Warbler Guy, how do I ID western warbler songs from each other? Will sonograms of warbler songs help my effort?

Jasper (in Washington state), to help you, check out some western USA warbler sonograms:

http://www.pacifier.com/~mpatters/archive/warbler/sonoguide.html

Using them in combination with audio recording of each species’ song may be a good strategy to successfully “reading” corresponding sonogram for a given species.

Two sound-alike western species sonograms — the Hermit and Black-throated Gray Warbler — are shown here. Where their nesting ranges overlap (e.g., Mendocina County in northern California, among other places), you can sometimes hear them singing in the same forest.

In addition to these sonograms, my solution is to listen carefully when afield. Both species appear to possess dialects that may vary be region. But, for what it’s worth,  

my description of the Hermit’s song is that it’s more wheezy and less articulate/focused than the Black-throated Gray’s.

At http://www.pacifier.com/~mpatters/archive/warbler/sonoguide.html, the author has his own description of how to distinguish each warbler’s song.

In addition: Donald E. Kroodsma’s book “The Singing Life of Birds” provides clues on how to “read” a sonogram as does his chapter “Vocal Behavior in the Cornell Lab of Ornithology produced “Home Study Course” that you can purchase (See:

http://www.birds.cornell.edu/homestudy).

Ultimately, it’s my humble opinion that getting out as often as possible during the breeding season and listening is the best remedy. Simply: What You Sow, Yee Shall Reap by listening carefully each time you’re afield where the warblers sing.

Warbler Guy, which is the most common warbler to see in my suburban wooded backyard near Madison, WI after the peak of migration is over? In the Santa Cruz area where we have a winter home?

The answers for my peripatetic birder friend, Robert, (in Madison), are short and long.

Let’s stay with the brief ones so you can get back to birding outdoors (where I’d rather be now, truthfully (!) )

In Dane Co. where Madison lies, and depending on your yard’s habitat and its nearby vegetational makeup, you can often see Common Yellowthroat (in moist thickets and/or wetland areas where emergents occur), American Redstart (in forests), and Yellow Warbler (also most often in moist thickets and riparian areas).

As for the Santa Cruz area of California, the leading suspects during the non-breeding season (winter) include Townsend’s Warbler (a non-breeding season visitor only), Common Yellowthroat (a resident), and Yellow-rumped Warbler (non-breeding season only), with less likely visits from Hermit, Yellow-breasted Chat, Black-throated Gray, Wilson’s, and Orange-crowned, (with the latter often the most typical “winter” sighting among the final five listed above.

Hope this helps. Now back to our regularly scheduled program, meaning I’m outta here with my binos.

(male Common Yellowthroat,

below/right; photo by
Dan Pancamo)

Warbler Guy, which warbler species are the most likely to mate together to produce hybrid (intergrade) individuals?

Whoa, Jennifer (in Houston): This is not an easy question.

And the answer requires me to put on my professor's cap.

So here goes: 

 Brewster's Warbler (right, above)

Lawrence's Warbler (right, above)

In general, Golden-winged X Blue-winged Warbler intergrades and Hermit X Townsend intergrades are two cases worth mentioning.

In the former, genetic shuffling may result in individuals called Brewster’s Warbler that express field marks from both the Golden-winged and Blue-winged. These hybrids show yellow underparts and a dark throat and head area behind the eye. In most cases, a Brewster’s results from the pairing of a “pure” Golden-winged and “pure” Blue-winged, though, in some cases, a Brewster’s is produced from the crossing of a Golden-winged and Brewster’s.

The Lawrence’s Warbler as a hybrid is less likely when a Golden-winged and Blue-winged mate. That’s because genetic traits involving an understanding of dominant and recessive traits come into play. 

For example, the white underparts of the Golden-winged are considered a dominant trait. So is the reduced head pattern of the Blue-winged. When these two dominant traits are seen in an individual, we call it a Brewster’s expressing the two dominant traits from its Golden-winged/Blue-winged parents.

Recessive traits include the yellow color of the Blue-winged’s underparts and the bold head pattern (throat and head area) of the Golden-winged. Newborns produced from these two types of warblers result in a Lawrence’s. Lawrence’s may also occur from the pairing of two Golden-wingeds expressing recessive genes as their underpart colors or, more rarely, the mating of two Brewster’s Warblers.

Got it? If you’re still with me and understand this explanation, then consider yourself a genius and an ardent warbler fan.

Other warbler species that often create hybrids are crosses between Hermit and Townsend’s Warblers, especially in Washington state. Here the breeding ranges of these two species overlap. In many cases, hybrids between Hermit and Townsend’s express the face pattern of Hermit and the underpart colors of Townsend’s, with the back of hybrid individuals more green than a pure Hermit. In addition, the black on the rear crown of male hybrids extends farther forward than on a pure Townsend’s.

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, which warbler nests farthest north in North America?

{Above graphic citation: Hunt, Pamela D. and Bonita C. Eliason. 1999. Blackpoll Warbler (Setophaga striata), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/431
doi:10.2173/bna.431}

The answer, Justin (in Sheboygan, WI), is the Blackpoll Warbler.

Nesting in boreal spruce and fir forests of Alaska, Canada, and the n.e. USA, the northern-most portion of this common warbler’s range is a vast swath encompassing Alaska (south of the Brooks Range to the base of Alaska Peninsula); the mouth of Mackenzie River (Yukon), and n.-central British Columbia; east through w. and s. Mackenzie, s. Keewatin, and northern portions of Alberta (south to Banff in Canadian Rockies), Saskatchewan and Manitoba (south to roughly 54°N), and Ontario (south to south end of James Bay); to central Quebec (south of Ungava Peninsula), central Labrador, Newfoundland, the Maritime Provinces, and the ne. U.S.

Its most southern latitudinal location (i.e., southeastern portion of its nesting range) is in eastern NY (Adirondacks and Catskills; ne. Massachusetts; Vermont (Green Mtns); and New Hampshire (White Mtns.) n. and se. Maine, se. Quebec (Laurentides Provincial Park to Gaspe Peninsula;; n. and sw. New Brunswick, and sw. and n. Nova Scotia (including Cape Breton I.).

Interestingly, it’s possible an isolated breeding range for this species occurs in n.w. Oregon, based on a 1976 discovery of young in this area.

Which other warblers breed nearly as far north?

The Palm Warbler subspecies known commonly as “Western Palm Warbler” (Setopha palmarium palmarum) nests in habitat corresponding to the distribution of bogs and fens in boreal forests of Canada and the northern United States.

Warbler Guy, when should I expect to begin seeing migrant-arriving Yellow-rumped Warblers?

Gus, in Wisconsin, you should expect this common wood-warbler to vary annually in its arrival time, given the vagaries of spring weather in the Midwest.

Generally, first migrants north of their winter range occur in the Upper Midwest by as early as late March, but greater pulses arrive beginning in early April and soon after. At this time (often when few if any leaves are present on deciduous trees), the Myrtle subspecies of the Yellow-rumps (Setophaga cornonata coronata) often are the most abundant songbird in forest canopies, causing warbler-seeking birders to repeatedly groan “Another Yellow-rump” as they impatiently wait for more diverse forms of Parulidae (wood-warbler family).

Peak movements of Yellow-rumps in the northern US and southern Canada occur from late April through mid-May. Like many songbird species, male Yellow-rumps migrate earlier than females, averaging 4 to 7 days sooner in their arrival upon breeding grounds.

Keep in mind that some hardy Yellow-rumped Warbler individuals remain throughout the non-breeding season in the Upper Midwest, especially during warmer winters.

As for the typically more West Coast breeding Audubon's subspecies Yellow-rumped (Setophaga cornonata auduboni), its migration dynamic shall be discussed in an upcoming article.

Fab Five Warbler Photo Quiz #7

From top to bottom, can you ID the following wood-warblers? Look for the answer in March when I post a new article.