Animal Diversity Web

Ge­o­graphic Range

Black­burn­ian war­blers are com­monly found through­out south­east Canada, from Al­berta into the Great Lake areas to New­found­land and into the Ap­palachi­ans as far south as Geor­gia dur­ing the sum­mer sea­son. How­ever, dur­ing mi­gra­tion, this species is seen through­out the east­ern coast of North Amer­ica and as far west as Ok­la­homa. For the most part, they mi­grate over the Gulf of Mex­ico; how­ever, some fly over the east­ern coast of Texas. Dur­ing the win­ter they can be found in Costa Rica, Panama, and into Peru. (Morse, 1994; Rap­pole, 1995)

• Biogeographic Regions
• nearctic
  • native
• neotropical
  • native

Habi­tat

Black­burn­ian war­blers in­habit de­cid­u­ous and conif­er­ous forests dur­ing the sum­mer. They pre­fer conif­er­ous forests, but will be found in spruce trees or hem­lock in de­cid­u­ous forests. In any for­est type in their sum­mer range, black­burn­ian war­blers are most ac­tive for­ag­ing and vo­cal­iz­ing in conifers. Tree species pre­ferred by black­burn­ian war­blers are pines Pinus, spruces Picea, and hem­locks Tsuga. They pre­fer the upper third of tree canopies in dense, ma­ture forests. Dur­ing the win­ter they are found in wet forests from Panama into South Amer­ica. (Green­berg, 1979; Lawrence, 1953; Morse, 1994; Young, et al., 2005; Zerda Lerner and Stauf­fer, 1998)

• Habitat Regions
• temperate
• tropical
• terrestrial

• Terrestrial Biomes
• taiga
• forest
• rainforest

Phys­i­cal De­scrip­tion

Male black­burn­ian war­blers are eas­ily iden­ti­fied by their or­ange throat, breast and fore­head. They have a black crown and cheeks and are noted for their wing bars and tail spots. Black­burn­ian war­blers have white bars on a black back, wings, and tail. There are black streaks on a white back­ground on the sides and flanks. The lower breast and stom­ach is slightly or­ange, fad­ing to white to­wards the tail.

Fe­males have a pale or­ange to yel­low faces and breasts, with brown­ish crowns, cheeks, and wings. There are two bars of white on the wings. Fe­males also have white bel­lies and un­der­tail coverts with gray­ish streaks on her sides and flanks.

Black­burn­ian war­blers are, on av­er­age, 13 cm in length with a wingspan of 21 cm. Like most war­blers, they have small, flat­tened, and short bills, and have thin, black legs with 3 toes in front and one in back (Sib­ley, 2001). (Morse, 1994; Sib­ley, et al., 2001)

• Other Physical Features
• endothermic
• homoiothermic
• bilateral symmetry

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

• Range mass

  9 to 12 g

  0.32 to 0.42 oz

• Range length

  9.5 to 19 cm

  3.74 to 7.48 in

• Average length

  13 cm

  5.12 in

• Average wingspan

  21 cm

  8.27 in

Re­pro­duc­tion

Male black­burn­ian war­blers at­tract their mates by singing in tree tops. When a po­ten­tial mate comes close, males flick their tail and peck at the branch. Males de­fend their mate from other males by flick­ing their tail, peck­ing at branches, and oc­ca­sion­ally fight­ing. Black­burn­ian war­blers, like other song­birds, are so­cially monog­a­mous. Males typ­i­cally help raise and feed the young. In some cases they have been ab­sent, likely due to oc­ca­sional ex­tra-pair cop­u­la­tions. (Lawrence, 1953; Nice, 1926)

• Mating System
• monogamous

Black­burn­ian war­blers typ­i­cally nest in the higher canopy of the tallest trees. Their nest usu­ally con­sists of twigs at­tached by spi­der silk, dry spruce twigs and bark, the in­side con­sists of dead pine nee­dles and grasses in the shape of a fine cup po­si­tioned away from the trunk and hid­den in the fo­liage on the hor­i­zon­tal branches. Fe­males are the pri­mary builders and will take 3 to 6 days to build nests. They start build­ing nests close to the time they lay eggs. They typ­i­cally breed be­tween May and July, with 1 brood per year of 4 to 5 eggs. The eggs hatch in about 2 weeks and the young fledge be­tween 2 and 4 weeks. Fe­males are usu­ally in their sec­ond year of life be­fore breed­ing. Males have been known to breed while they are still subadults (less than 1 year old), but are more suc­cess­ful and more likely to breed in their sec­ond year of life. Males help feed fe­males while in­cu­bat­ing eggs. How­ever, she will spend some time off of the nest. (Lawrence, 1953; Nice, 1926)

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

• Breeding interval

  Blackburnian warblers breed once yearly.

• Breeding season

  Blackburnian warblers breed from May to July.

• Range eggs per season

  2 to 4

• Average eggs per season

  4

• Average time to hatching

  2 weeks

• Range fledging age

  2 to 4 weeks

• Average time to independence

  2-3 months

• Average age at sexual or reproductive maturity (female)

  2 years

• Range age at sexual or reproductive maturity (male)

  1 to 2 years

• Average age at sexual or reproductive maturity (male)

  2 years

Black­burn­ian war­blers spend, on av­er­age, 22 min­utes on the nest and 5 min­utes off the nest after the eggs hatch. Both males and fe­males feed the young, fe­males more so than males. Males feed more than one hatch­ling at a time and fe­males typ­i­cally only feed one young at a time. They feed the young every 10 to 20 min­utes. They take 2 to 4 weeks until the young fledge, both par­ents care for the young dur­ing that time. It takes sev­eral months be­fore the young are in­de­pen­dent of the par­ents. (Lawrence, 1953; Morse, 1994; Nice, 1926)

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

Lifes­pan/Longevity

Black­burn­ian war­blers live in the wild for a av­er­age of 3 to 6 years. The pri­mary cause of death is not sur­viv­ing through mi­gra­tion. Be­cause of poor weather or in­suf­fi­cient en­ergy stores, death is more com­mon dur­ing spring mi­gra­tion, es­pe­cially when fly­ing over the Gulf of Mex­ico. Black­burn­ian war­blers are not kept in cap­tiv­ity. (Dunn and Gar­rett, 1997; El­ph­ick, et al., 2001; Morse, 1994; "Ref­er­ence Atlas to the Birds of North Amer­ica", 2003)

• Range lifespan
  Status: wild

  8 (high) years

• Typical lifespan
  Status: wild

  3 to 6 years

Be­hav­ior

Black­burn­ian war­blers usu­ally fly in mixed-species flocks. Typ­i­cally there are 1 to 2 black­burn­ian war­blers per flock, but there can be as many as 7. They are not very so­cial with each other or other species other than for­ag­ing near each other. They have learned to co-ex­ist with other species and avoid di­rect com­pe­ti­tion by stay­ing in the upper third of the tree canopy and for­ag­ing and nest­ing on the out­side of the branches, a form of niche par­ti­tion­ing. Even in the same habi­tats and with sim­i­lar food sources, dif­fer­ent species of the Den­droica are able to sur­vive in sep­a­rate niches. (Lawrence, 1953; MacArthur, 1958; Morse, 1994)

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

• Average territory size

  14000 m^2

Home Range

Black­burn­ian war­blers typ­i­cally live in a 0.4 to 1.1 hectare area. How­ever, they live on small is­lands if there are tall, ma­ture trees and suit­able food sources. (Morse, 1967; Morse, 1994)

Com­mu­ni­ca­tion and Per­cep­tion

Black­burn­ian war­blers sing at dusk and dawn in the fre­quency range of 4 to 12 KHz. They typ­i­cally sing the same song at both times. Males duet dur­ing these times and sing at each other after hos­tile en­coun­ters with other males. Males are usu­ally sta­tion­ary, perched higher in tree than fe­males when singing. Singing is used to ad­ver­tise for breed­ing and to ad­ver­tise ter­ri­to­ries. They have two dis­tinct song types, oc­ca­sion­ally al­ter­nat­ing them dur­ing breed­ing sea­son. They flick their tail and peck at branches while singing dur­ing breed­ing sea­son. Black­burn­ian war­blers sing one song while sta­tion­ary at the top of the tree and dur­ing en­coun­ters with other males. They chirp twice fre­quently through­out ag­gres­sive en­coun­ters with other males. The other song is pri­mar­ily used while for­ag­ing and while in the pres­ence of a fe­male. Black­burn­ian war­blers who do not find mates sing the sec­ond song type for long pe­ri­ods of time. (Morse, 1967; Morse, 1989)

• Communication Channels
• visual
• tactile
• acoustic

• Perception Channels
• visual
• tactile
• acoustic
• chemical

Food Habits

Black­burn­ian war­blers are in­sec­tiv­o­rous, di­ur­nal for­agers, usu­ally glean­ing in­sects from leaves. They also hover to cap­ture in­sects from the bot­tom of leaves. They feed on cater­pil­lars, mayflies, mos­qui­tos, gnats, spi­ders, and other small in­ver­te­brates. (Craw­ford and Jen­nings, 1989; Lawrence, 1953; Morse, 1994)

• Primary Diet
• carnivore
  • insectivore

• Animal Foods
• insects
• terrestrial non-insect arthropods

Pre­da­tion

Black­burn­ian war­blers are typ­i­cally preyed on by larger birds of prey and some mam­mals. Most pre­da­tion is on eggs, hatch­lings, and fledg­lings, or on adults as they watch and de­fend nests. Hawks are the most com­mon preda­tors. (Lawrence, 1953; Morse, 1994)

• Known Predators

  • sharp-shinned hawks (Accipiter striatus)
  • Cooper's hawks (Accipiter cooperii)
  • red squirrels (Tamiasciurus hudsonicus)
  • blue jays (Cyanocitta cristata)

Ecosys­tem Roles

Black­burn­ian war­blers are known for their in­creased pres­ence dur­ing spruce bud­worm (Cho­ri­s­toneura species) break­outs, in which their sur­vival and re­pro­duc­tion are greater be­cause of the abun­dance of prey. These war­blers are also well-known for in­ter­spe­cific niche par­ti­tion­ing. Which is how they avoid di­rect com­pe­ti­tion with species of the same genus; they co­ex­ist by using dif­fer­ent parts of the same tree for nest­ing and for­ag­ing.

Black­burn­ian war­blers are used as hosts by mites and lice. (Betts, et al., 2006; Betts, et al., 2007; Craw­ford and Jen­nings, 1989; Morse, 1994; Pe­ters, 1936; Schulte, et al., 2005; Zerda Lerner and Stauf­fer, 1998)

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Black­burn­ian war­blers are strong in­di­ca­tors of mixed de­cid­u­ous-conif­er­ous forests and undis­turbed, ma­ture conif­er­ous forests. Sur­vey­ors use this species to study the ecol­ogy and ef­fect of for­est frag­men­ta­tion by tim­ber har­vest­ing. They are also im­por­tant for con­trol­ling spruce bud­worm (Cho­ri­s­toneura species) out­breaks. (Betts, et al., 2006; Betts, et al., 2007; Craw­ford and Jen­nings, 1989; Schulte, et al., 2005; Zerda Lerner and Stauf­fer, 1998)

• Positive Impacts
• controls pest population

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

There is no known neg­a­tive im­pact of black­burn­ian war­blers on hu­mans.

Con­ser­va­tion Sta­tus

Cur­rently, black­burn­ian war­bler pop­u­la­tions are not con­sid­ered threat­ened. How­ever, win­ter­ing habi­tats are rapidly de­clin­ing and they are sen­si­tive to for­est frag­men­ta­tion. (Morse, 1994)

• 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

Reese Clark (au­thor), Rad­ford Uni­ver­sity, Rachelle Ster­ling (ed­i­tor), Spe­cial Pro­jects, Karen Pow­ers (ed­i­tor), Rad­ford Uni­ver­sity, Tanya Dewey (ed­i­tor), Uni­ver­sity of Michi­gan-Ann Arbor.

Ref­er­ences

Na­tional Ge­o­graphic So­ci­ety. 2003. Ref­er­ence Atlas to the Birds of North Amer­ica. Wash­ing­ton D.C.: Na­tional Ge­o­graphic So­ci­ety.

Betts, M., D. Mitchell, A. Di­a­mond, J. Bêty. 2007. Un­even Rates of Land­scape Change as a Source of Bias in Road­side Wildlife Sur­veys. Jour­nal of Wildlife Man­age­ment, 71: 2266-2273.

Betts, M., B. Zitske, A. Hadley, A. Di­a­mond. 2006. Mi­grant For­est Song­birds Un­der­take Breed­ing Dis­per­sal Fol­low­ing Tim­ber Har­vest. North­east­ern Nat­u­ral­ist, 13: 531-536.

Craw­ford, H., D. Jen­nings. 1989. Pre­da­tion by Birds on Spruce Bud­worm Cho­ri­s­toneura Fu­mifer­ana: Func­tional, Nu­mer­i­cal, and Total Re­sponses. Ecol­ogy, 70: 152-163.

Dunn, J., K. Gar­rett. 1997. A Field Guide to War­blers of North Amer­ica. New York, NY: Houghton Mif­flin Com­pany.

El­ph­ick, C., J. Dun­ning, D. Sib­ley. 2001. The Sib­ley Guide to Bird Life and Be­hav­ior. New York: Al­fred A Knopf.

Green­berg, R. 1979. Body Size, Breed­ing Habi­tat, and Win­ter Ex­ploita­tion Sys­tems in Den­droica. The Auk, 96: 756-766.

Kendeigh, C. 1945. Nest­ing be­hav­iors of Wood War­blers. The Wil­son Bul­letin, Vol. 57, No. 3: 145-164.

Lawrence, L. 1953. Notes on the Nest­ing Be­hav­ior of the Black­burn­ian War­bler. The Wil­son Bul­letin, 65: 135-144.

MacArthur, R. 1958. Pop­u­la­tion Ecol­ogy of Some War­blers of North­east­ern Conif­er­ous Forests. Ecol­ogy, Vol. 39, No. 4: 599-619.

Morse, D. 1994. Black­burn­ian War­bler (Den­droica fusca). The Birds of North Amer­ica, 102: 583.

Morse, D. 1989. Song Pat­terns of War­blers at Dawn and Dusk. The Wil­son Bul­letin, 101: 26-35.

Morse, D. 1967. The Con­texts of Songs in Black-Throated Green and Black­burn­ian War­blers. The Wil­son Bul­letin, 79: 64-74.

Nice, M. 1926. Be­hav­ior of Black­burn­ian, Myr­tle, and Black-Throated Blue War­blers, with Young. The Wil­son Bul­letin, 38: 82-83.

Pe­ters, H. 1936. A list of ex­ter­nal par­a­sites from birds of the east­ern part of the United States. Bird-Band­ing, Vol. 7, No. 1: 9-27.

Rap­pole, J. 1995. The Ecol­ogy of Mi­grant Birds: A neotrop­i­cal Per­spec­tive. Wash­ing­ton and Lon­don: Smith­son­ian In­sti­tu­tion Press.

Schulte, L., A. Pid­geon, D. Mlade­noff. 2005. One Hun­dred Fifty Years of Change in For­est Bird Breed­ing Habi­tat: Es­ti­mates of Species Dis­tri­b­u­tion. Con­ser­va­tion Bi­ol­ogy, 19: 1944-1956.

Sib­ley, D., J. Dun­ning, Jr, C. El­ph­ick. 2001. The Sib­ley Guide to Bird Life & Be­hav­ior. New York: Al­fred A. Knopf, Inc..

Veneir, L., D. McKen­ney, Y. Wang, J. McKee. 1999. Mod­els of large-scale breed­ing-bird dis­tri­b­u­tion as a func­tion of macro-cli­mate in On­tario, Canada. Jour­nal of Bio­geog­ra­phy, 26: 315-328.

Young, L., M. Betts, A. Di­a­mond. 2005. Do Black­burn­ian War­blers se­lect mixed forests? The im­por­tance of spa­tial res­o­lu­tion in defin­ing habi­tat. For­est Ecol­ogy and Man­age­ment, 214: 358-372.

Zerda Lerner, S., D. Stauf­fer. 1998. Habi­tat Se­lec­tion by Black­burn­ian War­blers Win­ter­ing in Colom­bia. Jour­nal of Field Or­nithol­ogy, 69: 457-465.