Animal Diversity Web

Ge­o­graphic Range

Vireo oli­vaceus is a mi­gra­tory species that in­hab­its the Nearc­tic and Neotrop­i­cal re­gions. Dur­ing the non-breed­ing sea­son, this species in­hab­its north­east­ern South Amer­ica and is found east of the Andes Moun­tains as far south as Uruguay. In early spring, Vireo oli­vaceus trav­els north through south­ern Cen­tral Amer­ica, along the Gulf coast and across Cuba, Haiti and the Do­mini­can Re­pub­lic. Vireo oli­vaceus breeds across nearly all of the United States, ex­clud­ing the south­west re­gion. Red-eyed vireos are rarely found south of Ore­gon or west of Col­orado. Their breed­ing range ex­tends as far north as the North­west Ter­ri­to­ries and stretches from nearly coast to coast across south­ern Canada. Some Vireo oli­vaceus pop­u­la­tions re­main in South Amer­ica to breed and move as far south as north­ern Ar­gentina, but stay east of the Andes Moun­tains. (Dun­ford, et al., 2002; Sib­ley, 2000)

• Biogeographic Regions
• nearctic
  • native
• neotropical
  • native

Habi­tat

Vireo oli­vaceus prefers to breed in de­cid­u­ous or mixed for­est with dense canopy cover. In conif­er­ous dom­i­nated stands they are most often found near ri­par­ian areas. They also breed in forested urban parks or ceme­ter­ies with old-growth trees that pro­vide a dense canopy. They may be found any­where from sea level to 2,000 m above in the Rocky Moun­tains.

In mi­gra­tion, Vireo oli­vaceus can be found in habi­tats sim­i­lar to those used for breed­ing. They visit a slightly broader range of habi­tats dur­ing mi­gra­tion and may be found in for­est edge, sec­ond growth for­est, or cit­rus groves.

Dur­ing the non-breed­ing sea­son, red-eyed vireos pre­fer rain forests, sec­ond growth forests, plan­ta­tions and for­est edge habi­tats. They se­lect habi­tats lo­cated from sea level to 3,000 m above.

These vireos are largely con­sid­ered for­est in­te­rior species but re­cent re­search is sug­gest­ing oth­er­wise. Red-eyed vireos have been shown to se­lect sites based on high lev­els of canopy cover and may be in­flu­enced very lit­tle by edge ef­fect or frag­men­ta­tion. (Cim­prich, et al., 2000; Dun­ford, et al., 2002; Siepiel­ski, et al., 2001)

• Habitat Regions
• temperate
• tropical
• terrestrial

• Terrestrial Biomes
• taiga
• forest
• rainforest

• Other Habitat Features
• urban
• riparian

• Range elevation

  0 to 3000 m

  0.00 to 9842.52 ft

Phys­i­cal De­scrip­tion

Like all Vireo species, Vireo oli­vaceus is a small, perch­ing song­bird with rel­a­tively large, hooked bills. They mea­sure 15.24 cm in length, fea­ture a 25.4 cm wingspan, and weigh an av­er­age 18 g. Red-eyed vireos are rec­og­nized for their dark red iri­des that adults fea­ture. How­ever, this char­ac­ter­is­tic is rarely seen in the field as they are often at the tops of trees. They are olive-green across the nape, back, wings and tail. Throat, breast, and belly are bright white, while the under tail coverts and flanks are pale yel­low. These vireos have a gray crown with a con­trast­ing thick, white su­per­cil­ium and a dark gray eye-line. Bills and legs are dark gray to black. Vireo oli­vaceus ex­hibits no sex­ual di­mor­phism and ju­ve­niles re­sem­ble adults, but are more gray-ish green over­all.

Closely re­lated species in­clude Vireo flavoviridis and Vireo al­til­o­quus. Their breed­ing ranges do not over­lap, but they may over­win­ter in sim­i­lar re­gions of South Amer­ica. Vireo flavoviridis can be dis­tin­guished by brighter and more ex­ten­sive yel­low under tail coverts, flanks and cheeks. They also have a pale, larger bill as op­posed to the dark smaller bill of Vireo oli­vaceus. Vireo al­til­o­quus is over­all brown­ish-green, with very pale yel­low on the under tail coverts and flanks, as well as a defin­ing black "whisker" or lat­eral stripe down the throat. Each of these species is best de­fined by song. (Cim­prich, et al., 2000; Sib­ley, 2000)

• Other Physical Features
• endothermic
• homoiothermic
• bilateral symmetry

• Sexual Dimorphism
• sexes alike

• Average mass

  17 g

  0.60 oz

• Average length

  15.2 cm

  5.98 in

• Average wingspan

  25.4 cm

  10.00 in

Re­pro­duc­tion

Vireo oli­vaceus is a monog­a­mous species, but the length of pair-bonds is cur­rently un­known. Males ar­rive early at the breed­ing grounds to es­tab­lish ter­ri­tory and pair for­ma­tion oc­curs shortly after the fe­males ar­rive. No courtship rit­u­als have been ob­served, but males often chase po­ten­tial mates and oc­ca­sion­ally pin the fe­males to the ground. Red-eyed vireos have been ob­served to per­form a "sway­ing" dis­play, but this is cur­rently hy­poth­e­sized to be used to ap­pease in­di­vid­u­als rather than court. (Cim­prich, et al., 2000; Nolan, 1962)

• Mating System
• monogamous

Males ar­rive on the breed­ing grounds from mid-March to early May and im­me­di­ately es­tab­lish ter­ri­to­ries. First year in­di­vid­u­als are able to breed. Fe­males ar­rive 3 to 15 days later and se­lect a nest­ing site within a male's ter­ri­tory. Nests are gen­er­ally con­structed in the crook of a branch in the mid- to un­der­story layer. The most suc­cess­ful nests are well con­cealed from above by fo­liage. Fe­male red-eyed vireos build the cup-shaped nests using grasses, twigs, roots, bark strips, or spi­der­webs. The fe­males line their nests with softer ma­te­ri­als such as grass, pine nee­dles, and oc­ca­sion­ally an­i­mal hair.

Once the nest is con­structed, fe­males lay an av­er­age clutch of 4 white, spot­ted eggs. Fe­males per­form all in­cu­ba­tion which lasts be­tween 11 and 14 days. After the young hatch, they are tended by both par­ents. The tiny hatch­lings ini­tially weigh be­tween 1.5 and 1.8 g. The young fledge after 10 to 12 days and reach in­de­pen­dence after an ad­di­tional 25 days when the par­ents stop pro­vid­ing food. (Cim­prich, et al., 2000; Ehrlich, et al., 1988)

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

• Breeding interval

  Red-eyed vireos breed once yearly.

• Breeding season

  The breeding season for red-eyed vireos occurs from mid-April to August.

• Range eggs per season

  3 to 5

• Range time to hatching

  11 to 14 days

• Range fledging age

  10 to 12 days

• Range time to independence

  35 to 37 days

• Average age at sexual or reproductive maturity (female)

  <1 years

• Average age at sexual or reproductive maturity (male)

  <1 years

Male Vireo oli­vaceus in­vest time and en­ergy in es­tab­lish­ing suit­able nest­ing ter­ri­to­ries. Males fre­quently en­gage in chases and phys­i­cal ag­gres­sion to de­fend their ter­ri­to­ries. Once fe­males ar­rive, they pro­vide the ma­jor­ity of parental care. Fe­males se­lect suit­able nest­ing sites and com­plete all nest con­struc­tion. In­cu­ba­tion and sub­se­quent brood­ing of the young is also per­formed solely by the fe­male. Hatch­lings are al­tri­cial at birth, which re­quires sig­nif­i­cant parental care to feed, pro­tect, and warm the de­fense­less young. Both par­ents ac­tively con­sume or re­move egg shells from the nest, which likely re­duces the chance of pre­da­tion by re­mov­ing the scent of eggs. Fecal sacs are also re­moved by both par­ents, mostly by fe­males, and are con­sumed until the 7th day post-hatch. Males con­tribute to feed­ing the hatch­lings, but fe­males pro­vide the ma­jor­ity of food. Par­ents con­tinue to feed the young fre­quently until 15 or 16 days post-fledg­ing, but then dras­ti­cally de­crease feed­ing until 25 days post-fledge when feed­ing ceases. (Cim­prich, et al., 2000)

• Parental Investment
• altricial
• male parental care
• female parental care
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • male
    • female
• pre-weaning/fledging
  • provisioning
    • male
    • female
  • protecting
    • male
    • female
• pre-independence
  • provisioning
    • male
    • female
  • protecting
    • male
    • female

Lifes­pan/Longevity

The an­nual adult sur­vivor­ship for Vireo oli­vaceus is es­ti­mated at 0.58. Sur­vival rates for chicks post-fledg­ing is much lower, es­ti­mated at 0.28. The old­est known red-eyed vireo was banded as an adult in 1963 and re­cap­tured in 1972, mak­ing the in­di­vid­ual at least 10 years old. Vireo oli­vaceus is not kept in cap­tiv­ity. Causes of mor­tal­ity are poorly un­der­stood but likely in­clude par­a­sites, brood par­a­sitism, pre­da­tion, and stress of long-dis­tance mi­gra­tion. Many birds do not sur­vive mi­gra­tion and per­ish in col­li­sions with build­ings or other tall ob­jects dur­ing night jour­neys. (Cim­prich, et al., 2000; Klimkiewicz, et al., 1983; Noon and Sauer, 1992)

• Range lifespan
  Status: wild

  10 (high) years

Be­hav­ior

Vireo oli­vaceus is a Neotrop­i­cal mi­grant that per­forms long-dis­tance mi­gra­tions twice yearly be­tween North and South Amer­ica. On mi­gra­tory flights, these birds are noc­tur­nal and will join mixed species groups or groups with up to 30 other vireos. They may stay in mixed species groups on the win­ter­ing grounds in South Amer­ica, but they are soli­tary and ter­ri­to­r­ial dur­ing the breed­ing sea­son. Vireo oli­vaceus is a more ag­gres­sive species that will chase or phys­i­cally at­tack oth­ers of ei­ther sex. They spend much of their time in the upper to mid canopy lev­els of dense for­est, and are most ac­tive dur­ing dawn and dusk dur­ing the breed­ing sea­son. (Cim­prich, et al., 2000)

• Key Behaviors
• arboreal
• flies
• diurnal
• crepuscular
• motile
• migratory
• solitary
• territorial

• Range territory size

  8,600 to 37,100 m^2

Home Range

Dur­ing the breed­ing sea­son, males de­fend a ter­ri­tory that ranges in size from 0.86 to 3.71 hectares. Fe­males will travel slightly out­side of their mates' ter­ri­tory. Ter­ri­tory size ap­pears to be den­sity de­pen­dent, as when more males in­habit an area, their in­di­vid­ual ter­ri­tory sizes shrink. (Cim­prich, et al., 2000)

Com­mu­ni­ca­tion and Per­cep­tion

Vireo oli­vaceus is a vocal species that is fre­quently heard call­ing from the upper for­est canopy. Their pri­mary call is mostly two-note phrases that are mnemon­i­cally de­scribed as "Look up! See me? Over here! Do you hear me?" Male red-eyed vireos are one of the most per­sis­tent singers of all birds and have been recorded singing 10,000 songs in one day. These songs are used to de­lin­eate ter­ri­tory bound­aries, and are only sung by males. Both sexes use a call de­scribed as a cat­bird-like mew usu­ally used in ag­gres­sive en­coun­ters or when preda­tors are near.

Vireo oli­vaceus also uses pos­tures and body move­ments to vi­su­ally com­mu­ni­cate. These pos­tures have been iden­ti­fied as Crest-erect Alert, Head-for­ward Threat, Tail-Fan­ning, and Gap­ing dis­plays. All of these dis­plays are used in ag­gres­sive en­coun­ters be­tween ei­ther sexes and are usu­ally fol­lowed by peck­ing if an in­di­vid­ual does not re­treat. Like all birds, red-eyed vireos per­ceive their en­vi­ron­ments through au­di­tory, vi­sual, tac­tile and chem­i­cal stim­uli. ("Whatbird.​com:​ Field Guide to Birds of North Amer­ica", 2007; Cim­prich, et al., 2000)

• Communication Channels
• visual
• tactile
• acoustic

• Perception Channels
• visual
• tactile
• acoustic
• chemical

Food Habits

Vireo oli­vaceus is pri­mar­ily an in­sec­tiv­o­rous species, but also oc­ca­sion­ally eats fruit. Diet changes sea­son­ally from nearly ex­clu­sively in­sects dur­ing the spring and sum­mer to nearly all fruit dur­ing the win­ter. Main food sources in­clude but­ter­fly lar­vae (Lep­i­doptera), bee­tles (Coleoptera), mos­qui­toes (Diptera), ci­cadas (Ho­moptera), wasps and ants (Hy­menoptera), grasshop­pers (Or­thoptera) and drag­on­flies (Odonata). These vireos also con­sume snails (Mol­lusca) and spi­ders (Arach­nida), al­though rarely. Red-eyed vireos are fo­liage glean­ers and cap­ture in­sects set­ting on leaves or stems while perched, fly­ing or hang­ing up­side-down. There have been a few ob­ser­va­tions of red-eyed vireos drink­ing water that had col­lected on leaves.

Fruits and trees often uti­lized by red-eyed vireos in­clude dew­ber­ries (Rubus), el­der­ber­ries (Sam­bu­cus canaden­sis), Vir­ginia creeper (Partheno­sisus quin­que­fo­lia), sas­safras (Sas­safras al­bidum), spice­bush (Lin­dera ben­zoin), dog­wood (Cor­nus), north­ern ar­row­wood (Vibur­num recog­ni­tum), north­ern bay­berry (Myrica pen­syl­van­ica), and south­ern mag­no­lia (Mag­no­lia gran­di­flora). (Cim­prich, et al., 2000)

• Primary Diet
• carnivore
  • insectivore

• Animal Foods
• insects
• terrestrial non-insect arthropods
• mollusks

• Plant Foods
• fruit

Pre­da­tion

Adult Vireo oli­vaceus are oc­ca­sion­ally preyed upon by sharp-shinned hawks. Eggs and nestlings are sig­nif­i­cantly more vul­ner­a­ble than adults and are pre­dated by many species in­clud­ing Amer­i­can crows, blue jays, com­mon grack­les, east­ern chip­munks, and red squir­rels. Red-eyed vireos em­ploy ag­gres­sive swoop­ing and peck­ing to deter preda­tors. Some in­cu­bat­ing fe­males crouch into the nest, re­main mo­tion­less, and rely on their olive col­oration as cam­ou­flage. Both males and fe­males pro­duce cat­bird-like mews or "myaahs" when in­trud­ers near their nests. (Cim­prich, et al., 2000)

• Anti-predator Adaptations
• cryptic

• Known Predators

  • sharp-shinned hawks (Accipiter striatus)
  • American crows (Corvus corvus)
  • blue jays (Cyanocitta cristata)
  • common grackles (Quiscalus quiscula)
  • eastern chipmunks (Tamias striatus)
  • red squirrels (Tamiasciurus hudsonicus)

Ecosys­tem Roles

As pri­mar­ily in­sec­ti­vores, Vireo oli­vaceus im­pact the in­sect pop­u­la­tions they prey upon. Adults, young, and eggs may all be preyed upon and may sup­port local preda­tors. Red-eyed vireos also serve as hosts to par­a­sites such as pro­to­zoan blood par­a­sites, feather lice, mites, and hip­po­boscid flies. Red-eyed vireo nests are often par­a­sitized by brown-headed cow­birds, usu­ally re­sult­ing in nest fail­ure. Vireos have on oc­ca­sion buried the cow­bird eggs and built a new nest over top, but this be­hav­ior is rare. (Cim­prich, et al., 2000; Ehrlich, et al., 1988)

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

To some ex­tent, Vireo oli­vaceus con­trols in­sect pest pop­u­la­tions through it's in­sec­tiv­o­rous diet. Red-eyed vireos pro­vide lit­tle eco­nomic ben­e­fit to hu­mans.

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

There are no known ad­verse ef­fects of Vireo oli­vaceus on hu­mans.

Con­ser­va­tion Sta­tus

Cur­rently, Vireo oli­vaceus pop­u­la­tions are sta­ble and dis­trib­uted across a wide ge­o­graphic range. For these rea­sons, they are of least con­cern to con­ser­va­tion or­ga­ni­za­tions. As mi­gra­tory birds, red-eyed vireos are pro­tected under the United States Mi­gra­tory Bird Act. Al­though these birds are cur­rently abun­dant and can tol­er­ate low lev­els of habi­tat de­struc­tion, large-scale habi­tat changes can re­sult in local ex­tinc­tions. Red-eyed vireos have been shown to tol­er­ate se­lec­tive har­vest­ing or small areas of clear-cut­ting that only cause small canopy open­ings. Any ac­tiv­ity that sig­nif­i­cantly re­duces canopy cover (ex­ten­sive clear-cut­ting, strip min­ing, cul­ti­vat­ing) can cause red-eyed vireos to aban­don the area for 20 to 30 years. If these ac­tiv­i­ties must occur, ef­forts should be made to leave ad­e­quate canopy cover and find a bal­ance be­tween human re­source use and en­vi­ron­men­tal pro­tec­tion. (Cim­prich, et al., 2000)

• 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

Rachelle Ster­ling (au­thor), Spe­cial Pro­jects, Tanya Dewey (ed­i­tor), Uni­ver­sity of Michi­gan-Ann Arbor.

Ref­er­ences

2007. "Whatbird.​com:​ Field Guide to Birds of North Amer­ica" (On-line). Red-eyed Vireo. Ac­cessed March 17, 2011 at http://​identify.​whatbird.​com/​obj/​573/_/​Red-eyed_​Vireo.​aspx.

Cim­prich, D., F. Moore, M. Guil­foyle. 2000. "The Birds of North Amer­ica On­line" (On-line). Red-eyed Vireo (Vireo oli­vaceus). Ac­cessed March 16, 2011 at http://​bna.​birds.​cornell.​edu/​bna/​species/​527.

Dun­ford, W., D. Burke, E. Nol. 2002. As­sess­ing edge avoid­ance and area sen­si­tiv­ity of red-eyed vireos in South­cen­tral On­tario. The Wil­son Bul­letin, 114/1: 79.

Ehrlich, P., D. Dobkin, D. Wheye. 1988. The Birder's Hand­book. New York: Simon and Schus­ter.

Klimkiewicz, M., R. Clapp, A. Futcher. 1983. Longevity records of North Amer­i­can birds: Rem­izidae through Paruli­nae. Jour­nal of Field Or­nithol­ogy, 54/3: 287-294.

Nolan, V. 1962. The sway­ing dis­play of the Red-eyed and other Vireos. The Con­dor, 64: 273 - 276.

Noon, B., J. Sauer. 1992. Pop­u­la­tions mod­els for passer­ine birds: Struc­ture, Pa­ra­me­ter­i­za­tion, and Analy­sis. Pp. 441–464 in D Mc­Cul­lough, R Bar­rett, eds. Wildlife 2001: Pop­u­la­tions. New York, New York: El­se­vier Ap­plied Sci­ences. Ac­cessed March 17, 2011 at http://​gis.​fs.​fed.​us/​psw/​publications/​noon/​noon8.​pdf.

Sib­ley, D. 2000. The Sib­ley Guide to Birds. New York: Al­fred A. Knopf.

Siepiel­ski, A., A. Rode­wald, R. Yah­ner. 2001. Nest site se­lec­tion and nest­ing suc­cess of the Red-eyed Vireo in Cen­tral Penn­syl­va­nia. The Wil­son Bul­letin, 113/3: 302.