The Yellow-throated Vireo (Vireo flavifrons) is a small songbird found in forests across much of eastern and central North America. These brightly colored birds have yellow throats and bellies, olive-green upperparts, and white spectacles around their eyes. Yellow-throated Vireos are migratory, breeding in deciduous and mixed forests across the eastern United States and Canada before traveling to wintering grounds in the tropics. In this article, we’ll look at the range and distribution of the Yellow-throated Vireo across its breeding, migrating, and wintering grounds.
Breeding Range
The Yellow-throated Vireo breeds across much of eastern North America from southern Canada south to the Gulf Coast and west to the Great Plains. Its breeding range extends:
Canada
In Canada, Yellow-throated Vireos breed locally in southern Ontario and Quebec, with isolated populations along the eastern slopes of the Rocky Mountains in Alberta.
United States
In the United States, Yellow-throated Vireos breed in:
- New England south to northern New Jersey
- Western New York state
- Western Pennsylvania
- West Virginia and western Maryland
- Eastern Kentucky and Tennessee
- North Carolina
- Northern Georgia
- Eastern Texas
- Oklahoma and eastern Kansas
- Missouri
- Arkansas
- Louisiana
- Mississippi
- Alabama
- Northern Florida
Within these states, Yellow-throated Vireos breed primarily in mature deciduous or mixed forests, especially those with tall trees. They favor forests with some openings and dense understory vegetation. In the northeast, they are often found in beech-maple forests. Farther south, they occur in oak-hickory and oak-pine woodlands. Western populations inhabit aspen groves and open pine-oak forests.
Across most of its range, the Yellow-throated Vireo is found in relatively low densities, though locally common in some areas. The highest breeding densities occur in the Ohio River Valley region.
Estimated Population in Breeding Range
Population estimates for the Yellow-throated Vireo breeding range include:
- Global breeding population:estimated at 13 million birds
- Continental population: estimated at 12 million birds
- Area of breeding range: 815,000 square miles
Based on these figures, the estimated breeding density across its range is approximately 15 birds per square mile. However, actual densities likely vary from less than 1 bird per square mile in marginal habitat to over 100 birds per square mile in prime habitat.
Migration
Yellow-throated Vireos are long-distance migrants, wintering primarily in the tropical and subtropical regions of Middle America. They migrate through the eastern half of North America at night, traveling alone or in small flocks.
Spring Migration
In spring, most Yellow-throated Vireos migrate north from March to May. They generally arrive on their breeding grounds in:
- Early May in the southern United States
- Mid-May in the northern United States and southern Canada
- Late May in northern portions of breeding range in Canada
Fall Migration
Fall migration to wintering grounds occurs earlier, from September to November. Peak fall migration occurs in:
- Early October in northern breeding regions
- Late September to mid-October in most of breeding range
- Early to mid-October in southern breeding regions
Yellow-throated Vireos are regular spring and fall migrants throughout the eastern United States. Key migration stopover sites include areas along the Appalachian Mountains and Gulf Coast.
Wintering Range
Nearly the entire global population of Yellow-throated Vireos winters in the neotropical region of Middle America, including:
Mexico
Most winter along both coasts of Mexico, as well as the Yucatan Peninsula. They are uncommon to absent in the arid interior of central Mexico.
Central America
They winter along the Caribbean slope from eastern Chiapas in Mexico south through Guatemala, Belize, Honduras, Nicaragua, Costa Rica, and western Panama.
Caribbean Islands
Yellow-throated Vireos are common winter residents on some islands, including Cuba, Grand Cayman, Cayman Brac, Jamaica, Hispaniola, Puerto Rico, and the Bahamas.
On the wintering grounds, Yellow-throated Vireos inhabit a variety of wooded habitats below 3,000 feet elevation, including tropical deciduous forest, pine-oak woodlands, mangroves, and forest edges. They tend to forage in the mid-canopy layer.
Year-Round Range
A small isolated population of Yellow-throated Vireos resides year-round on the island of Cozumel off the Yucatan Peninsula in Mexico. This is the only area where Yellow-throated Vireos are non-migratory.
The estimated population on Cozumel is 250-500 pairs. They are restricted to forests in the central and northwest regions of the island, which total around 50 square miles. At the highest density estimates, there could be up to 10 pairs per square mile on Cozumel.
Population Threats and Conservation
Overall, Yellow-throated Vireo populations are stable across most of their breeding range. However, they face some potential threats:
- Habitat loss of breeding and wintering forest habitats
- Increased brood parasitism by Brown-headed Cowbirds
- Predation by cats, raccoons, and snakes on breeding grounds
Conservation measures to protect breeding habitat and limit brood parasitism can help maintain productive populations. The year-round population on Cozumel is small and vulnerable to habitat loss and natural disasters like hurricanes. Protecting remaining forest fragments on Cozumel is important to safeguard this unique isolated population.
Region | Breeding Population Estimate |
---|---|
Global | 13 million |
Continental North America | 12 million |
Cozumel Island, Mexico | 250-500 pairs |
Conclusion
In summary, the Yellow-throated Vireo has an extensive breeding distribution across eastern North America as far north as southern Canada. Nearly the entire population migrates to winter in Mexico, Central America, and the Caribbean, with Cozumel Island being the only resident population. Loss of migratory stopover sites and breeding and wintering habitats represent the largest threats. Ongoing conservation efforts focused on habitat protection and reducing brood parasitism can help maintain stable populations of this brightly colored songbird.