Seiurus noveboracensisnorthern waterthrush

Ge­o­graphic Range

In the breed­ing sea­son, the North­ern Wa­terthrush is found in a belt stretch­ing from north cen­tral Alaska, east across all of the Cana­dian provinces. In the win­ter sea­son, the species is found in the trop­i­cal man­groves of Cen­tral and South Amer­ica.

Habi­tat

The North­ern Wa­terthrush prefers cool, dark, wooded swamps, thick­ets of bogs, mar­gins of north­ern lakes, and wil­low and alder bor­dered rivers. Dur­ing the spring and fall mi­gra­tion, the bird can be found in thick cover along streams, in marshes, and by stag­nant pools.

  • Aquatic Biomes
  • lakes and ponds
  • rivers and streams

Phys­i­cal De­scrip­tion

The North­ern Wa­terthrush is a large, ground walk­ing war­bler with a brown back and a white or yel­low­ish streaked breast. The breast, sides, and flanks are streaked with a dark olive or black. There is an olive-col­ored tri­an­gu­lar spot in the front of the eye and a cres­cent shaped mark on the lower eye­lid. The throat is also cov­ered with small tri­an­gu­lar marks.

  • Average mass
    18.7 g
    0.66 oz
    AnAge
  • Average basal metabolic rate
    0.28391 W
    AnAge

Re­pro­duc­tion

Pair bond­ing be­gins im­me­di­ately after the fe­male ar­rives on the breed­ing site. Males perch in trees that are stand­ing near water while fe­males are below usu­ally feed­ing along the edge of the water. Males vi­brate their wings and raise their crown feath­ers and sing. The fe­male may an­swer with a chink. The pair bond is bro­ken shortly after suc­cess­ful fledg­ing. The male se­lects the gen­eral area of the nest­ing site, but the fe­male chooses the ac­tual nest site. Nests are usu­ally in the cav­ity of a root sys­tem of wind-blown trees in a wooded swamp, on the side of a fern clump or under cover along the banks of a lake or a river. There is typ­i­cally cov­er­ing above the nest and an open­ing to one side. The ex­te­rior of the nest is mainly moss and liv­er­wort ga­me­to­phytes. The in­te­rior of the nest cup is con­structed with grass stems, twigs, or pine nee­dles, and then lined with the hair of deer, cari­bou, cow, and rab­bit. Av­er­age clutch is com­posed of four white ovate eggs spot­ted with browns and greys. The fe­male is solely re­spon­si­ble for in­cu­ba­tion, which lasts 12 days. Both par­ents, how­ever, share feed­ing re­spon­si­bil­i­ties. After four to five weeks the chicks begin feed­ing them­selves.

  • Average eggs per season
    4
    AnAge

Lifes­pan/Longevity

Be­hav­ior

The North­ern Wa­terthrush is soli­tary be­fore pair for­ma­tion, then forms fam­ily groups after the young de­part from the nest. The bird is an an­nual mi­grant to the West In­dies and Cen­tral and South Amer­ica. Mi­gra­tions are made in loosely as­so­ci­ated flocks that fly at night. The bird is sel­dom agres­sive to­wards other species; how­ever, it has a strong re­ac­tion to the song of the Kirt­land's War­bler.

Com­mu­ni­ca­tion and Per­cep­tion

Food Habits

Dur­ing the breed­ing sea­son, the basic diet con­sists of lar­val and adult in­sects, spi­ders, and snails. After leaf emer­gence in the spring, the bird feeds on pri­mar­ily on but­ter­fly lar­vae. On the win­ter grounds, the bird con­sumes a greater va­ri­ety of food, adding min­nows and de­ca­pod crus­taceans to its diet. The North­ern Wa­terthrush for­ages alone using such tac­tics as twig glean­ing, fly­catch­ing, hov­er­ing, chas­ing, and a lot of peck­ing. Mi­cro­hab­i­tats for for­ag­ing in­clude water, ground, foilage, and air. Be­fore leaf emer­gence, the Wa­terthrush typ­i­cally spends about 75% of the time feed­ing in water, al­ter­nat­ing be­tween wad­ing and walk­ing along logs, on branches, and the water's edge.

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Feed on in­sects that are re­garded as pests to hu­mans.

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

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Con­ser­va­tion Sta­tus

Degra­da­tion of habi­tat and pes­ti­cides are the biggest threats fac­ing the species. North­ern Wa­terthrush pop­u­la­tions, how­ever, have man­aged to re­main sta­ble de­spite these threats. Drainage of swamps for agri­cul­ture and wet­land de­vel­op­ment into ponds or lakes may re­duce breed­ing habi­tat. Pes­ti­cides are also af­fect­ing the North­ern Wa­terthrush. Aer­ial spray­ing for the spruce bud­worm can kill the birds di­rectly or re­duce the bio­mass of their prey.

Other Com­ments

Most bird watch­ers only see the North­ern Wa­terthrush in back­yards, city parks, and wet places when the bird is en route to the trop­i­cal man­groves of Cen­tral and South Amer­ica

Con­trib­u­tors

Marie S. Har­ris (au­thor), Uni­ver­sity of Michi­gan-Ann Arbor.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

Neotropical

living in the southern part of the New World. In other words, Central and South America.

World Map

acoustic

uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

tactile

uses touch to communicate

visual

uses sight to communicate

Ref­er­ences

Eaton, Stephen, W.. The Birds of North Amer­ica, No. 182, 1995.