Animal Diversity Web

Ge­o­graphic Range

The Mag­no­lia War­bler, dur­ing breed­ing sea­son, is found in cen­tral and south­ern Canada, down into the north­ern United States, such as in Michi­gan, Wis­con­sin, and Min­nesota. The war­blers are com­monly found in both the Ap­palachian Moun­tains as well as in the New Eng­land re­gion, ap­prox­i­mately as far south as North Car­olina. In the win­ter how­ever, the Mag­no­lia War­bler mi­grates south, win­ter­ing from Mex­ico to Panama. It is oc­ca­sion­ally found in the West In­dies, the west­ern and south­ern United States. (Cor­nell Lab­o­ra­tory of Or­nithol­ogy, 2001; Cur­son, 1994; Griscom and Sprunt Jr., 1979)

• Biogeographic Regions
• nearctic
  • native
• neotropical
  • native

Habi­tat

The name of the Mag­no­lia War­bler is mis­lead­ing be­cause it is ac­tu­ally rarely found in Mag­no­lia trees. It was named by Alexan­der Wil­son who hap­pened to see one of these birds in a mag­no­lia tree in the South, on its an­nual mi­gra­tion. The Mag­no­lia War­bler is in­stead found in damp conif­er­ous forests, which in­clude trees like pine, red maple, spruce, hem­locks, and bal­sam firs. It tends to dwell in the lower parts of the trees.

(Kauf­man, 1996; Alsop, 2001; Har­ri­son, 1984; Griscom & Sprunt, 1979)

• Habitat Regions
• temperate
• tropical
• terrestrial

• Terrestrial Biomes
• forest

Phys­i­cal De­scrip­tion

The Mag­no­lia War­bler is eas­ily rec­og­niz­able due to its dis­tinc­tive yel­low and black col­or­ing. Its tail is black at the tip with large white spots which make up a band in the mid­dle. The rump and most of its un­der­parts of the Mag­no­lia War­bler are yel­low. It also has black streaks on its breast. Breed­ing males have a black face as well. Fe­males are sim­i­lar ex­cept that they also have more white on their wings as well as grey on their heads. Their col­ors tend to be a bit duller, and their pat­terns less dis­tinct than those of the males. Ju­ve­nile Mag­no­lia War­blers also tend to be duller in color, with more grey than black, as well as hav­ing some brown or olive col­or­ing on the body. They also may have white bands around their eyes. The spe­cific col­oration pat­terns of the Mag­no­lia War­bler varies greatly de­pend­ing on the stage of life it is in (breed­ing or not-breed­ing, adult, ju­ve­nile, or first-year, male or fe­male, etc.)

(Kulba & Re­ich­wein, Date Un­known; Cur­son, 1994; Alsop, 2001)

• Other Physical Features
• endothermic
• bilateral symmetry

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

• Range mass

  6.6 to 12.6 g

  0.23 to 0.44 oz

• Average mass

  8 g

  0.28 oz

• Range length

  12 to 13 cm

  4.72 to 5.12 in

• Average wingspan

  19.68 cm

  7.75 in

Re­pro­duc­tion

The Mag­no­lia War­bler is monog­a­mous. Dur­ing breed­ing sea­son, the males grow very com­pet­i­tive and try to im­press the fe­males by show­ing off their dis­tinc­tive col­or­ing. The males also can get vi­o­lent with each other at this time, fight­ing one an­other with their beaks and wings. Males also tend to sing cheer­ful tunes to the fe­male they have cho­sen to mate with. (Alsop, 2001; Bent, 1953)

• Mating System
• monogamous

Mag­no­lia War­blers cre­ate their nests in low tree branches or twigs, usu­ally in the most dense areas of the for­est. They seem to build rather messy nests, which are put to­gether very care­lessly, and are not very sta­ble or se­cure. They are made up of twigs, weeds, hay, and grass.

The fe­male Mag­no­lia War­bler lays from 3-5 eggs at a time and they lay their eggs once a year. The eggs are white, creamy white, or some­times green­ish white. They are speck­led with brown spots or splotches which can range from very dark to very light and very few to very many. The eggs are slightly glossy. They mea­sure, on av­er­age, 16.3 by 12.3 mil­lime­ters. In­cu­ba­tion lasts 11 to 13 days.

After a chick hatches, its eyes open after about 3 or 4 days. The feath­ers be­come well de­vel­oped after only about 8 or 9 days. This is also about the same time they first leave the nest and begin to find their own food. (Cur­son, 1994; Kauf­man, 1996; Bent, 1953)

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

• Breeding season

  May-June

• Range eggs per season

  3 to 5

• Average eggs per season

  4

  AnAge

• Range time to hatching

  11 to 13 days

• Range fledging age

  8 to 10 days

Fe­males in­cu­bate the eggs and have a more ac­tive role in the rais­ing of the young birds, but both the male and the fe­male sup­ply food to the young. Even after they fledge, baby birds re­main close to one an­other and to their par­ents for about a month af­ter­ward. Dur­ing this time, the par­ents con­tinue to pro­vide food for the young, how­ever after this time they are on their own. (Bent, 1953; Alsop, 2001)

• Parental Investment
• altricial
• male parental care
• female parental care

Lifes­pan/Longevity

The max­i­mum lifes­pan of the Mag­no­lia War­bler is recorded at 6 years and 11 months.

(Klimkiewicz, 2002)

• Range lifespan
  Status: wild

  7 (high) years

• Average lifespan
  Status: wild

  96 months

  Bird Banding Laboratory

Be­hav­ior

The Mag­no­lia War­bler is usu­ally found liv­ing by it­self or in pairs. It is some­times ter­ri­to­r­ial in the win­ter months. It is usu­ally rather easy to watch, be­cause it lives so low in the for­est, and also doesn't seem to be very shy, un­less it is pro­tec­tively guard­ing its young. It is quite ac­tive, and en­er­getic, hop­ping and fly­ing from branch to branch. It does not seem to mind at­ten­tion as it sings al­most con­stantly and often ap­pears to be show­ing off its tail feath­ers, by spread­ing them or flick­ing them. Al­though they usu­ally live alone, they don't seem to show any hos­til­ity to­ward other birds, of other species or their own.

(Alsop, 2001;Bent, 1953;Cur­son, 1994)

• Key Behaviors
• flies
• motile
• migratory
• solitary
• territorial

Com­mu­ni­ca­tion and Per­cep­tion

• Communication Channels
• visual
• acoustic

• Perception Channels
• visual
• tactile
• acoustic
• chemical

Food Habits

The Mag­no­lia War­bler feeds al­most ex­clu­sively on in­sects. It for­ages for its food in the lower or mid­dle branches of the trees. It picks in­sects off of tree nee­dles, leaves, and twigs, as well as some­times from the un­der­sides of plants and under the bark of trees. Some­times it will also hover to search for food and fly short dis­tances to catch its prey. Dur­ing bad weather, when in­sects can be hard to find, the Mag­no­lia War­bler will also feed on berries.

Foods eaten in­clude: bee­tles, moth cater­pil­lars, leafhop­pers, aphids, spi­ders, worms, flies, plant lice and berries.

(Kauf­man, 1996; Cur­son, 1994; Griscom & Sprunt, 1979)

• Primary Diet
• carnivore
  • insectivore

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

• Plant Foods
• fruit

Pre­da­tion

The Mag­no­lia War­bler takes great care to hide its nest deep within the dense growth of the for­est, in order to pro­tect its eggs from preda­tors. Cow­birds lay their eggs in Mag­no­lia War­bler nests and the young cow­birds may eject eggs or young of their hosts. Hawks are known egg and young preda­tors (Har­ri­son, 1984; Bent, 1953)

• Known Predators

  • cowbirds (Molothrus)
  • hawks (Accipitridae)

Ecosys­tem Roles

The Mag­no­lia War­bler eats in­sects which are harm­ful to wood­land trees, such as plant lice, leaf hop­pers, and bee­tles. The Mag­no­lia War­bler also oc­ca­sion­ally acts as a host species to the par­a­sitic cow­bird, which steals eggs and food from the war­bler.

(Bent, 1953; Har­ri­son, 1984)

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

The Mag­no­lia War­bler eats many in­sects such as moth cater­pil­lars, aphids, and plant lice which can be prob­lems for hu­mans.

(Griscom & Sprunt, 1979; Kauf­man, 1996)

• Positive Impacts
• controls pest population

Con­ser­va­tion Sta­tus

There have been ac­counts of both an in­crease and de­cline in the num­ber of Mag­no­lia War­blers. How­ever it is im­por­tant to note that the Mag­no­lia War­bler is quite vul­ner­a­ble to a loss of habi­tat. As many east­ern spruce and fir forests are de­clin­ing, due mostly to air pol­lu­tion, the pop­u­la­tion of Mag­no­lia War­blers is also likely to de­cline.

(Alsop, 2001)

• 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

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

Ref­er­ences

Alsop III, F. 2001. Birds of North Amer­ica: West­ern Re­gion. New York: DK Pub­lish­ing.

Bent, A. 1953. Life His­to­ries of North Amer­i­can Wood War­blers. Wash­ing­ton D.C.: Smith­son­ian In­sti­tu­tion.

Cor­nell Lab­o­ra­tory of Or­nithol­ogy, 2001. "Mag­no­lia War­bler" (On-line). Ac­cessed March 20, 2002 at http://​birds.​cornell.​edu/​BOW/​magwar/​.

Cur­son, J. 1994. New World War­blers. Lon­don: Christo­pher Helm Pub­lish­ers.

Griscom, L., A. Sprunt Jr.. 1979. The War­blers of Amer­ica. New York: Dou­ble­day.

Har­ri­son, H. 1984. Wood War­blers' World. New York: Simon and Schus­ter.

Kauf­man, K. 1996. Lives of North Amer­i­can Birds. New York: Houghton Mif­flin Co..

Klimkiewicz, M. 2002. "Longevity Records of North Amer­i­can Birds Ver­sion 2002.1. Pau­tux­ent Wildlife Re­search Cen­ter. Bird Band­ing Lab­o­ra­tory. Lau­rel MD." (On-line). Ac­cessed March 22, 2002. at http://​www.​pwrc.​usgs.​gov/​bbl/​homepage/​longvrec.​htm.

Kulba, B., P. Re­ich­wein. "War­blers of Canada" (On-line). Ac­cessed March 20, 2002 at http://​collections.​ic.​gc.​ca/​warblers/​species/​mnwa.​htm.

Tufts, R. 1986. "Birds of Nova Sco­tia" (On-line). Ac­cessed March 20, 2002 at http://​museum.​gov.​ns.​ca/​mnh/​nature/​nsbirds/​bns0316.​htm.