Friday, December 17, 2010

Warbler Guy, what are the latest bird name changes (in the 51st AOU Checklist supplement)?

Good question, Jeremy (one of my most frequent Warbler Guy inquirers).

Check out David Sibley's article about the latest American Ornithological Union-based common bird name changes at:

At this link, you'll see name changes at both the genera (scientic name) and common name level for North American songbirds. For wood-warblers, only scientific name changes have occurred, principally in the genera Vermivora and Seirus (with the latter, after the changes, now containing ONLY one member: Ovenbird).

By the way, changes in the common names of birds is available for purchase at the AOU's web site where you can obtain the 51st Annual AOU Checklist Supplement.

Sunday, December 12, 2010

Warbler Guy, how did so many kinds of wood-warblers evolve?

Joe (in Kincaid, OR), I'll answer that excellent question more fully soon, but first let me point you to an
excellent related article in a birding blog:

Friday, November 19, 2010

Warbler Guy, are there any New World warblers that occur in their own family and where shall I look?

The Olive Warbler, Peucedramus taeniatus , is a small passerine bird. It is the only member of the genus Peucedramus and the family Peucedramidae.

Breeding from southern Arizona through New Mexico and south into Mexico and Nicaragua, the Olive Warbler is the only member of the genus Peucedramus and the family Peucedramidae. All our other New World warblers are in the Parulidae family.

The Olive Warbler status in its one-member family is distinctive in that it's the only bird family endemic to North America (including Central America). Before it was classified into its current family, this warbler was considered a Parulidae, but DNA studies suggest that it split early in its evolutionary history from the other related passerines prior to the differentiation of the entire New World warbler/American sparrow/Icterid group.

Thus, bird taxonimists now place the Olive Warbler in a family of its own.

Like many other New World warblers, it is an insectivorous species of coniferous forests.

Though it is often said to be non-migratory, most New Mexican birds leave the state from November to late February. It lays 3–4 eggs in a tree nest.

Wednesday, November 10, 2010


Can you identify the wood-warblers in each of the following five photos?

Wednesday, November 3, 2010

Warbler Guy, can you tell me some of the most abundant wood-warblers that were seen in last year’s Christmas Bird Count?

Yes, Brent in Orange Co., CA, there’s a record of these results in the latest American Birds (110th CBC, Volume 64).

Consider the following highest totals and the corresponding location/name of the CBC:

- Olive Warbler, 9 (AZ, Green Valley-Madera Canyon)
- Tennessee Warbler, 2 (TX, Guadalupe River Delta-McFaddin Family Ranches)
- Oranged-crowned Warbler, 493 (TX, Weslaco)
- Nashville Warbler, 10 (TX, Weslaco)
- N. Parula, 18 (FL, Kendall Area)
- Yellow Warbler, 11 (CA, San Diego; FL, Coot Bay-Everglades N.P.)
- Chestnut-sided Warbler, 1 (AZ, Phoenix-Tres Rios)
- Magnolia Warbler, 3 (FL, Coot Bay-Everglades N.P.)
- Cape May Warbler, 1 (OH, Ragersville)
- Black-throated Blue Warbler, 2 (FL, Coot Bay-Everglades N.P.; Ft. Lauderdale; Kendall Area; and Key Largo-Plantation Key)
- Yellow-rumped (Audubon’s), 4,638 (CA, Orange Co.)
- Yellow-rumped (Myrtle), 7,599 (SC, Charleston)

Sunday, October 17, 2010

Warbler Guy, did Kirtland’s Warbler nest in Wisconsin again this past breeding season?

Wisconsin Kirtland's Warbler Nesting Update

Yes, Avery (in Chicago), the federally endangered Kirtland’s Warbler observations totaled a minimum of 24 male and 13 female individuals in the state. Among 16 nest sites monitored, three to five were successful, appearing to fledge an estimated 12 to 18 newborns.

Monitoring of nests or sightings of Kirtland’s Warbler (above photo) occurred in several Wisconsin counties — Adams, Marinette, Bayfield, Douglas, and Washburn. In Adams County, 20 male and 11 female Kirtland’s were documented. In turn, estimates of fledglings from these totals in 2010 ranged from 12 to 18 among three to five nests.

In Marinette County, a volunteer monitor found a single Kirtland’s at the same site where he documented nesting in 2009. Another single Kirtland’s male was also reported at another site in the county where birds were found in 2008 and 2009, and three males were documented at a third site.

In Bayfield County, a single Kirtland’s male was discovered on Bayfield County Forest land in early June and a follow-up visit yielded a second male plus a female.

In Douglas County, a single Kirtland’s was seen on the same date as the aforementioned Kirtland’s observed in Bayfield County. However, a follow-up visit by researchers failed to detect any presence of Kirtland’s so nesting could not be confirmed for 2010 here.

In Washburn County, a male Kirtland’s was observed, but a nest could not be found.

Interestingly, all 10 banded male Kirtland’s present in Adams County in 2009 returned in 2010, including one individual that had been originally banded in the Bahamas.

This year’s breeding results confirm that Kirtland’s Warbler has nested for four consecutive breeding seasons in Wisconsin. This sequence in unprecedented in the monitoring of this species that previous to 2007 was thought to primarily to exclusively nest only in 10 or so north-central Michigan counties. Given the now-annual breeding of Kirtland’s in Wisconsin, it’s safe to suggest the species now regularly nests in both states.

Monday, September 27, 2010

Warbler Guy, do the white tail spots in the Hooded Warbler (and other warbler species) provide it any benefit?

Catrina (in Portland, OR), the answer is “yes,” if you agree with studies conducted by Dr. Ron Mumme. In the field, he tested his hypothesis that the Hooded Warbler’s (above photo courtesy of Dr. Mumme) contrasting white tail spots and tail-flicking behavior increase foraging performance by startling potential insect prey that the warblers then pursue and capture in flight.

Results of his experiment indicated that Hooded Warbler individuals with darkened tails had significantly lower prey attack rates and delivered significantly less food to nestlings than did birds with normal, unchanged tail feathers. He and other theorists continue to test their theory about the importance of contrasting tail pattern in helping birds capture prey, and, in doing so, note that all 12 species in the Myioborus redstarts (also known as whitestarts) display similar behavior while using their white outer tail feathers to also conduct foraging displays designed to startle and flush potential insect prey.

Wednesday, September 15, 2010

Warbler Guy, which warblers are superspecies?

That’s a fine question, Jeremy (in Boise, ID).

Given a superspecies consists of two or more species that evolved recently into isolated breeding ranges next to each other, it is not surprising that superspecies’ members are closely related.

Among songbirds, think of Eastern and Western Meadowlarks. Their breeding ranges are separated across North America and are nearly isolated except for a small overlap area. The same kind of breeding isolation geography pattern occurs in more than 100 North American species that are considered members of 53 total superspecies.

Of these 53, some wood-warbler species qualify. Note the distinct breeding ranges of the Black-throated Green superspecies consisting of this species along with Black-throated Gray, Hermit, Townsend’s, and Golden-cheeked Warbler.

Other warbler superspecies include 1) Nashville, Virginia’s, and Colima; 2) Northern and Tropical Parula; 3) Yellow-throated and Grace’s; and 4) Mourning and MacGillivray’s.

Tuesday, September 7, 2010

Given, I saw your 9/2/10 article here, what warbler identification resources exist?

Eddy in Chicago.......That's a good question.

Violating my own anti-shill policy, I'll suggest my own "Warbler Tips ID" chart (that is accessed at my web site's home page:

This chart has a column that lists the look-alike species, in addition to mentioning 1) whether they are early to late spring arrivals/autumn departures during migration; 2) their conservation status; 3) other information.

The direct link to this warbler identification resource:

Thursday, September 2, 2010

Confusing Fall Warblers? Warbler Identification Tips?

People often ask me to share the best ways to identify migrating warblers — especially in the East and Midwest where post-breeding plumages can sometimes create identification challenges.

My brief answer is that there’s no replacement for doing your homework in the field. Getting out early and often with your binoculars is the best way to see lots of warblers. The more challenging identification episodes you encounter, the faster you become precise with your warbler field skills.

One identification resource I recently found may interest you. It’s an online “chart” that’s found at:

The author, Marcel Gahbauer, does a terrific job of separating 30 species of warblers by various key feather field marks: a) presence of wingbars or not; and b) facial, throat, and undertail characteristics.

Enjoy your late summer and autumn birding!

Wednesday, August 18, 2010

Warbler Guy, which wood-warblers use cavities for nests?

Only two of our North American breeding wood-warblers use a cavity nest: Prothonotary (above photo) and Lucy’s.

Prothonotary nests usually occur in stumps and snags either standing in or near water. An old or abandoned woodpecker hole is typically employed, most often one previously occupied by a Downy Woodpecker or Black-capped/Carolina Chickadee. Nest heights range from 2 to 12 feet above ground or water, with an average of 5 feet in height. Prothonotaries occasionally nest in bird boxes and near buildings.

Lucy’s Warbler is the only cavity nesting warbler in the western USA. This species usually places its nest in four types of cavities: natural cavities in trees (usually mesquite) where the entrance is in a sheltered spot; under loose bark; in abandoned woodpecker holes (especially those of Gila Woodpecker (Melanerpes uropygialis) in saguaros [Carnegiea gigantean] or other trees); and in deserted Verdin (Auriparus flaviceps) nests. Lucy's Warbler occasionally nests in holes in banks, in soap tree yucca leaves (Yucca elata), elderberry (Sambucus mexicana), sycamore (Platanus spp.), or willow/

Lucy's Warbler rarely nests in burrows or depressions in river banks, rocky crevices, deserted thrasher (Toxostoma sp.) and Cliff Swallow (Hirundo pyrrhonota) nests, "pseudocavity" evacuated in mass of debris in tamarisk, or forks in small branches.

Wednesday, August 4, 2010

Warbler Guy, were any changes in warbler names recently applied?

Yes, David (in Topeka, KS), the 51st supplement to the AOU Checklist of North American Birds includes changes to warblers names, but mostly due to the creation of new genera.

The new supplement includes the following changes:

• Blue-winged Warbler Vermivora cyanoptera
Formerly Vermivora pinus
• Tennessee Warbler Oreothlypis peregrina
Formerly Vermivora peregrina
• Orange-crowned Warbler Oreothlypis celata
Formerly Vermivora celata
• Nashville Warbler Oreothlypis ruficapilla
Formerly Vermivora ruficapilla
• Virginia’s Warbler Oreothlypis virginiae
Formerly Vermivora virginiae
• Colima Warbler Oreothlypis crissalis
Formerly Vermivora crissalis
• Lucy’s Warbler Oreothlypis luciae
Formerly Vermivora luciae
• Northern Waterthrush Parkesia noveboracensis
Formerly Seiurus noveboracensis
• Louisiana Waterthrush Parkesia motacilla
Formerly Seiurus motacilla

Saturday, July 24, 2010

Warbler Guy, which wood-warbler clutch has the largest number of eggs?

Good question, Parker in New York City.

The answer is the Cape May Warbler (see female in photo, above), which usually lays six or seven eggs. Most other wood-warbler species typically lay four or five eggs in most instances. In extraordinary cases (that are seldom to rare), the Cape May deposits as many as nine eggs. In equally rare situations, merely four are laid.

Why does the Cape May lay eggs than other wood-warbler species? The answer may relate to the “boom and bust” cycle of its dominant food resource: spruce budworms (a larval form of a moth). When large population outbreaks of the spruce budworm occur, it behooves the Cape May to lay more eggs. Conversely, it makes sense that this species lays fewer eggs in years when spruce budworms are less plentiful.

Of course, this kind of phenomenon is not unique to Cape May Warbler. Many other bird species, in addition to other animals, act similarly in response to the presence or absence of food resources.

For more details about clutch sizes of North American breeding wood-warbler, see The Birder’s Handbook (Paul R. Ehrlich, David S. Dobkin, and Darryl Wheye)

Other life cycle information about USA-breeding wood-warbler species appears in a “Warbler Tips ID Chart” at my Web site: (After arriving at this site’s home page, click on the button title “Warbler Tips ID Chart.”

Saturday, June 12, 2010

Warbler Guy, which vagrant warblers have recently been seen in Alaska?

Good question, Thomas (in Cincinnati, OH).

According to the May, 2010 issue of Birding Magazine, the Willow Warbler (ABOVE PHOTO) (Gambell, St. Lawrence Island, 8/25/02), Sedge Warbler (9/3/07) and Pallas’s Leaf Warbler (9/25/06) are the three most recent significant observations.

(By the way, a vagrant bird is one that appears far outside its normal range. Some people believe “accidental” equates with vagrancy. Among a number of factors that cause a bird to become vagrant, genetics and weather conditions are two.)

Which warblers are predicted as upcoming potential vagrants to Alaska?

Candidates include Gray’s Warbler, Oriental Reed-Warbler, Black-browed Warbler, Pale-legged Leaf Warbler, Radde’s Warbler, and Japanese Bush-Warbler.

Wednesday, May 19, 2010

Warbler Guy, what are some good warbler identification resources?

Andy (in Lacrosse, WI), I suggest you see:

Tuesday, May 11, 2010

Warbler Guy, do migrating male wood-warblers arrive earlier than females to nesting grounds?

(Above, a first-year male American Redstart is indicated by the slightly burnt-orange/amber outer tail feathers and forward flanks.)

Yes, Edward (in Cincinnati), multiple studies indicate males arrive earlier than females. One study (at Prince Edward Point, Ontario) even showed that the oldest adult American Redstarts arrived significantly earlier than second-year males of the same species. A similar trend was noted for approximately 20 other wood-warbler species.

Interestingly, species that spend the winter farthest north, arrive the earliest upon nesting grounds. That makes sense in the case of Yellow-Throated Warbler that arrive early in the spring in the Mid-Atlantic because they merely need to travel from as closeby as the southeastern USA where they spend the non-breeding season. This phenomenon supports the theory that males arrive early to take advantage of food resources and/or when climatic conditions are suitable, whereas females of the same species arrive when conditions are more ideal for successful nesting.

Later arriving species on their nesting grounds, including Blackpoll, travel from as far away as northern South America where they spend the non-breeding season. For this reason, during some spring seasons, it may not arrive on northern nesting grounds until June 1st and beyond.

Other wood-warbler species — Yellow-rumped and Pine Warbler, for example — that can subsist on berries and seeds, in addition to insects, are usually the earliest to arrive on nesting grounds. Among other early arriving species in the warbler march north include Palm, Black-and-white, Nashville, Wilson’s, Louisiana Waterthrush, Prothonotary, Northern Waterthrush, Wilson’s, and Yellow.

Tuesday, April 27, 2010

Warbler Guy, do all our returning eastern wood-warblers fly over the Gulf of Mexico during spring migration?

(Nashville Warbler, above. Note it’s often difficult to see its light brown-orange cap, though its prominent eye-ring and absence of wingbars are good field marks.)

“No,”(Byron in Laramie, WY) is the quick answer.

Although the majority of East Coast and Midwest breeding wood-warblers fly over the Gulf upon returning to the USA, there’s at least three that fly around the Gulf:
Nashville, Mourning, and Canada.

That is to say, these three “Circum-Gulf” migrating species use an overland route by arriving in the USA via Mexico.

The non-breeding season range of the Nashville Warbler is primarily in Mexico, so they have the least amount of miles to travel as migrators. Moving north in spring, they typically always arrive earlier than Mourning and Canada in northern Midwest and Eastern latitudes. In fact, among the 30 or so wood-warblers that birders observe annually in northern latitudes, Nashville may be considered an early arrival among the vanguard. Some of the Mexican wintering Nashville travel to the West Coast for breeding and are considered a different subspecies.

Canada and Mourning, on the other hand, are known as later arrivals in the warbler migration parade. Canada comes all the way from southern Central American and northern South America, so it makes sense that its route through Mexico takes longer than many other warbler species.

Patient birders often have to wait even longer into May to see Mourning. That’s because it winters almost exclusively in northern South America. Winging north requires Mourning to travel more miles than most arriving Nashville and Canada populations. As a result, Mourning usually doesn’t appear in its breeding territory until mid-May, often later in some spring seasons.

If, for example, cold weather occurs throughout much of May and northerly breezes prevail, then Mourning may not arrive until late May in portions of its northern nesting areas. Only Blackpoll is known to arrive later during these inclement seasons when many other warbler species may also arrive later than usual.

Wednesday, April 14, 2010

Warbler Guy, what are the answers to the most recent quizzes on your blog’s right column? (Jeremy K., Seattle, WA)

Here’s the answers, Jeremy, with corresponding date (if applicable) for each quiz provided as you scroll down from today’s date and backward in time:

1. March 2 Photo Quiz:

Photos from top to bottom = MacGillivray's, Connecticutt, Chestnut-Sided, Lucy's, Hermit

2. Which wood-warbler is typically the earliest long-traveling migrant back on the East Coast? West Coast?

Answer: Louisiana (remember, it said “long-traveling” migrant); Orange-crowned

3. March 1, 2010 article and corresponding quiz:

Which wood-warbler species has gained the most population by percentage in the last 20 years?

Answer: Kirtland’s, as the population increased to nearly 1,400 singing males by the mid-2000s after hovering around 200 males through the mid-80s.

4. January 10 Photo Quiz:

Photos from top to bottom = Aud.'s) Yellow-Rumped, Wilson's, Bl.-Thr. Blue, Blackpoll, Hermit

5. Approximately how many miles are trans-oceanic migrating Blackpoll (Warbler) traveling if they begin in New England and arrive in northern S. America (For help, see the 9/29/09 article)?

Answer: 2,150 one-way (for example, Blackpolls leaving New England travel as far as this distance to northern South America where they spend the non-breeding season.

6. Pretend you're attending an upcoming Christmas Bird Count (CBC) in any of the lower 48 states. Which two wood-warbler species are the most likely ones MOST people would see?

Answer: In most cases and during most years, it’s Yellow-Rumped and Common Yellowthroat (though Palm can sometimes persist and/or over-winter in some northern latitudes).

7. Can you name two wood-warbler species that are breeding endemics to one USA state?

Answer: Golden-cheeked (a true endemic that breeds only in Texas) and Tropical Parula, though the later breeds farther south outside Texas.

Sunday, March 28, 2010

Warbler Guy, which warblers look alike? Which are the most confusing warblers to identify from each other?

Thanks, Gilman (in Paso Verde, CA)

Right, which photo is the Orange-crowned? Tennessee?

Warbler identification challenges are ALWAYS the leading questions I get in the spring.

So here's ten typical “double-take” ID challenges you’re likely to encounter when the going gets tough on the boardwalk as the warbler march begins:

(i.e., Knowing the breeding ranges and which habitats the following species tend to frequent and/or nest within is always helpful in identifying look-alikes from each other – among other factors.)

1. Chestnut Sided and Golden-Winged

2. Magnolia and immature Prairie

3. Black-throated Green and Townsend’s/Hermit hybrids

4. Yellow-throated and Grace’s

5. Kirtland’s and Palm (and Prairie)

6. Yellow-Rumped (Audubon’s subspecies vs. Myrtle subspecies) (and intergrades of Audubon’s and Myrtle occur in portions of British Columbia and Alberta)

7. Tennessee and Orange-Crowned

8. Ovenbird and Northern Waterthrush (or Louisiana Waterthrush (they are all in the same genus)

9. Connecticutt and Mourning

10. Mourning and MacGillivray’s

Saturday, March 20, 2010

Warbler Watch (Indeed): Daniel's Upcoming Birding Forays

If you're in the Bay Area/California, then maybe you'll appreciate noting my upcoming birding outings:


Upcoming Birding Field Trips
with Daniel Edelstein (

(Birding Instructor @ Merritt College, Birding Guide
& Wildlife Biologist;

Low Cost: $25 per full day field trip
($20 per day if you register for four or more field trips)

Visit the best birding sites in the Bay Area & Sierras (@ peak of breeding/song)

Daniel’s 25+ years of ornithology/biology experience,
plus handouts you’ll receive (and use of his A-1, 25x-50x zoom scope & binoculars)

1. Bay Area (i.e., to prime-time songbird (“Birding By Ear”) hot-spots)
- April 17th, Mitchell Canyon, Mt. Diablo State Park, Walnut Creek,
9 am – 3 pm
- April 31st, Mines Road/Del Puerto Canyon, Livermore area,
9 am – 3 pm
- May 8th, Point Reyes National Seashore, Bear Valley
9 am – 3 pm

2. Sierras (i.e., we’ll visit optimum breeding areas for common & rare birds)
- June 5-6, Yuba Pass/Gold Lakes area (Sardine Lake, Sand Pond, etc.)
- June 12-13 Sierra Valley (Marble Hot Springs Rd., Dyson Lane, Loyalton area)

Cost: $25 per day’s outing or any five days for $100 (Minimum of eight people needed to ensure each day’s field trip is a “go.”)

Directions/Etc.: If you respond with a “yes” to one or more of the above dates, I’ll send you precise directions/maps/motel-camping options, details/etc.

Email questions to Daniel (an Adjunct Merritt College instructor in its Biology Dept.):

Learn about Daniel’s 25+ years of birding experience and print FREE Bay Area/ California birding information at: &, in addition, please note Daniel’s popular “Wood-Warbler” blog site:

Tuesday, March 2, 2010


Can you identify the wood-warblers in each of the following five photos?

Saturday, February 13, 2010

Warbler Guy: Do any wood-warblers use cavities for nesting?

Lynnette in Elm Grove, WI asks an interesting question.

Jeanne Marie Acceturo is our guest writer who has ALL the answers for you:

One hundred fourteen wood-warbler species nest in the Americas and Bahama Islands. But only two of them use cavities for nesting: the Prothonotary Warbler (Protonotaria citrea) (PRWA, bottom photo) and Lucy's Warbler (Vermivora luciae) (LUWA, top photo).

Newly returning males of both species will soon arrive after migrating. They’ll define and defend territories before females arrive a week or two later (in April for the bulk of most breeding sites in the United States).

Males do all the wooing. Females make all the choices. Her big decisions: Which male has excellent taste in real estate? What constitutes a million dollar listing in the wood-warbler world?

Unlike PRWA and LUWA, other wood-warbler species prefer nesting sites within dense shrubs, atop a tree branch, or in a nook under a tangle of ground cover. Our two cavity nesting wood-warblers prefer otherwise, instead often utilizing dead snags or live trees where standing water provides a moat directly below the nest site.

Last year’s Downy Woodpecker hole? To a PRWA, it’s the perfect choice. Bald cypress, willow and sweet gum are the typical host trees. Male PRWAs make a platform of moss inside each suitable cavity in their territory. The females construct the nest and include mosses and liverworts.

Why? Perhaps it’s because damp nesting material increases humidity inside the cavity so that eggs are less likely to dry out.

But that still doesn’t explain why PRWAs use cavities. The mystery remains. One theory relates to the added protection obtained from living inside a limb hidden from predators such as marauding rat snakes.

In an all-too-familiar story, however, much of their preferred bottomland hardwood forest is disappearing. People have destroyed 90 percent of this habitat for logging, agriculture and other development. Fortunately, there’s good news: PRWAs sometimes use nest boxes when they’re erected in suitable locations.

Lucy's Warbler, the West Coast first cousin of the more East Coast based PRWA, also nests near water. But where’s a LUWA likely to find water within the lower Sonoran desert habitat that it favors? Not too many places. So LUWA changes its game plan: old Gila Woodpecker holes or abandoned Verdin nests sometimes become Home Sweet Home. So do crevices behind loose tree bark, natural cavities, or, less commonly, spaces among large networks of loosely tangled roots in riverbanks.

Populations of LUWAs have dropped for an obvious reason: the Southwest has been developed intensely. Unfortunately, LUWA rejects nest boxes, but where LUWA’s natural habitat of mesquite forest has been lost to logging and water diversion, introduced (and invasive) tamarisk trees pinch hit as substitute nesting sites.

Are either PRWA or LUWA listed as threatened or endangered? Not yet, but conservation of these two species’ remaining populations presents a cautionarytale — one that depends on habitat conservation as a rule and not an option.

Lucy's Warbler Photo: © Dominic Sherony; Prothonotary Warbler Photo: © Mdf

Sunday, February 7, 2010

Warbler Guy, Help Me?: I’m in Florida and wondering if the photos here are western or eastern subspecies of Palm Warbler?

Thanks for the question, Mr. King. (Both photos courtesy of an excellent birder, Jim McGinity.)

Your photos are both “Western” Palm Warbler, despite your East Coast location.

That’s because during the “winter,” it’s possible to see both the subspecies that occur within the Palm Warbler species.

More details follow:

Telling both subspecies apart in the winter/non-breeding season may and can be challenging. Underline the last sentence (!)

To wit: Although you can see both subspecies during the non-breeding season/winter in Florida, the pale “Western” subspecies (Dendroica palmarum palmarum) often adds a touch more of yellow under its belly during the fall (through winter).
For this reason, some population members of “Western” may look like the “Yellow” (East Coast” subspecies, D. p. chrysolepis. The latter (the “Yellow” East Coast version) is much brighter during the breeding season than the “Western” Palm Warbler subspecies.

Got all that?

If not, here's a MAJOR tip.....

It’s an excellent field mark that helps you tell the two subspecies apart:
the yellow eye-ring that’s shown in the “Yellow” Palm Warbler (D. p. chrysolepis).
In contrast, the “Western” Palm has a WHITE eye-ring.

Even more details about the two subspecies yellow color follows:
“Western” yellow has a contrasting pattern where the yellow ends and the rump is a duller green (but more yellow in the “Yellow” East Coast subspecies (D. p. chrysolepis).

Note there are intergrades and, indeed, a potential breeding area in Canada where both subspecies may successfully mate with each other and have viable offspring.

Despite all the details I’ve already present, this account oversimplifies how to identify both subspecies from one another. Excellent drawings of both subspecies appear in “A Field Guide to the Warblers of North America” (Jon Dunn and Kimball Garrett) (plate #20, page 82). More details about how to tell them apart are described on p. 366 in this book.

The plates are “Must See” viewing for warbler fans like you, Mr. King, but I hope the account above answers your question.

If not, please ask me more questions.

That’s why I’m here as “The Warbler Guy.”

Monday, February 1, 2010

Population Explosion?: Kirtland's Warbler Responds To Wildlife/Habitat Management

See the current quiz on the right side?

Now look at the above graphic that shows the annual population changes of Kirtland's Warbler in Michigan during the last 20 years.

Hmmmm.......Do you think the current majority of folks who answered the quiz are correct? Incorrect?

Truth be told, the Michigan DNR's habitat management plan is a huge victory for the federally endangered Kirtland's.
Their populations in 12 central-northcentral Michigan counties continue to thrive. Prescribed fires have helped create optimum conditions in their Jack Pine community whereby managers have helped Kirtland's rebound from the brink of extinction in the late 1980s.

For more information, see:,1607,7-153-10370_12145_12202-32591--,00.html#quickfacts

Of course, Wisconsin breeding populations of Kirtland's are also big news. During the past three breeding seasons, Wisconsin has hosted newborns in at least two counties. For more details about the discovery of Kirtland's Warbler in Wisconsin and an overview of their breeding abundance, see one or more of my June and July, 2009 updates/articles in the archives section of this wood-warbler blog.

Sunday, January 17, 2010

Warbler Guy, Where may I most likely see warblers in northern California near you (or where might I see warblers in Marin County)?

Thanks for asking, Jeremy (in Mill Valley, CA).

Here's a great web site to note seven fine Marin County birdwatching spots (i.e., the best birding places in Marin County, and, arguably, some of the finest birding locales in northern California):

(By the way, my Web site,, features a button -- "2010 Nature Watch Calendar" -- where you can read several brief accounts that discuss wood-warblers in northern California and, in particular, wood-warblers in Marin County.)

Currently, among the seven on the list, I suggest going to Rock Springs (on Mt. Tamalpais) and
Muddy Hollow (within Point Reyes National Seashore, a paramount, iconic place on the W. Coast to see diverse species of birds in multiple families/orders).

In these two spots where forests occur, the most likely wood-warblers to see currently include TOWNSEND'S WARBLER (non-breeding season resident only; see closest above photo) and YELLOW-RUMPED WARBLER (typically the AUDUBON's subspecies).

At Rock Springs and Muddy Hollow, watch for the much less common (in this order) ORANGE-CROWNED and HERMIT WARBLER, too -- though they are both rare to absent throughout most of Marin Co. during January (Populations of these two neotropical migrants return in late winter and spring, thereby nesting in suitable habitats throughout the County.) Even more rare at this time of year is to see the NASHVILLE WARBLER (above photo, below the headline), though it periodically makes a cameo appearance and, indeed, the local annual Christmas Bird Count surveyors such as Rich Stallcup sometimes extract one from the landscape.

Sunday, January 10, 2010

#2: Fab Five Warbler Quiz

Can you ID the five wood-warblers in the photos? (Answers will be here by 1/20/10; please check back)

Please see the nearby quiz where you can select your answers.

{As promised, here's the answers to the 12/27/09 quiz, below (from top to bottom):