Warbler Guy, which warblers are the most confusing to identify because they look like other species? Any tips to identify look-alike warblers?

 

Jamie (in Boston), I like the pictorial guide to confusing look-alike species in The Warbler Guide
("Comparison Species" corresponding to each warbler account and, in addition, pages 512-519 within the "Similar Non-Warbler Species" section).

(Orange-crowned Warbler is shown above.)

In this section, photographs of these look-alike birds feature both Ruby-crowned and Golden-crowned Kinglet, Bushtit, Verdin, Blue-gray Gnatcatcher, Black-Capped Chickadee, Blue-headed (and Plumbeous and Cassin's) Vireo, Yellow-throated Vireo, Red-eyed Vireo, Warbler Vireo, Philadelphia Vireo, Bell's Vireo, Sparrow species, and Eastern Towhee.

This field guide is excellent and recommend it for many other outstanding features that few other field guides host.

Happy Birding On These Last (Precious) Days Of Summer (!), Daniel

danieledelstein@att.net

warblerwatch.com
(hosts my resume and my "Birding Tours" information....in addition to
birding articles, etc. at the "Birding Links" tab-button)

Warbler Guy: Which “strange” common names were previously designated for some of our wood-warblers?

 

(The above Black-Throated Blue female's vastly different appearance in comparison to a definitive male of the species is suggested to be the reason John James Audubon named it a different common name, the Pine Swamp Warbler.)

Common Yellowthroat was once often referred to as Maryland Yellowthroat. John James Audubon mistakenly named two Yellow Warblers as Children’s Warbler. In another instance, Audubon misnamed two juvenile Yellow Warblers as Rathbone’s Warbler.

Audubon was not alone in his naming confusion. Beyond Audubon, naturalist/painter Alexander Wilson also made his share of identification mistakes. Both of these luminaries – as well as other contemporary birding experts in bygone eras – are to be excused because during their tenures little was known about the relationship between plumage changes and corresponding definitive field characteristics.

Audubon’s failed nomenclature decisions periodically continued to surface as he gathered specimens for his paintings. Originally calling a bird specimen he collected in Pennsylvania the Pine Swamp Warbler, he later realized his subject was truly a Black-Throated Blue Warbler.

Later, Audubon was misled by Wilson’s naming procedure into thinking a Blackburnian Warbler was worthy of being designated a new species, the Hemlock Warbler. Audubon, in fact, was never able to correct this misnaming mistake. Another misplay hearkens to May 1812, when Audubon caught a wood-warbler specimen that he named Vigor’s Warbler in honor of Nicholas Vigor, an English naturalist. More correctly, Audubon’s find was an immature Pine Warbler. His confusion was probably the result of the collected individual being in vastly different habitat than its usual pine/needle tree haunts.

Even the Canada Warbler was originally misnamed by Audubon. When he first drew the bird as it perched on the fruiting branch of a magnolia, Audubon suggested it be named the Cypress Swamp Flycatcher. Later he changed his mind, renaming the bird as Bonaparte’s Flycatcher only to again change its designation to Bonaparte’s Flycatching Warbler.

Eventually, it was confirmed that Audubon’s specimen was instead a young female Canada Warbler. Eight years later, Audubon painted the same species and mistakenly called it a Canada Flycatcher.

Regards, and happy birding....and please feel free to see my web site (WarblerWatch.com) that hosts a

"Birding Tours" section where details are present in relation to my 20+ years of bird guiding ....in addition to handouts associated with bird taxonomy, bird vocalizations, etc., et al (See "Birding Links" area at WarblerWatch.com)

Warbler Guy, how do I know if my California bird sightings are rare ones? Are species of special concern in California present in a book?

 

Sherry, feel free to see:

http://www.dfg.ca.gov/wildlife/nongame/ssc/birds.html

Here, you'll see the publication whose cover is shown below. 

It's an excellent resource to read analysis of the status of California's at-risk birds using the latest data to describe current populations, ranges, and threats. 

Species highlighted in this 450-page book include seabirds, raptors, shorebirds, waterfowl, and perching birds, all of which are represented on a Bird Species of Special Concern list.

This list also notes California habitats with high numbers of special concern bird species, including wetlands, scrublands, grasslands, and riparian forests.

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

 

Warbler Guy, Where may I most likely see warblers this time of year 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):
http://www.marintrails.com/birds.html

(By the way, my Web site, www.warblerwatch.com, features a button -- "2016 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 sometimes extract one from the landscape.

The Stinson Beach area is another "hot spot" for periodic sightings of uncommon overwintering/non-breeding season warblers, with NASHVILLE WARBLER and HERMIT WARBLER seen there on 12/5/16 by Peter Pyle. Check out sialia.com under his North Bay Birds listserv post, if you wish directions to the grove of trees where he saw these two species (as I know it's often a prime spot to watch for warblers in December/January annually).

Regards, Daniel

warblerwatch.com

(features my "Birding Tours" information for the 8-hour trips I often lead for birders)

Warbler Guy, which wood-warblers are endemic nesters to the continental U.S.?

 

Not many, Giselle, as only the Swainson’s, Virginia’s, Kentucky, Hermit, Golden-cheeked, and Yellow-throated Warbler have breeding ranges limited to areas within the lower 48 states.

To clarify, the Blackpoll Warbler does not qualify as an endemic nester to the continental U.S. because it breeds extensively in latitudes north (and into Canada) of the places where it breeds in the northern U.S.

(Below photo shows a male Kentucky Warbler.)

Warbler Guy, I heard World Migration Bird Day is happening soon? When? Where? How do I submit my data from sightings on this upcoming day?

Good question, Tony (in San Francisco): In 2021, World Bird Migration Day (WBMD) is celebrated on the second Saturday of May in Canada and the US (May 8th in 2021), and the second Saturday of October in Mexico, Central and South America, and the Caribbean (October 9th in 2021).  Tony: To learn more about WBMD and events happening near you (if any), go to: https://www.worldmigratorybirdday.org/events-map You might also be interested in other info. related to this annual event, via: https://www.worldmigratorybirdday.org/ Of course, you can submit your bird your bird migration observations on either date noted above  (i.e., spring migration day on 5/8/21 and 10/9/21 southbound/autumn migration (for the N. Hempisphere)) by going to: ebird.org/home Lastly, Tony, perhaps you'd like to create your own local WBMD event? If so, register by going to: https://www.worldmigratorybirdday.org/register-your-event Questions? Contact your local Audubon chapter....One good one for you, Tony, is to email: Ilana at idebare@goldengateaudubon.org.  She's a member of a local Audubon chapter involved in WBMD or she and her staff will know about it via: Golden Gate Audubon Society 2530 San Pablo Avenue, Suite G Berkeley, CA 94702 (510) 843-2222 http://goldengateaudubon.org

Warbler Guy, what’s an example of a “superspecies” in the wood-warbler family?

 

What’s an example of a “superspecies” in the wood-warbler family?

(The Black-throated Gray Warbler in the above photo is one of five species within the Black-Throated Green superspecies group.)

Thanks for the query, Ms. Jones (in Santa Barbara, CA).

Think of a superspecies as a group of related species that evolved from a common ancestor, but live in distinct ranges apart from each other. A good example of a superspecies is the Black-throated Green Warbler group that includes this species as well as Townsend’s, Hermit, Golden-cheeked, and Black-throated Gray Warblers.

Each of the latter four species in the above group is thought to have evolved from its Black-Throated Green ancestor. As this species expanded from its southeastern USA deciduous forest territory into coniferous forest created by the most recent glacial advances, isolation occurred among populations. 

As generations of separated populations slowly spread west and north throughout lower North America, each population became a divergent “island.” Gene flow ceased as reproductive isolation caused speciation to occur over eons. The resulting five species share various field marks, but also express their own unique characteristics.

Nonetheless, despite their status as species, hybridization sometimes occurs among species within a superspecies, including the Black-Throated Green superspecies wherein populations of Townsend’s and Hermit hybridize in Oregon and Washington. 

To simplify, where both species occur, over time Townsend’s appear to usually dominate and increase in number.

More technical, the five species within the Black-throated Green superspecies have parapatric distributions. That is to say, each of the five species has ranges that do not significantly overlap but are immediately adjacent to each other (and/or occur together in a narrow contact zone, with the aforementioned reference to Townsend’s and Hermit Warbler hybridization a scenario where overlapping occurs).

To learn more about this subject, read a classic article by R.M. Mengel titled “The probable history of species formation in some northern wood warblers.” One source where this article appears is in a 1964 edition of “Living Bird” (page 943). Note: R.M. Mengel's book is accessed via: https://www.amazon.com/PROBABLE-FORMATION-NORTHERN-WARBLERS-PARULIDAE/dp/B000WQF1WE