Animal Diversity Web

Ge­o­graphic Range

The range of red-winged black­birds ex­tends from south­ern Alaska at its north­ern most point, to the Yu­catan penin­sula in the south and cov­ers the greater part of the con­ti­nent reach­ing from the Pa­cific coast of Cal­i­for­nia and Canada to the east­ern seaboard. Win­ter ranges for red-winged black­birds vary by ge­o­graphic lo­ca­tion. North­ern pop­u­la­tions mi­grate south to the south­ern United States and Cen­tral Amer­ica be­gin­ning in Sep­tem­ber or Oc­to­ber (or oc­ca­sion­ally as early as Au­gust). Most west­ern and mid­dle Amer­i­can pop­u­la­tions are non-mi­gra­tory. (Kirschen­baum, 1996; Ya­sukawa and Searcy, 1995)

• Biogeographic Regions
• nearctic
  • native
• neotropical
  • native

Habi­tat

Red-winged black­birds roost and breed in a va­ri­ety of habi­tats, but tend to pre­fer wet­lands. They have been known to live in fresh and salt­wa­ter marshes. On drier ground, red-winged black­birds grav­i­tate to­wards open fields (often in agri­cul­tural areas) and lightly wooded de­cid­u­ous forests. In win­ter red-winged black­birds are most often found in open fields and crop­lands. (Kirschen­baum, 1996; "Red-winged Black­bird", 1996; Ya­sukawa and Searcy, 1995)

• Habitat Regions
• temperate
• tropical
• terrestrial

• Terrestrial Biomes
• savanna or grassland

• Aquatic Biomes
• brackish water

• Wetlands
• marsh
• swamp

• Other Habitat Features
• suburban
• agricultural
• riparian
• estuarine

Phys­i­cal De­scrip­tion

Eas­ily dis­tin­guished by their glossy black feath­ers and red and yel­low epaulets at the shoul­der, males are the more brightly col­ored of the two sexes. Fe­males tend to be dusty or brown­ish in color with dark stripes on their un­der­sides. Fe­males re­sem­ble large spar­rows and are often rec­og­nized by their off-white eye­brow mark­ings. Both males and fe­males have dark legs and claws. The beak of male red-winged black­birds tends to be to­tally black, whereas the beak of fe­male red-winged black­birds is dark brown on top with lighter brown on the un­der­side. Both males and fe­males have sharply pointed beaks. (Cleary, 2002; Jen­nings, 2000; Kirschen­baum, 1996; "Red-winged Black­bird", 1996; Neff, 1997; Ya­sukawa and Searcy, 1995)

Both male and fe­male adult red-winged black­birds are ap­prox­i­mately 22 cm long, weigh 41.6 to 70.5 g and have a wingspan of 30 to 37 cm. Young males and fe­males re­sem­ble adult fe­males in col­oration. Males un­dergo a tran­si­tional stage in which red epaulets ap­pear or­ange in color be­fore reach­ing their adult col­oration. Olson (1994) showed that the av­er­age basal meta­bolic rate for adults in his ex­per­i­ments was 656 cm cubed/oxy­gen per minute and that the rate for three-day-old birds was 296 cm cubed/oxy­gen per minute. (Jen­nings, 2000; Kirschen­baum, 1996; "Red-winged Black­bird", 1996; Olson, 1994; Olson, 2001; Ya­sukawa and Searcy, 1995)

• Other Physical Features
• endothermic
• homoiothermic
• bilateral symmetry

• Sexual Dimorphism
• male larger
• sexes colored or patterned differently
• male more colorful

• Range mass

  41.6 to 70.5 g

  1.47 to 2.48 oz

• Range length

  18 to 24 cm

  7.09 to 9.45 in

• Average length

  22 cm

  8.66 in

• Range wingspan

  30 to 37 cm

  11.81 to 14.57 in

Re­pro­duc­tion

Red-winged black­birds are ex­tremely polyg­y­nous with as many as 15 fe­males nest­ing in the ter­ri­tory of a sin­gle male. On av­er­age, a sin­gle male has roughly 5 fe­males. Al­though cop­u­la­tion oc­curs mostly be­tween the sov­er­eign male and those fe­males that in­habit his ter­ri­tory, roam­ing males are known to mate with the fe­males on other ter­ri­to­ries. These be­hav­iors seem to in­crease the chances of suc­cess­ful re­pro­duc­tion within a given mat­ing sea­son, com­pen­sat­ing for broods and in­di­vid­u­als lost to nest-pre­da­tion and nest par­a­sitism. (Ya­sukawa and Searcy, 1995)

Mat­ing rit­u­als begin with the song of the male. Fe­males often do not re­turn songs until they have es­tab­lished them­selves in the ter­ri­tory of a male. Male pre-coital dis­plays in­clude vo­cal­iza­tion in a crouched po­si­tion with rapid and highly con­spic­u­ous flut­ter­ing of the wings. The fe­male re­sponds with a sim­i­lar crouch and vo­cal­iza­tion. Mat­ing oc­curs in the egg-lay­ing pe­riod or just prior and is char­ac­ter­ized by a brief con­tact be­tween the cloa­cal vents of the male and the fe­male. (Ya­sukawa and Searcy, 1995)

• Mating System
• polygynous
• polygynandrous (promiscuous)

Breed­ing be­gins in the early spring and con­tin­ues until mid-sum­mer. Fe­males may raise as many as three broods in a sin­gle sea­son, al­though the av­er­age is 1.7 broods per sea­son. Fe­males choose nest­ing sites most often in wet­land or agri­cul­tural areas (al­though a wide va­ri­ety of nest­ing habi­tats are know to be ex­ploited) and males per­form a nest­ing dis­play, which con­sti­tutes his main in­volve­ment in the nest build­ing process. Nest build­ing be­gins be­tween March and May. Usu­ally, the fur­ther south you go, the ear­lier the nest is built. After a fe­male ac­cepts the male and his site, the nest is built in or near marsh­land or moist, grassy areas. Plant ma­te­ri­als, such as cat­tail stalks, are woven to­gether to form a bas­ket above water level, and soft ma­te­ri­als are used to line the nest. Three to five pale green­ish-blue, black or pur­ple streaked eggs are laid per clutch. Each egg is ap­prox­i­mately 2.5 by 1.8 cm. Nests can be com­pleted in as lit­tle as a sin­gle day, es­pe­cially if no mud-lin­ing is con­structed.

Clutch size is from 3 to 7 eggs and the eggs are in­cu­bated for 3 to 11 days. Chicks fledge in 10 to 14 days and are in­de­pen­dent in 2 to 3 weeks. Ju­ve­niles usu­ally reach sex­ual ma­tu­rity in 2 to 3 years. (Ya­sukawa and Searcy, 1995)

• Key Reproductive Features
• iteroparous
• seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• fertilization
• oviparous

• Breeding interval

  Females may raise as many as three broods in a single season, although the average is 1.7 broods per season.

• Breeding season

  Breeding begins in the early spring and continues until mid-summer.

• Range eggs per season

  3 to 7

• Average eggs per season

  4

• Average eggs per season

  4

  AnAge

• Range time to hatching

  11 to 13 days

• Average time to hatching

  11 days

• Range fledging age

  14 to 10 days

• Average fledging age

  14 days

• Range time to independence

  2 to 3 weeks

• Average time to independence

  2 weeks

• Range age at sexual or reproductive maturity (female)

  2 to 2 years

• Range age at sexual or reproductive maturity (male)

  2 to 4 years

In­cu­ba­tion is the sole re­spon­si­bil­ity of fe­males. Red-winged black­bird eggs tend to hatch at dif­fer­ent times and the mother will con­tinue to in­cu­bate until the last egg has hatched. Nestlings are fed al­most im­me­di­ately after hatch­ing. Par­ents often begin with smaller por­tions and in­crease food amounts pro­gres­sively. Young red-winged black­birds are fed small arthro­pods, es­pe­cially Odonata (drag­on­flies and dam­selflies), Lep­i­doptera (moths and but­ter­flies), and Diptera (true flies). The nestlings are fed pri­mar­ily by the fe­male al­though the male will, at times, take part in the feed­ing process. In cases in which the mother is ab­sent, males are known to take over feed­ing re­spon­si­bil­i­ties for the brood. Fledg­lings leave the nest after 14 days and are fed by the fe­male and, to a lesser de­gree, the male for two to three weeks be­fore join­ing a flock of fe­males. Within a year most red-winged black­birds have joined mixed flocks. (Ya­sukawa and Searcy, 1995)

• Parental Investment
• no parental involvement
• altricial
• pre-fertilization
  • protecting
    • female
• pre-hatching/birth
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • male
    • female
  • protecting
    • male
    • female
• pre-independence
  • provisioning
    • male
    • female
  • protecting
    • male
    • female

Lifes­pan/Longevity

In the wild, red-winged black­birds live 2.14 years, on av­er­age. The olded recorded red-winged black­bird in the wild lived 15 years and 9 months. (Ya­sukawa and Searcy, 1995)

• Range lifespan
  Status: wild

  20 (high) years

• Average lifespan
  Status: wild

  2.14 years

• Average lifespan
  Status: wild

  189 months

  Bird Banding Laboratory

Be­hav­ior

As mi­gra­tory birds, red-winged black­birds share many char­ac­ter­is­tics with re­lated species. They are strong fliers that will often mi­grate in flocks of a thou­sand or more. Roost­ing is often com­mu­nal, re­sult­ing in large, cen­tral­ized pop­u­la­tions. Red-winged black­birds are largely di­ur­nal, spend­ing most of their day for­ag­ing. Males de­fend ter­ri­to­ries dur­ing the mat­ing sea­son. As the mat­ing sea­son pro­gresses, both males and fe­males will spend more time within their ter­ri­tory or the ter­ri­tory of their mate. Al­though fight­ing among red-winged black­birds is not all that com­mon, even among males, it is known to occur. Males chase fe­males at top speed dur­ing breed­ing sea­sion. Be­cause of their broad range and ten­dency to col­o­nize large roost­ing areas, red-winged black­birds are ex­tremely com­mon, and are easy to find in the mat­ing sea­son when singing and sex­ual dis­plays make them more vis­i­ble. ("Perch­ing Birds: Red-winged Black­bird, Age­laius phoeniceus", 2000; Kirschen­baum, 1996; "Red-winged Black­bird", 1996; Ya­sukawa and Searcy, 1995)

• Key Behaviors
• flies
• diurnal
• motile
• migratory
• territorial
• social

• Range territory size

  153 to 29235 m^2

• Average territory size

  2000 m^2

Home Range

Home range and ter­ri­tory size vary greatly among red-winged black­birds given their broad ge­o­graphic range and ex­ten­sive use of vary­ing habits. Males tend to con­trol ter­ri­to­ries of ap­prox­i­mately 2,000 square me­ters, but some ter­ri­to­ries in marshes may be as small as 153 m^2, and some ter­ri­to­ries in up­land habi­tat may be as large as 29,235 m^2. Fe­males will oc­cupy the ter­ri­tory of a sin­gle male, along with many other fe­males. Males will de­fend their ter­ri­tory against other male red-winged black­birds and also against other species of bird, in­clud­ing tri­col­ored black­birds and yel­low-headed black­birds, usu­ally yield­ing to larger bird species. Birds in Costa Rica de­fend ter­ri­to­ries that are two to four times the size of tem­per­ate birds to the north. (Ya­sukawa and Searcy, 1995)

Com­mu­ni­ca­tion and Per­cep­tion

Males learn songs from other males. Both males and fe­males have a va­ri­ety of calls, some of which are the same. Only the males pro­duce flight calls, which sig­nal their exit from the ter­ri­tory. Both males and fe­males em­ploy dis­tress and alarm calls which dif­fer with the na­ture of the threat. Spe­cific calls seem to com­mu­ni­cate the pres­ence of spe­cific preda­tors, such as rac­coons or Amer­i­can crows. Short con­tact calls are also quite com­mon, es­pe­cially be­tween a ter­ri­to­r­ial male and the fe­males in his ter­ri­tory. Threat calls are used to ward off preda­tors, other birds and other red-winged black­birds. Courtship calls vary lit­tle be­tween males and fe­males and are used only in the breed­ing sea­son. Male songs are used to an­nounce ter­ri­to­r­ial bound­aries and to at­tract mates. Fe­male songs occur in the early breed­ing sea­son and are most com­mon be­fore the in­cu­ba­tion pe­riod.

Male red-winged black­birds utter their fa­mil­iar ter­ri­to­r­ial and mate at­trac­tion song of "oak-a-lee" or "konkeree" in the spring. The last syl­la­ble is given more em­pha­sis as a scratchy or buzzy trill. The com­mon call used by both males and fe­males is a "check" call. Males may utter a whis­tled "cheer" or "peet" call if alarmed. Other calls made by the male in­clude a "seet," a "chuck," or a "cut." Fe­males may utter a short chat­ter or sharp scream. A pre-mat­ing call, "ti-ti-ti," may be ut­tered by both sexes. (Ya­sukawa and Searcy, 1995)

Vi­sual dis­plays are also a key form of com­mu­ni­ca­tion, es­pe­cial be­fore and dur­ing mat­ing. Males often use vi­sual dis­plays in order to at­tract fe­males to their ter­ri­to­ries and to de­fend their ter­ri­to­ries and mates. An ex­am­ple is the "song spread" dis­play. Males fluff their plumage, raise their shoul­ders, and spread their tail as they sing. As the dis­play be­comes more in­tense, the wings are more arched with the shoul­ders show­ing more promi­nently. Fe­males will also en­gage in a "song spread" dis­play di­rected at each other early in the breed­ing sea­son. One pos­si­bil­ity is that a fe­male will de­fend a sub-ter­ri­tory within the male's ter­ri­tory. Fe­males will en­gage in a "wing flip" dis­play when a dis­tur­bance pre­vents them from re­turn­ing to the nest. (Ya­sukawa and Searcy, 1995)

• Communication Channels
• visual
• acoustic

• Perception Channels
• visual
• tactile
• acoustic
• chemical

Food Habits

Red-winged black­birds tend to be gen­er­al­ized feed­ers, con­sum­ing a greater amount of plant tis­sue in the non-breed­ing sea­son and a greater amount of an­i­mal ma­te­r­ial in the breed­ing sea­son. Red-winged black­birds will feed on al­most any plant ma­te­r­ial they can con­sume, pre­fer­ring seeds and agri­cul­tural prod­ucts, such as corn and rice. Adult red-winged black­birds will con­sume a wide va­ri­ety of foods in­clud­ing snails, frogs, fledg­ling birds, eggs, car­rion, worms and a wide array of arthro­pods. In­sects, es­pe­cially Odonata (drag­on­flies and dam­selflies), Lep­i­doptera (but­ter­flies and moths), and Diptera (true flies) are pre­ferred, al­though arach­nids and other in­sect and non-in­sect arthro­pods are con­sumed. For the most part, red-winged black­birds feed on what­ever they can find, pick­ing in­sects out of plants and feed­ing on seeds and plant ma­te­r­ial. At times, red-winged black­birds will hunt using their beaks for gap­ing (open­ing up of crevices in plant ma­te­r­ial with the beak). Red-winged black­birds will also catch in­sects in flight. (Kirschen­baum, 1996; Ya­sukawa and Searcy, 1995)

• Primary Diet
• omnivore

• Animal Foods
• birds
• amphibians
• reptiles
• eggs
• carrion
• insects
• terrestrial non-insect arthropods
• terrestrial worms

• Plant Foods
• roots and tubers
• wood, bark, or stems
• seeds, grains, and nuts

Pre­da­tion

As a re­sult of high pre­da­tion rates, es­pe­cially of eggs and young, red-winged black­birds have de­vel­oped a num­ber of anti-preda­tor adap­ta­tions. Group nest­ing is one such trait which re­duces the risk of in­di­vid­ual pre­da­tion by in­creas­ing the num­ber of alert par­ents. Nest­ing over water re­duces the like­li­hood of pre­da­tion as do alarm calls. Nests, in par­tic­u­lar, offer a strate­gic ad­van­tage over preda­tors in that they are often well con­cealed in thick, wa­ter­side reeds and po­si­tioned at a height of one to two me­ters. Males often act as sen­tinels, em­ploy­ing a va­ri­ety of calls to de­note the kind and sever­ity of dan­ger. Mob­bing, es­pe­cially by males, is also used to scare off un­wanted preda­tors, al­though mob­bing often tar­gets large an­i­mals and man-made de­vices by mis­take. The brown­ish col­oration of the fe­male may also serve as an anti-preda­tor trait in that it may pro­vide cam­ou­flage for her and her nest (while she is in­cu­bat­ing).

Known preda­tors in­clude: racoons, Amer­i­can mink, black-billed mag­pies, marsh wrens, owls (fam­ily St­rigi­dae) and hawks (order Fal­coni­formes). ("Perch­ing Birds: Red-winged Black­bird, Age­laius phoeniceus", 2000; Jen­nings, 2000; "Red-winged Black­bird", 1996; Neff, 1997; Ya­sukawa and Searcy, 1995)

• Anti-predator Adaptations
• aposematic
• cryptic

• Known Predators

  • raccoons (Procyon lotor)
  • American mink (Neovison vison)
  • black-billed magpies Pica pica
  • marsh wrens Cistothorus palustris
  • owls (Strigiformes)
  • diurnal raptors (Falconiformes)

Ecosys­tem Roles

As highly gen­er­al­ized for­agers and preda­tors, red-winged black­birds can have a great and last­ing im­pact on their en­vi­ron­ment. By con­trol­ling in­sect pop­u­la­tions through pre­da­tion and weed pop­u­la­tions through the con­sump­tion of seeds, red-winged black­birds allow larger plants and crops to flour­ish. Para­dox­i­cally, red-winged black­birds can also dev­as­tate plant growth and crop yields by feed­ing on the very plants their pre­da­tion pro­tects. As one of the most nu­mer­ous species of birds on the con­ti­nent, red-winged black­birds also play key roles in the dis­per­sal of other species. Be­cause red-winged black­birds tend to flock and roost in such large num­bers the sur­vival of other species of birds that en­croach upon their ter­ri­tory must surely be af­fected by their pres­ence. Large roost­ing habi­tats can also greatly af­fect the phys­i­cal ter­rain. In short, red-winged black­birds are so nu­mer­ous and ac­tive that their pres­ence and nat­ural be­hav­ior alone is enough to im­pact an ecosys­tem in a very vis­i­ble way. (Jen­nings, 2000; Kirschen­baum, 1996; "Red-winged Black­bird", 1996; Ya­sukawa and Searcy, 1995)

• Ecosystem Impact
• disperses seeds

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Red-winged black­birds have been known to feed on the seeds of nu­mer­ous weeds that are detri­men­tal to agri­cul­tural pro­duc­tion. They also con­trol in­sect pop­u­la­tions, which can dev­as­tate agri­cul­tural yields. (Ya­sukawa and Searcy, 1995)

• Positive Impacts
• controls pest population

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

De­spite their con­sump­tion of the seeds of un­wanted weed pests, red-wing black­birds have been known to cause great agri­cul­tural dam­age due to their colo­nial roost­ing habits and taste for agri­cul­tural prod­ucts. Red-winged black­birds often open the husks of de­vel­op­ing corn stalks to feed on corn ker­nels. They are also known to feed on rice pad­dies and sun­flower seeds. This con­sump­tion of ripen­ing crops has lead many agri­cul­tur­al­ists to em­ploy ex­tremely ef­fec­tive and often in­hu­mane tac­tics in bat­tling red-winged black­bird pop­u­la­tions. These tac­tics in­clude the fre­quent use of traps, poi­sons, and Avi­tol, a chem­i­cal agent that causes birds to be­have in ab­nor­mal ways. Sur­fac­tants, or wet­ting agents, have also caused con­sid­er­able dam­age to red-winged black­birds. These de­ter­gents break down the wa­ter­proof­ing prop­er­ties of the black­bird's feath­ers mak­ing them ex­tremely vul­ner­a­ble to low tem­per­a­tures. Be­cause of the long his­tory of hu­man-black­bird con­flict and their con­tin­ued threat to agri­cul­tural ini­tia­tives many of these tech­niques are used to this day. Less harm­ful meth­ods of red-winged black­bird con­trol in­clude the use of noise­mak­ers and the re­duc­tion of post-har­vest crop waste, which at­tracts hun­gry red-winged black­birds to farm­land. (Ya­sukawa and Searcy, 1995)

• Negative Impacts
• crop pest

Con­ser­va­tion Sta­tus

As one of the most com­mon, wide­spread, and nu­mer­ous birds in North Amer­ica, lit­tle is done to pro­tect red-winged black­birds from the ef­fects of habi­tat loss and ur­ban­iza­tion. Be­cause they can sur­vive in a wide array of habi­tats, many pop­u­la­tions can over­come losses of nat­ural ter­rain. Nonethe­less, red-winged black­birds thrive in wet­land areas and with the loss of nat­ural wet­lands it is likely that this species will suf­fer. This species is a mi­gra­tory bird, and is pro­tected under the U.S. Mi­gra­tory Bird Treaty Act. (Jen­nings, 2000; Kirschen­baum, 1996; "Red-winged Black­bird", 1996; Ya­sukawa and Searcy, 1995)

• IUCN Red List

  Least Concern
  More information

• IUCN Red List

  Least Concern
  More information

• US Migratory Bird Act

  Protected

• US Federal List

  No special status

• CITES

  No special status

• State of Michigan List

  No special status

Con­trib­u­tors

Alaine Cam­field (ed­i­tor), An­i­mal Di­ver­sity Web.

An­thony Rosen­thal (au­thor), Uni­ver­sity of Michi­gan-Ann Arbor, Phil Myers (ed­i­tor), Mu­seum of Zo­ol­ogy, Uni­ver­sity of Michi­gan-Ann Arbor.

Ref­er­ences

Geor­gia Mu­seum of Nat­ural His­tory and Geor­gia De­part­ment of Nat­ural Re­sor­ces. 2000. "Perch­ing Birds: Red-winged Black­bird, Age­laius phoeniceus" (On-line). Geor­gia Wildlife Web. Ac­cessed March 31, 2004 at http://​museum.​nhm.​uga.​edu/​gawildlife/​birds/​passeriformes/​aphoeniceus.​html.

Na­tional Wildlife Fed­er­a­tion. 1996. "Red-winged Black­bird" (On-line). Ac­cessed March 31, 2004 at http://​www.​enature.​com/​partners/​nwf/​showSpeciesLG_​nwf.​asp?​showType=4&​rgnID=1599&​curGroupID=1&​curPageNum=284&​recnum=BD0326.

Cleary, K. 2002. "Typ­i­cal Birds that Host the West Nile Virus" (On-line). Ac­cessed March 31, 2004 at http://​www.​nwhc.​usgs.​gov/​research/​west_​nile/​wnv_​bird_​id.​html.

Jen­nings, H. 2000. "Red-winged Black­bird, Age­laius phoeniceus" (On-line). Ac­cessed March 31, 2004 at http://​www.​elwas.​org/​highlights/​data/​20021013_​211842454.

Kirschen­baum, M. 1996. "Red-winged Black­bird, Age­laius phoeniceus" (On-line). Ac­cessed March 31, 2004 at http://​nasa.​utep.​edu/​chih/​theland/​animals/​birds/​aphoeni.​htm.

Neff, J. 1997. "Red-winged Black­bird (Age­laius phoeniceus)" (On-line). Ac­cessed March 31, 2004 at http://​lupus.​northern.​edu:​90/​natsource/​BIRDS/​Redwin1.​htm.

Olson, J. 2001. On­togeny of cata­bolic and mor­pho­log­i­cal prop­er­ties of skele­tal mus­cle of the red-winged black­bird (Age­laius phoeniceus). Jour­nal of Com­par­i­tive Phys­i­ol­ogy, 171(7): 527-542.

Olson, J. 1994. The On­togeny of Shiv­er­ing Ther­mo­ge­n­e­sis in the Red-winged Black­bird (Age­laius phoeniceus). Jour­nal of Ex­per­i­men­tal Bi­ol­ogy, 191(1): 59-88.

Ya­sukawa, K., W. Searcy. 1995. Red-winged Black­bird (Age­laius phoeniceus). A Poole, F Gill, eds. The Birds of North Amer­ica, Vol. 184. The Acad­emy of Nat­ural Sci­ences, Philadel­phia, and The Amer­i­can Or­nithol­o­gist's Union, Wash­ing­ton, D.C.