The
Indigo Bunting,
Passerina cyanea, is a small
seedA seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
-eating
birdBirds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
in the family Cardinalidae. It is
migratoryBird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
, ranging from southern
CanadaCanada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
to northern
FloridaFlorida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
during the breeding season, and from southern
FloridaFlorida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
to northern
South AmericaSouth America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
during the winter. It often
migratesBird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
by night, using the stars to navigate. Its habitat is farmland, brush areas, and open woodland. The Indigo Bunting is closely related to the
Lazuli BuntingThe Lazuli Bunting, Passerina amoena, is a North American songbird named for the gemstone lapis lazuli.The male is easily recognized by its bright blue head and back , its conspicuous white wingbars, and its light rusty breast and white belly...
, and interbreeds with the latter species where their ranges overlap.
The Indigo Bunting is a small bird, with a length of 11.5–13 cm (4.5–5 in). It displays
sexual dimorphismSexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
in its coloration; the male is a vibrant blue in the summer and a brown color during the winter months, while the female is brown year-round. The male displays brightly colored
plumagePlumage refers both to the layer of feathers that cover a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage vary between species and subspecies and can also vary between different age classes, sexes, and season. Within species there can also be a...
during the breeding season to attract a mate. Nest-building and
incubationIncubation refers to the process by which certain oviparous animals hatch their eggs, and to the development of the embryo within the egg. The most vital factor of incubation is the constant temperature required for its development over a specific period. Especially in domestic fowl, the act of...
are done solely by the female. The diet of the Indigo Bunting consists primarily of insects during the summer months and seeds during the winter months.
Taxonomy
The Indigo Bunting is included in the
familyIn biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Cardinalidae, which is made up of
passerineA passerine is a bird of the order Passeriformes, which includes more than half of all bird species. Sometimes known as perching birds or, less accurately, as songbirds, the passerines form one of the most diverse terrestrial vertebrate orders: with over 5,000 identified species, it has roughly...
birdBirds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
s found in
NorthNorth America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
and
South AmericaSouth America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
, and is one of seven birds in the
genusIn biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
PasserinaThe genus Passerina is a group of birds in the Cardinal family Cardinalidae. Although not directly related to buntings in the family Emberizidae, they are sometimes known as the North American buntings .The males show vivid colours in the breeding season; the...
. It was originally described as
Loxia cyanea by
LinnaeusCarl Linnaeus , also known after his ennoblement as , was a Swedish botanist, physician, and zoologist, who laid the foundations for the modern scheme of binomial nomenclature. He is known as the father of modern taxonomy, and is also considered one of the fathers of modern ecology...
in his 18th-century work,
Systema NaturaeThe book was one of the major works of the Swedish botanist, zoologist and physician Carolus Linnaeus. The first edition was published in 1735...
. The current genus name,
Passerina, is derived from the
LatinLatin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
term
passer for
true sparrowPasser is a genus of Old World sparrows. These sparrows are plump little brown or greyish birds often with black, yellow or white markings. Typically 10–20 cm long, they have short tails and stubby conical beaks...
s and similar small birds, while the species name,
cyanea, is from the Latin word meaning dark or sea blue.
The Indigo Bunting is closely related to the
Lazuli BuntingThe Lazuli Bunting, Passerina amoena, is a North American songbird named for the gemstone lapis lazuli.The male is easily recognized by its bright blue head and back , its conspicuous white wingbars, and its light rusty breast and white belly...
, and interbreeds with the latter species where their ranges overlap, in the
Great PlainsThe Great Plains are a broad expanse of flat land, much of it covered in prairie, steppe and grassland, which lies west of the Mississippi River and east of the Rocky Mountains in the United States and Canada. This area covers parts of the U.S...
. They were declared to form a
superspeciesA superspecies is a group of at least two more or less distinctive species with approximately parapatric distributions. Not all species complexes, whether cryptices or ring species are superspecies, and vice versa, but many are...
by the
American Ornithologists' UnionThe American Ornithologists' Union is an ornithological organization in the USA. Unlike the National Audubon Society, its members are primarily professional ornithologists rather than amateur birders...
in 1983. However, according to sequencing of the mitochondrial cytochrome-b gene of members of the genus
Passerina, it was determined that the Indigo Bunting and Lazuli Bunting are not, in fact, sister
taxa|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...
. The Indigo Bunting is the sister of two sister groups, a “blue” (
Lazuli BuntingThe Lazuli Bunting, Passerina amoena, is a North American songbird named for the gemstone lapis lazuli.The male is easily recognized by its bright blue head and back , its conspicuous white wingbars, and its light rusty breast and white belly...
and
Blue GrosbeakBlue Grosbeak , is a medium-sized seed-eating bird in the same family as the Northern Cardinal, "tropical" or New World buntings, and "cardinal-grosbeaks" or New World grosbeaks....
) and a “painted” (Rosita's Bunting,
Orange-breasted BuntingThe Orange-breasted Bunting is a species of bird in the Cardinalidae family.It is endemic to Mexico.Its natural habitats are subtropical or tropical dry forests and subtropical or tropical dry shrubland. It is more abundant in second growth than in undisturbed forest...
,
Varied BuntingThe Varied Bunting is a species of songbird in the Cardinal family, Cardinalidae.The range of the Varied Bunting stretches from the southern parts of Arizona, New Mexico, and Texas in the United States south throughout Mexico as far as Oaxaca. Small disjunct populations occur in the state of...
, and
Painted BuntingThe Painted Bunting is a species of bird in the Cardinal family, Cardinalidae, that is native to North America.-Taxonomy:...
)
cladeA clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
. This genetic study shows these species
divergedAn evolutionary radiation is an increase in taxonomic diversity or morphological disparity, due to adaptive change or the opening of ecospace. Radiations may affect one clade or many, and be rapid or gradual; where they are rapid, and driven by a single lineage's adaptation to their environment,...
between 4.1 and 7.3 million years ago. This timing, which is consistent with fossil evidence, coincides with a late-
MioceneThe Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...
cooling, which caused the evolution of a variety of western
grasslandGrasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...
habitat* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
s. Evolving to reduce size may have allowed buntings to exploit grass seeds as a food source.
Description
The Indigo Bunting is 11.5–13 cm (4.5–5 in) long, with a wingspan of 20–23 cm (8–9 in). During the breeding season, the adult male has deep blue
plumagePlumage refers both to the layer of feathers that cover a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage vary between species and subspecies and can also vary between different age classes, sexes, and season. Within species there can also be a...
, with a darker crown that verges on purple. The wings and tail are black with blue edges. In fall and winter plumage, the male is similar to the female, but often retains some blue feathers. The adult female is dark brown on the upperparts and lighter brown on the underparts. It has indistinct wing bars and is faintly streaked with dark underneath. The immature bird resembles the female in coloring, although a male may have hints of blue on the tail and shoulders and have darker streaks on the underside. The
beakThe beak, bill or rostrum is an external anatomical structure of birds which is used for eating and for grooming, manipulating objects, killing prey, fighting, probing for food, courtship and feeding young...
is short and conical. In the adult female, the bill is light brown tinged with blue, and in the adult male the upper half is brownish-black while the lower is light blue. The feet and legs are black or gray.
Distribution and habitat
The habitat of the Indigo Bunting is brushy forest edges, open
deciduousDeciduous means "falling off at maturity" or "tending to fall off", and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe...
woods,
second growth woodlandA secondary forest is a forest or woodland area which has re-grown after a major disturbance such as fire, insect infestation, timber harvest or windthrow, until a long enough period has passed so that the effects of the disturbance are no longer evident...
, and
farmlandIn agriculture, the word field refers generally to an area of land enclosed or otherwise and used for agricultural purposes such as:* Cultivating crops* Usage as a paddock or, generally, an enclosure of livestock...
. The breeding
rangeIn biology, the range or distribution of a species is the geographical area within which that species can be found. Within that range, dispersion is variation in local density.The term is often qualified:...
stretches from southern
CanadaCanada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
to
MaineMaine is a state in the New England region of the northeastern United States, bordered by the Atlantic Ocean to the east and south, New Hampshire to the west, and the Canadian provinces of Quebec to the northwest and New Brunswick to the northeast. Maine is both the northernmost and easternmost...
, south to northern
FloridaFlorida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
and eastern
TexasTexas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
, and westward to southern
NevadaNevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...
. The winter range begins in southern Florida and central
MexicoThe United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
and stretches south through the West Indies and
Central AmericaCentral America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
to northern
South AmericaSouth America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
. It has occurred as a
vagrantVagrancy is a phenomenon in biology whereby individual animals appear well outside their normal range; individual animals which exhibit vagrancy are known as vagrants. The term accidental is sometimes also used...
in
AntiguaAntigua , also known as Waladli, is an island in the West Indies, in the Leeward Islands in the Caribbean region, the main island of the country of Antigua and Barbuda. Antigua means "ancient" in Spanish and was named by Christopher Columbus after an icon in Seville Cathedral, Santa Maria de la...
and
BarbudaBarbuda is an island in the Eastern Caribbean, and forms part of the state of Antigua and Barbuda. It has a population of about 1,500, most of whom live in the town of Codrington.-Location:...
,
BarbadosBarbados is an island country in the Lesser Antilles. It is in length and as much as in width, amounting to . It is situated in the western area of the North Atlantic and 100 kilometres east of the Windward Islands and the Caribbean Sea; therein, it is about east of the islands of Saint...
,
DenmarkDenmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...
,
EcuadorEcuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...
,
GermanyGermany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
,
IcelandIceland , described as the Republic of Iceland, is a Nordic and European island country in the North Atlantic Ocean, on the Mid-Atlantic Ridge. Iceland also refers to the main island of the country, which contains almost all the population and almost all the land area. The country has a population...
,
IrelandIreland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...
,
NetherlandsThe Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...
, the
Netherlands AntillesThe Netherlands Antilles , also referred to informally as the Dutch Antilles, was an autonomous Caribbean country within the Kingdom of the Netherlands, consisting of two groups of islands in the Lesser Antilles: Aruba, Bonaire and Curaçao , in Leeward Antilles just off the Venezuelan coast; and Sint...
, Saint Pierre and
MiquelonMiquelon may refer to*Saint Pierre and Miquelon, a territorial collectivity of France**Miquelon-Langlade, the less populous of two communes which are part of Saint Pierre and Miquelon***Miquelon, Miquelon-Langlade, the capital thereof...
,
SerbiaSerbia , officially the Republic of Serbia , is a landlocked country located at the crossroads of Central and Southeast Europe, covering the southern part of the Carpathian basin and the central part of the Balkans...
and the
United KingdomThe United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
.
Behavior
The Indigo Bunting communicates through vocalizations and visual cues. A sharp
chip! call is used by both sexes, and is used as an alarm call if a nest or chick is threatened. A high-pitched, buzzed
zeeep is used as a contact call when the Indigo Bunting is in flight. The song of the male bird is a high-pitched buzzed
sweet-sweet chew-chew sweet-sweet, lasting two to four seconds, sung to mark his
territoryIn ethology the term territory refers to any sociographical area that an animal of a particular species consistently defends against conspecifics...
to other males and to attract females. Each male has a single complex song, which he sings while perched on elevated objects, such as posts, wires, and bush-tops. In areas where the ranges of the
Lazuli BuntingThe Lazuli Bunting, Passerina amoena, is a North American songbird named for the gemstone lapis lazuli.The male is easily recognized by its bright blue head and back , its conspicuous white wingbars, and its light rusty breast and white belly...
and the Indigo Bunting overlap, the males defend territories from each another. Migration takes place in April and May and then again in September and October. The Indigo Bunting often
migratesBird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
during the night, using the stars to direct itself. In captivity, since it cannot migrate, it experiences disorientation in April and May and in September and October if it cannot see the stars from its enclosure.
Breeding
These birds are generally monogamous but not always faithful to their partner. In the western part of their range, they often hybridize with the
Lazuli BuntingThe Lazuli Bunting, Passerina amoena, is a North American songbird named for the gemstone lapis lazuli.The male is easily recognized by its bright blue head and back , its conspicuous white wingbars, and its light rusty breast and white belly...
. Nesting sites are located in dense
shrubA shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
or a low tree, generally 0.3–1 m (1–3 ft) above the ground, but rarely up to 9 m (30 ft). The
nestA bird nest is the spot in which a bird lays and incubates its eggs and raises its young. Although the term popularly refers to a specific structure made by the bird itself—such as the grassy cup nest of the American Robin or Eurasian Blackbird, or the elaborately woven hanging nest of the...
itself is constructed of leaves, coarse grasses, stems, and strips of bark, lined with soft grass or deer hair and is bound with spider web. It is constructed by the female, who cares for the eggs alone. The
clutchA clutch of eggs refers to all the eggs produced by birds or reptiles, often at a single time, particularly those laid in a nest.In birds, destruction of a clutch by predators, , results in double-clutching...
consists of one to four
eggsAn egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
, but usually contains three to four. The eggs are white and usually unmarked, though some may be marked with brownish spots, averaging 18.7 × 13.7 mm (0.7 × 0.5 in) in size. The eggs are
incubatedIncubation refers to the process by which certain oviparous animals hatch their eggs, and to the development of the embryo within the egg. The most vital factor of incubation is the constant temperature required for its development over a specific period. Especially in domestic fowl, the act of...
for 12 to 13 days and the chicks are
altricialAltricial, meaning "requiring nourishment", refers to a pattern of growth and development in organisms which are incapable of moving around on their own soon after hatching or being born...
at hatching. Chicks
fledgeFledge is the stage in a young bird's life when the feathers and wing muscles are sufficiently developed for flight. It also describes the act of a chick's parents raising it to a fully grown state...
10 to 12 days after hatching. Most pairs raise two broods per year, and the male may feed newly fledged young while the females incubate the next clutch of eggs.
The
Brown-headed CowbirdThe Brown-headed Cowbird is a small brood parasitic icterid of temperate to subtropical North America. They are permanent residents in the southern parts of their range; northern birds migrate to the southern United States and Mexico in winter, returning to their summer habitat around March or...
may
parasitizeBrood parasites are organisms that use the strategy of brood parasitism, a kind of kleptoparasitism found among birds, fish or insects, involving the manipulation and use of host individuals either of the same or different species to raise the young of the brood-parasite...
this species. Indigo Buntings abandon their nest if a cowbird egg appears before they lay any of their own eggs, but accept the egg after that point. Pairs with parasitized nests have less reproductive success. The bunting chicks hatch, but have lower survival rates as they must compete with the cowbird chick for food.
Diet
The Indigo Bunting forages for food on the ground or in trees or shrubs. In winter, it often feeds in
flocksA flock is a group of birds conducting flocking behavior in flight, or while foraging. The term is akin to the herd amongst mammals. The benefits of aggregating in flocks are varied and flocks will form explicitly for specific purposes...
with other Indigo Buntings, but is a solitary feeder during the breeding season. During the breeding season, the species eats
insectInsects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s,
seedA seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
s and berries, including
caterpillarCaterpillars are the larval form of members of the order Lepidoptera . They are mostly herbivorous in food habit, although some species are insectivorous. Caterpillars are voracious feeders and many of them are considered to be pests in agriculture...
s,
grasshopperThe grasshopper is an insect of the suborder Caelifera in the order Orthoptera. To distinguish it from bush crickets or katydids, it is sometimes referred to as the short-horned grasshopper...
s,
spiderSpiders are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms...
s,
beetleColeoptera is an order of insects commonly called beetles. The word "coleoptera" is from the Greek , koleos, "sheath"; and , pteron, "wing", thus "sheathed wing". Coleoptera contains more species than any other order, constituting almost 25% of all known life-forms...
s, and grass seeds. The seeds of grasses are the mainstay of its diet during the winter, although
budIn botany, a bud is an undeveloped or embryonic shoot and normally occurs in the axil of a leaf or at the tip of the stem. Once formed, a bud may remain for some time in a dormant condition, or it may form a shoot immediately. Buds may be specialized to develop flowers or short shoots, or may have...
s, and
insectInsects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s are eaten when available. The young are fed mainly insects at first, to provide them with
proteinProteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
. The Indigo Bunting does not drink frequently, generally obtaining sufficient water from its diet.
Status
The species is of Least Concern according to the IUCN, with an estimated range of 5,900,000 km² (3,700,000 mi²) and a population of 28,000,000 individuals. Global population trends have not been quantified, but the species is not believed to approach the thresholds for a population decline warranting an upgrade in conservation status. The criteria for a change in conservation status are a decline of more than 30% in ten years or over three generations.
External links