Common Yellowthroat

(Geothlypis trichas)

BY:

Kendrick Weeks and Mark Johns, NC Wildlife Resources Commission

Photo by Ed Erkes

Common Yellowthroat (Geothlypis trichas)

The scientific name translates to “small thrush-like bird of the Earth”; however, this bird is a warbler. The common yellowthroat is a species of dense, low shrubby vegetation. Partners in Flight does not consider this a species of high conservation concern.

Description

Common Yellowthroats are sexually dimorphic and the male is the only yellow warbler with a solid, black mask. Both male and female have olive upperparts and yellow and white underparts, but females usually have no mask and fainter, yellow underparts. This gives the female an overall drab, olive coloration. The mask of the male has an upper border of light grey or white that separates the mask from the olive on the head.

Voice

The song is usually a three-part “witch-i-ty, witch-i-ty, witch-i-ty” that advertises the male territory and attracts potential mates. A common call is a loud and abrupt “CHIT” that is often heard emanating from shrub thickets and may be a communicative warning to mates in response to predators. A similar chatter is likely given in response to territorial intruders.

Range

Common Yellowthroats are widespread breeders from eastern Alaska to Newfoundland south to Florida and central Mexico. They are only absent in the desert southwest from central Texas to central California. In North Carolina, Common Yellowthroats breed statewide but are most common along the Coastal Plain due to the abundance of shrub bog (Pocosins) and stream communities and least common in the mountains. It is less common west of the Coastal Plain mainly due to localized habitat. These warblers are migrants that winter in the Coastal Plain fringes of the southern United States and in the tropics from Hispaniola in the Caribbean west to Panama. The southern most breeding populations are considered to be short-distance migrants or sedentary populations.

Habitat and Habits

Common Yellowthroats are most common in shrub thicket wetlands where they forage, build their nests, and hide from predators. However, it is apparent that the structure and extent of shrub vegetation are the main factors for suitable habitat; Common Yellowthroats are commonly found in shrub thickets with or without a canopy of trees. Some of the most abundant populations can be found in Pocosins; shrub bogs unique to the southeastern Coastal Plain of the United States. However, other shrub thickets along streams and within wetlands and uplands will provide suitable habitat. In most uplands and some wetlands, the canopy must be open to produce suitable habitat. Many of these upland shrub habitats are often ephemeral (short lived) and must be maintained to sustain Common Yellowthroats. Early succession vegetation found in utility rights-of-way, abandoned agriculture, and regenerating clear-cuts are common upland habitats. When saplings within an upland shrub thicket get tall enough to shade and thin the shrub layer, this bird is rarely present. Early succession vegetation is consistently produced in nature by various abiotic factors (e.g., ice and snow storms, tornadoes, hurricanes, fire, and other meteorological events). Well-developed piedmont prairies on longer prescribed burning cycles also provide suitable habitat for Common Yellowthroats. Other wetlands, including some pocosins, can produce nearly impenetrable shrub thickets underneath a relatively closed canopy.

Although they are very responsive to “pishing”, they rarely leave the protective cover of the shrub thicket. However, males typically sing near the top of the shrub thicket. They are naturally skulking but very curious of movement in the shrub thicket. Common Yellowthroats forage near the ground and eat a wide range of spiders and insects, such as cankerworms and other caterpillars, flies, beetles, and nymphs.

The breeding season in North Carolina runs from May through July. Territories can range from 0.5-6 acres depending on habitat quality. Nests are typically constructed on or very close to the ground within the shrub thicket. The female incubates 1-6 (4) eggs for approximately 12 days, and both adults feed the young after hatching. After leaving the nest in about 8-10 days after hatching, the young birds will often remain with the parents for several weeks. They are mainly cared for by the male during this time.

Management Recommendations

Natural resource managers have the potential to strongly influence populations of Common Yellowthroats, as well as other shrub thicket bird species. Common Yellowthroats tend to decrease in numbers as succession continues towards the small sapling stage. They are most numerous in dense small shrubs (4 to 8 feet). Although competition from dense small shrubs can inhibit tree growth and is sometimes not encouraged beneath pine plantations (exceptions include industrial forestland in the coastal plain), bottomlands and streamside management zones can be managed mechanically or by fire at long intervals to maintain dense vegetation that will encourage Common Yellowthroats to colonize and breed. Giant cane thickets also provide suitable habitat and can be perpetuated through fire management. Otherwise, clear-cutting and selective cutting can both produce suitable habitat for Common Yellowthroats throughout North Carolina, especially in upland forests.

*Identify existing habitat before silvicultural operations (e.g., thinning, harvesting, and site preparation).

*Do not harvest forested habitat (e.g. wetlands), mow, or conduct prescribed burns from April through August.

*Exclude grazing animals from bottomland hardwood forests and riparian forests.

*Maintain shrubby vegetation along field ditches and borders by lengthening mechanical, fire, or chemical vegetation control cycles. Maintenance should not be conducted from April through August every year. Wider buffers not only provide more Common Yellowthroat habitat, but also contribute to improved water quality.

Suitable wetland habitat is often composed of pocosin species such as inkberry (Ilex glabra), fetterbush (Lyonia lucida), sweet pepperbush (Clethra alnifolia), zenobia (Zenobia pulverulenta), blueberry (Vaccinium spp.), giant cane (Arundinaria gigantea), tall fetterbush (Leucothoe racemosa), laurel greenbrier (Smilax laurifolia), and red bay (Persea borbonia). Other suitable wetland habitats include species such as black willow (Salix nigra), bulrushes (Scirpus spp.), rushes (Juncus spp.), and cattail (Typha spp.).

Suitable upland habitat is usually produced in openings composed of woody shrubs and saplings such as wax myrtle (Morella cerifera), eastern baccharis (Baccharis halimifolia) and blackberry (Rubus sp.).

SOURCES OF TECHNICAL INFORMATION ON: GEOTHLYPIS TRICHAS

Scientific Papers:

Fletcher, R.J. Jr. and R.R. Koford. 2002. Habitat and landscape associations of breeding birds in native and restored grasslands. Journal of Wildlife Management 66(4): 1011-1022.

Guzy, M. J., and G. Ritchison. 1999. Common Yellowthroat (Geothlypis trichas). In The Birds of North America, No. 448 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.

Kelly, J.P. and C. Wood. 1996. Diurnal, intraseasonal, and intersexual variation in foraging behavior of the common yellowthroat. Condor 98(3): 491-500.

Madden, E.M., A.J. Hansen, and R.K. Murphy. 1999. Influence of Prescribed Fire History on Habitat and Abundance of Passerine Birds in Northern Mixed-Grass Prairie. Canadian Field-Naturalist 113(4): 627-640.

Moorman, C.E. and D.C. Guynn Jr. 2002. Effects of group-selection opening size on breeding bird habitat use in a bottomland forest. Ecological Applications 11(6): 1680-1691.

Murray, L.D., L.B. Best, T.J. Jacobsen, and M.L. Braster. 2003. Potential effects on grassland birds of converting marginal cropland to switchgrass biomass production. Biomass and Bioenergy 25(2): 167-175.

Patterson, M.P. and L.B. Best. 1996. Bird abundance and nesting success in Iowa CRP fields: the importance of vegetation structure and composition. American Midland Naturalist 135(1):153-167.

Santillo, D.J., P.W. Brown, D.M. Leslie Jr. 1989. Response of songbirds to glyphosate-induced habitat changes on clearcuts. Journal of Wildlife Management 53(1): 64-71.

Schulte, L.A. and G.J. Niemi. 1999. Bird communities of early-successional burned and logged forest. Journal of Wildlife Management. 62(4): 1418-1429.

Thusius, K.J., K.A. Peterson, P.O. Dunn, and L.A. Whittingham. 2001. Male mask size is correlated with mating success in the common yellowthroat. Animal Behaviour 62(3): 435-446.

Twedt, D.J., R.R. Wilson, J.L. Henne-Kerr, and R.B. Hamilton. 1999. Impact of forest type and management strategy on avian densities in the Mississippi Alluvial Valley, USA. Forest Ecology and Management 123(2-3): 261-274.

Van Dyke, F., S.E. Van Kley, C.E. Page, and J.G. Van Beek. 2004. Restoration efforts for plant and bird communities in tallgrass prairies using prescribed burning and mowing. Restoration Ecology 12(4): 575-585.

Whitehead, M.A., S.H. Schweitzer, and W. Post. 2002. Cowbird/host interactions in a southeastern old-field: A recent contact area? Journal of Field Ornithology 73(4): 379-386.

Wood, D.R., L.W. Burger Jr., J.L. Bowman, and C.L. Hardy. 2004. Avian community response to pine-grassland restoration. Wildlife Society Bulletin 32(3):819-828.

WEBSITES OF INTEREST:

Cornell Lab of Ornithology: Species Profiles

http://www.birds.cornell.edu/programs/AllAboutBirds/BirdGuide/Common_Yellowthroat_dtl.html

NatureServe

http://www.natureserve.org/explorer/servlet/NatureServe?searchName=Geothlypis+trichas

USFWS

http://www.mbr-pwrc.usgs.gov/id/framlst/i6810id.html