials may take place until the pair settle on a site for the actual nest. The eggs may be laid on bare sand, gravel or soil, but a lining of debris or vegetation is often added if available, or the nest may be rimmed with seaweed, stones or shells. The saucer-shaped scrape is typically 4 cm (1.6 in) deep and 10 cm (3.9 in) across, but may extend to as much as 24 cm (9.4 in) wide including the surrounding decorative material. Breeding success in areas prone to flooding has been enhanced by the provision of artificial mats made from eelgrass, which encourage the terns to nest in higher, less vulnerable areas, since many prefer the mats to bare sand. The common tern tends to use more nest material than roseate or Arctic terns, although roseate often nests in areas with more growing vegetation.
Terns are expert at locating their nests in a large colony. Studies show that terns can find and excavate their eggs when they are buried, even if the nest material is removed and the sand smoothed over. They will find a nest placed 5 m (16 ft) from its original site, or even further if it is moved in several stages. Eggs are accepted if reshaped with plasticine or coloured yellow (but not red or blue). This ability to locate the eggs is an adaptation to life in an unstable, wind-blown and tidal environment.
The peak time for egg production is early May, with some birds, particularly first-time breeders, laying later in the month or in June. The clutch size is normally three eggs; larger clutches probably result from two females laying in the same nest. Egg size averages 41 mm × 31 mm (1.6 in × 1.2 in), although each successive egg in a clutch is slightly smaller than the first laid. The average egg weight is 20.2 g (0.71 oz), of which five per cent is shell. The egg weight depends on how well-fed the female is, as well as on its position in the clutch. The eggs are cream, buff, or pale brown, marked with streaks, spots or blotches of black, brown or grey which help to camouflage them. Incubation is by both sexes, although more often by the female, and lasts 21–22 days, extending to 25 days if there are frequent disturbances at the colony which cause the adults to leave the eggs unattended; nocturnal predation may lead to incubation taking up to 34 days. On hot days the incubating parent may fly to water to wet its belly feathers before returning to the eggs, thus affording the eggs some cooling. Except when the colony suffers disaster, ninety per cent of the eggs hatch. The precocial downy chick is yellowish with black or brown markings, and like the eggs, is similar to the equivalent stage of the Arctic tern. The chicks fledge in 22–28 days, usually 25–26. Fledged juveniles are fed at the nest for about five days, and then accompany the adults on fishing expeditions. The young birds may receive supplementary feeds from the parents until the end of the breeding season, and beyond. Common terns have been recorded feeding their offspring on migration and in the wintering grounds, at least until the adults move further south in about December.
Like many terns, this species is very defensive of its nest and young, and will harass humans, dogs, muskrats and most diurnal birds, but unlike the more aggressive Arctic tern, it rarely hits the intruder, usually swerving off at the last moment. Adults can discriminate between individual humans, attacking familiar people more intensely than strangers. Nocturnal predators do not elicit similar attacks; colonies can be wiped out by rats, and adults desert the colony for up to eight hours when great horned owls are present.
Common terns usually breed once a year. Second clutches are possible if the first is lost. Rarely, a second clutch may be laid and incubated while some chicks from the first clutch are still being fed. The first breeding attempt is usually at four years of age, sometimes at three years. The average number of young per pair surviving to fledging can vary from zero in the event of the colony being flooded to over 2.5 in a good year. In North America, productivity was between 1.0 and 2.0 on islands, but less than 1.0 at coastal and inland sites. Birds become more successful at raising chicks with age. This continues throughout their breeding lives, but the biggest increase is in the first five years. The maximum documented lifespan in the wild is 23 years in North America and 33 years in Europe, but twelve years is a more typical lifespan.


Like all Sterna terns, the common tern feeds by plunge-diving for fish, from a height of 1–6 m (3.3–19.7 ft), either in the sea or in freshwater lakes and large rivers. The bird may submerge for a second or so, but to no more than 50 cm (20 in) below the surface. When seeking fish, this tern flies head-down and with its bill held vertically. It may circle or hover before diving, and then plunges directly into the water, whereas the Arctic tern favours a "stepped-hover" technique, and the roseate tern dives at speed from a greater height, and submerges for longer. The common tern typically forages up to 5–10 km (3.1–6.2 mi) away from the breeding colony, sometimes as far as 15 km (9.3 mi). It will follow schools of fish, and its west African migration route is affected by the location of huge shoals of sardines off the coast of Ghana; it will also track groups of predatory fish or dolphins, waiting for their prey to be driven to the sea's surface. Terns often feed in flocks, especially if food is plentiful, and the fishing success rate in a flock is typically about one-third higher than for individuals.
Terns have red oil droplets in the cone cells of the retinas of their eyes. This improves contrast and sharpens distance vision, especially in hazy conditions. Birds that have to see through an air/water interface, such as terns and gulls, have more strongly coloured carotenoid pigments in the cone oil drops than other avian species. The improved eyesight helps terns to locate shoals of fish, although it is uncertain whether they are sighting the phytoplankton on which the fish feed, or observing other terns diving for food. Tern's eyes are not particularly ultraviolet sensitive, an adaptation more suited to terrestrial feeders like the gulls.
The common tern preferentially hunts fish 5–15 cm (2.0–5.9 in) long. The species caught depend on what is available, but if there is a choice, terns feeding several chicks will take larger prey than those with smaller broods. The proportion of fish fed to chicks may be as high as ninety-five per cent in some areas, but invertebrate prey may form a significant part of the diet elsewhere. This may include worms, leeches, molluscs such as small squid, and crustaceans (prawns, shrimp and mole crabs). In freshwater areas, large insects may be caught, such as beetles, cockchafers and moths. Adult insects may be caught in the air, and larvae picked from the ground or from the water surface. Prey is caught in the bill and either swallowed head-first, or carried back to the chicks. Occasionally, two or more small fish may be carried simultaneously. When adults take food back to the nest, they recognise their young by call, rather than visual identification.
The common tern may attempt to steal fish from Arctic terns, but might itself be harassed by kleptoparasitic skuas, laughing gulls, roseate terns, or by other common terns while bringing fish back to its nest. In one study, two males whose mates had died spent much time stealing food from neighbouring broods.
Terns normally drink in flight, usually taking seawater in preference to freshwater, if both are available. Chicks do not drink before fledging, reabsorbing water, and, like adults, excreting excess salt in a concentrated solution from a specialised nasal gland. Fish bones and the hard exoskeletons of crustaceans or insects are regurgitated as pellets. Adults fly off the nest to defecate, and even small chicks walk a short distance from the scrape to deposit their faeces. Adults attacking animals or humans will often defecate as they dive, often successfully fouling the intruder.