We reside in Buffalo, New York, which is most known for its Super Bowl losses and lake effect snow squalls that sweep in from Lakes Erie and Ontario. One benefit of living near the Great Lakes is that these massive bodies of water tend to halt and funnel bird migration around them. We may easily see a dozen or more kinds of warblers as they travel along the Lakes’ borders to their breeding sites in Canada on warm May days with southerly breezes. For example, on May 25, 1997, we discovered 15 warbler species at Niagara Falls, New York, including Blackburnian, Black-throated Blue, Black-throated Green, Wilson’s, Canada, Chestnut-sided, Tennessee, and Bay-breasted.
Most birders associate these species with the Eastern Wood Warbler, however several may also be found in Western North America. Yellow-rumped, Painted Redstart, Nashville, and Orange-crowned Warblers were among the species we saw on a recent March trip to Tuscon. The Orange-crowned and Painted Redstart may be found in the West in the spring and summer, with the Orange-crowned also visiting the East in the winter. The Yellow-rumped and Nashville, on the other hand, were most likely migrants going across the Sonoran Desert and locating oases in Sabine Canyon.
Indeed, where you locate warblers is partly determined by how you define East and West. We followed tradition by using the Mississippi River as the divider of North America, since it was the beginning point of Lewis and Clark’s expedition at St. Louis. Using range maps from Dunn and Garrett’s Warblers and Peterson’s North American Birds CD-ROM, we classified the 46 major North American warbler species into four categories: birds found only in the Western United States; birds found in both the Eastern and Western United States; birds found in both the Eastern and Western United States; and birds found in both the Eastern and Western United States and Western Canada. The findings are shown in the following Table.
Column 1 lists 11 species that can only be found in the Western United States. Several of these species, such as the Red-faced Warbler, Olive Warbler, and Painted Redstart, are exclusively found in Arizona and New Mexico. The Virginia’s Warbler, on the other hand, has a greater range that includes mountain sides not only in Arizona and New Mexico, but also in Idaho, Wyoming, Nevada, Utah, and Colorado.
The second column contains 17 warblers from both the Western and Eastern United States. The majority of these birds, however, only breed in a few regions west of the Mississippi. The Yellow-throated Warbler, for example, may be seen in eastern Texas, Oklahoma, and Kansas throughout the spring and summer. Similarly, American Redstarts breed in extreme eastern Nebraska, Kansas, Oklahoma, and Texas, but also in Oregon, Idaho, Montana, Utah, Colorado, North Dakota, and South Dakota, where they prefer willows, alders, birches, and aspens. The Cerulean Warbler, regarded to be North America’s fastest-declining warbler, is also included in this group. The Cerulean, a very uncommon visitor farther West, breeds in restricted regions of eastern Nebraska, Kansas, Oklahoma, and Texas, like the Redstart.
Column 3 lists nine species of warblers from Eastern and Western North America. This broad group contains birds whose Western range is essentially limited to Canada, as well as species widespread over much of North America. Orange-crowned Warblers, which spend the summer in the Northwestern United States and Northern Canada, are among the latter. Orange-crowned warblers are one of the few warbler species that spend the winter in the western and eastern United States. Orange-crowned warblers spend the winter from California through Florida, then from Mexico to Guatemala.
Finally, Column 4 includes nine species present in both the Eastern United States and Canada. These are birds that spend the summer breeding in British Columbia, Ontario, Quebec, the Maritime Provinces, and the far Northeastern United States, similar to the Bay-breasted and Tennessee warblers. The Blackpoll Warbler, the most migratory warbler, is included in this category. According to Dunn and Garrett, this little bird breeds as far north as Alaska but spends the winter east of the Andes in northern South America. We frequently hear the high-pitched singing of a Blackpoll in our backyard oaks during the final week of May when this migratory passes through our area.
The Blackpoll is one of the most common Eastern warblers seen in the West. According to Dunn and Garrett, Blackpolls have been spotted in every Western state except Idaho, with over 3,000 individuals reported in California. In the West, blackpolls have plenty of warbler company. Pick up any edition of the National Audubon Society’s Field Notes for spring and summer, and you’ll discover observations of warblers all throughout the Western United States and Canada. A Black-and-white Warbler was discovered at Camas National Wildlife Refuge; Hooded, Chestnut-sided, Blackpoll, and Tennessee Warblers were discovered on the campus of the University of British Columbia; and a Black-throated Blue Warbler was discovered within Denver International Airport. In 1997, California had 15 species of Eastern warblers, including Prothonotary, Hooded, Blue-winged, and Cape May.
So, no matter where you reside in the West, the appearance of a warbler in your backyard should not come as a surprise. The surprise (again, refer to the Table) is that no warblers can be found outside of the Eastern United States. On the other hand, 11 species are exclusively found in the West! A person residing near the junction of Wyoming, Colorado, and Utah must travel less distance to view all 46 species than someone living in the continent’s east. Perhaps the term “Eastern wood warblers” is a misnomer that should be reconsidered.
The Geography of Warblers
Western US/North America
- Black-throated Gray
- Painted Redstart
Eastern and Western Eastern US
- Louisiana Waterthrush
- American Redstart
- Northern Waterthrush
- Common Yellowthroat
- Yellow-breasted Chat
Eastern and Western North America
- Northern Parula
- Black-throated Green
Eastern US and Western Canada
- Cape May
- Black-throated Blue
Scott T. Meier, Ph.D. is a faculty member in the Department of Counseling and Educational Psychology at the State University of New York at Buffalo. He is an avid keeper of records on the birds he observes. Katherine Meier-Davis is a fifth-grade student who enjoys feeding wild birds. The authors have collaborated on a review of birding software for children.