Sunday, December 17, 2017

Warbler Guy, where can I read about multiple warblers' nesting habits, warbler migration patterns, warbler songs, etc.?

Syd (in New York), you cannot go wrong by visiting:

This site features a comprehensive list of more than 720 North American species, with all of this area's Parulidae (warbler family) members present.

Yes, it costs money: $42 per year or $100 for three years.

Cannot recommend it enough. Thumbs (way) up (!)

Happy Holidays, Daniel

warblerwatch (features my "Birding Tours" area and birding information for n. CA)

Friday, December 8, 2017

Warbler Guy, is it common to see warblers during the winter? Are sightings of non-breeding season warblers typical in the East and Midwest?

Greg (in Baltimore), I could provide you details, yet definitely not better than the following fine article at Nemesis Bird that provides an explanation of "winter" warbler abundance for the East:

As for the West, say, in northern California where I live, the most typical warbler species to see (from most common to rarest in the order shown below) include:

- Yellow-rumped (both Myrtle and Audubon's subspecies occur in diverse habitats in great abundance, though Audubon's far outnumber the former);
- Common Yellowthroat (considered a resident throughout parts of n. CA, including the SF Bay Area) (male, immediately below and female below the male);

- Orange-crowned (although most depart annually be each autumn, a small number remain throughout the non-breeding season before they are again joined by returning migrants in February/March);
- Hermit (similar in abundance to the explanation noted for Orange-crowned, above);
- Palm (rare to absent during the non-breeding season, though often seen during the fall migration window....considered a vagrant sighting by many birders who observe this species in n. CA);
- Wilson's (even less common to detect during the non-breeding season than Orange-crowned and Hermit);
- Nashville (a few occur during the non-breeding season, but it's typically rare to absent)
- Black-throated Grey (rare to absent during the non-breeding season); and
- Yellow (although this species is common to see as a fall migrant throughout much of n. CA, it is usually rare to absent by November - March in this region).

Monday, November 27, 2017

Warbler Guy, which West Coast warbler vagrants are the most common ones to see? Do vagrant warblers also appear on the East Coast?

Good question, Hogie (in Portland).


On the West Coast, say, on the Outer Point of Point Reyes in N. CA, the most typical East Coast vagrants to see in the fall include Palm, Blackburnian and Blackpoll. Other species that often appear annually: Black-throated Blue, Black-and-white, Magnolia, and Chestnut-sided Warbler.

(Blackpoll Warbler, shown above.)

One reason relates to the orientation error displayed by migrating warblers. For many vagrants seen on the West Coast, the cause is due to first-year individual having an innate faulty brain, causing them to navigate south, then west — instead of south and, then, east toward Latin American expanses.
In traveling west by mistake, these newborn warblers continue as far as the land will take them — such as to the far western extreme of Point Reyes National Seashore. Unfortunately, these vagrants meet an unfortunate fate as they eventually continue moving west over the ocean.

In regard to West Coast vagrant warbler species, ongoing discussion is whether Blackpoll is truly a vagrant? -- given it's annually seen on the West Coast after the breeding season. It's possible these observed individuals nested in Alaska and, hence, migrated directly south after breeding.

In turn, the question then is whether these few sightings of Blackpoll should be termed vagrants, given many birders believe the term denotes disoriented individuals who have an in-born abnormality in their navigational abilities.

Consequently, the term vagrant remains an open question for birders wishing to debate the answer.

Perhaps the best solution is to simply use a different status identification as to whether a warbler sighting for one area deemed, for example, uncommon, unexpected and/or rare — and, thus, avoid the using the term "vagrant."

Meanwhile, consider rare sightings of warbler species on the East Coast and in the Midwest.

In these regions, it's not as common during the non-breeding season to have West Coast warbler species show up, but it does occur.

For example, in my home state of Wisconsin, it's a "big deal" for birders to see a Townsend's Warbler — which is one of the most common non-breeding season warbler species in the SF Bay Area (where I primarily live now).

A good site to check for vagrant warbler sightings throughout the USA:

A 2006 sighting of Townsend's at Sheridan Park in the Milwaukee area coaxed oodles of birders to view this vagrant. Go to the following ebird link:

to see evidence of this Townsend's surprise visit to Wisconsin.

Thursday, November 9, 2017

Warbler Guy, what's a good web site to tell warblers from one another? Here's some warbler photos that perplex me for the ID of warblers.

Jessie, try looking at:

As for your warbler photos, below, here's my opinion as to their identities (from top to bottom):

Orange-crowned, Nashville, Orange-crowned, Yellow-breasted Chat

As for apps: iBird Pro (wonderful!)....Sibley Birds (equally excellent, and especially for gull species because the age class for each "cycle" is visually expressed well).

The Warbler Guide app is OK and is complementary to the field guide with the same name....but its breadth and depth is not as advanced as iBird Pro and Sibley Birds. There are several other FINE bird apps, so I don't wish to suggest this communique is comprehensive.

Enjoy the wood-warblers and birding fun, hosts my "Birding Tours" information.....and feature my current "Raptors of San Francisco Bay" college class that continues through 11/12/17.

Saturday, November 4, 2017

Warbler Guy, I wonder what the "alula" feathers are on a bird? Do warblers have alula feathers? What function do alula feathers do?

Sherry (in Helena, MT):

Great question (but NOT always one I receive....).

Here's a photo (BELOw) of a bird — a Common Pigeon — that highlights its alula feathers and notes their function: (Wood-warbler family members ALSO possess alula feathers, but they are more challenging to see....and best seen via museum specimens and/or in the hand when banding birds at a mist net station.)

Three to five feathers in wrist of the wing that are used in slow flight or landing, much as slots on an airplane.

As for the source of this photo, I thank Vireo and R. Curtis....and feel free to see more bird terms and vocabulary at:

Enjoy the birds and don't forget to lean over and fall back tonight one hour: Daylight savings ends, I'm sorry to say....Imminently, there's one fewer hour of birding to do in the afternoon (!) 

Daniel, with 
(hosts my "Birding Tours" information for the northern and central CA area....including the SF Bay Area birding tours I regularly lead....including today, when I'll bring my "Raptors of the San Francisco Bay Area" Merritt College class to Hawk Hill in Sausalito (Golden Gate Raptor Observatory) ).

Rock Pigeon      Columba livia

Thursday, October 26, 2017

Warbler Guy, is it possible to ID the "Audubon's" Yellow-rumped Warbler vs. the "Myrtle" subspecies by call notes? Where do I learn more about telling call notes by bird species?

Good question, Kristen:

Here's one general answer, that I dare say is also an oversimplification of this complex topic.

First, you are probably aware from your smart question that a "call" note is a different and distinct vocalization than a "song," — the latter of which is typically a learned and memorize rendition sung in most cases by males as a rhythmic vocalization of one or more phrases (e.g., think of a loquacious Northern Mockingbird).

A "call" note is one element. 

Most songbirds express one call note, ala your question, above.


Obviously, Yellow-rumped Warbler individuals are NOT currently 
singing during the non-breeding season, but you do often hear 
their loud chip or call notes where the subspecies Audubon’s 
and Myrtle Yellow-Rumped Warbler forage during the non-breeding season.

This is the case throughout the San Francisco Bay area 
where I live. In the fall and through March (and, even, 
into April), most of the Yellow-rumped Warblers seen 
and heard occur as the Audubon's subspecies. 
Sometimes, I am able to spot a Myrtle 
subspecies individual....though for every, 
say, 100 Audubon's I see in the SF Bay 
Area, approximately one is a Myrtle subspecies.

(Note the Audubon's subspecies nests in 
a few higher elevations in the SF Bay Area, 
including Marin County where I live (20 miles 
north of the Golden Gate Bridge).)

In many cases you can hear how the Myrtle 
(one of the subspecies of the Yellow-rumped 
Warbler species) has a flatter and softer 
chip note than the Audubon’s.
The “ch” component of the call note is 
weaker for the Myrtle and it often gives 
many calls in rapid succession.

However, be careful. Intergrades (individuals 
that display visual characteristics specific 
to both Audubon’s and Myrtle) may 
announce call notes of the other subspecies. 
In other words, it’s possible to see a bird that 
looks like an Audubon’s, but it’s call note 
sounds like a Myrtle. This individual could 
likely be an intergrade.

Regards, Daniel
(hosts my resume and my "Birding Tours" 
information for N. and Central CA tours that 
I have conducted since 2001)

Monday, October 16, 2017

Warbler Guy, I'm planning an upcoming California birding tour and want to go with a San Francisco birding guide. As I prepare, where do I check for "rare" bird alerts that will reveal which rare California bird species are recent sightings?

Hi Davey:

Here's the answer to your question, above:

To see recent bird species sightings throughout California, feel free to check:

This link features a composite list of all California listserv sites.

Click on one or more as you please to see the latest bird sightings lists posted by


Glad to help:

One "strange but true" facet of California birding relates to how most of the state soon expresses a touch of spring (already!), given the courtship dance of male Anna's hummingbird individuals are often observed this time of year (and especially by November and December, annually).

Initial egg laying by this common, year-round resident hummingbird species occurs as early as December. Multiple broods may be tended by a female during one breeding season, with July and August the latest months each year when final active nests are observed.

As for wood-warblers typically occurring on listservs currently in the SF Bay Area where I often serve as birding guide to hot spots such as Point Reyes National Seashore (Marin Co.) and Bodega Bay (Sonoma Co.), the once abundant in-migration Yellow Warbler (late summer through September) is now a rare sighting, with only the rare individual detected on local San Francisco Bay Area Christmas Bird Count forays.

More typical, it's common to see Yellow-rumped Warbler individuals in many habitats this time of year through March (Audubon's Yellow-rumped Warbler subspecies — Setophaga cornonata auduboni) is the most abundant subspecies in this species to observe, though the West Coast also attracts the occasional to uncommon Myrtle Yellow-rumped Warbler subspecies (Setophaga coronata coronata).

Feel free to review my web site's "Warbler ID Charts," if you wish additional info. and/or see the "Birding Links" articles and my "2017 Nature Watch Calendar" where several wood-warbler articles appear, among other information elements.

Regards, Daniel Edelstein
Consulting Avian Biologist,
Birding Guide,
& Birding Instructor (Merritt College, Oakland, CA)

Tuesday, September 26, 2017

Warbler Guy, are Myrtle and Audubon Yellow-rumped Warbler their own species? Or subspecies?

Fine question, Jerry (in Chicago).

As brief background, in 2017 the American Ornithological Society (AOS) voted down a measure that would have split Yellow-Rumped Warbler into different species* (see two notes, below, for more details related to the aforementioned sentence).

Many of you already know the Yellow-rumped Warbler currently occurs as at least two, three, or four subspecies (varying among taxonomic organization plans). Among the current taxonomic plans, the “Myrtle” group (coronata), and the “Audubon’s” group (auduboni) are accepted in every one, with “Black-fronted” (nigrifrons), and “Goldman’s” (goldmani) also noted in at least one other taxonomic plan. 

NOTE  #1: In the N.A. Birds Online account for this species, the following additional subspecies is described in the "Myrtle group (below photo)":  D. c. hooveri McGregor, 1899: Breeds in central and s.-central Alaska, se. Alaska, Yukon Territory, Mackenzie, and nw. British Columbia; intergrades with auduboni known from Stikine River, AK (). Like nominate coronata, slightly larger, with longer wing (minimum wing length 73.5 mm in females, 75.5 mm in first-year males, and 78.0 mm in adult males); more streaked below (Alternate-plumaged males) or paler brown (females). Characters broadly clinal where range meets that of nominate coronata; for this reason, hooveri not recognized by Hubbard (). More recently, hooveri maintained as valid (, R. Dickerman and P. Unitt pers. comm.).

(Audubon's Yellow-rumped subspecies appears in photo, below.)

NOTE #2: The International Ornithological Congress (IOC) differs from the AOS assessment of this species. It ALREADY splits the Yellow-rumped Warbler, thereby recognizing Audubon's and Myrtle as two species).

(* = The recent AOS rejection vote against creating additional divisions of the Yellow-rumped complex was based, in part, by several committee members who suggested the need for further genetic analysis and determination of the extent of interbreeding in the subspecies’ contact zones where the “Myrtle” group (coronata), and the “Audubon’s” group (auduboni) mix in western Canada. The status of two other subspecies — “Black-fronted” (nigrifrons), and “Goldman’s” (goldmani) remain unchanged according to at least one taxonomic organization plan.

Black-fronted is a resident in Mexico, and Goldman’s occurs only in southernmost Mexico and Guatemala. Neither of these two subspecies has been observed in the American Birding Association geographical area.

As for why, the IOC considers the Myrtle and Audubon's to represent two distinct species, the following 10 naming rules appear to guide the IOC's reasons for adopting name choices, with one or more the reason why the IOC divides the Yellow-rumped Warbler into two species: Myrtle Yellow-rumped Warbler and Audubon's Yellow-rumped Warbler:

1.            - Each species should have one name only.
2.            - A species name must be unique.
3.            - Anglicized names are acceptable.
4.            - Established names should prevail.
5.            - Local names should not have priority.
6.            - Offensive names should be changed.
7.            - Patronyms are acceptable without bias for or against.
8.            - Simplicity and brevity are virtues.
9.            - Use of the word “island” will be limited.
10.          - Species in the same genus may have different group names.

       For more information, see: