Why I disobey Roger Tory Peterson

Puget Sound White-crowned Sparrow, one of 3 subspecies of White-crowned Sparrows in the Pacific NW, and one of 5 subspecies in North America--all easy to tell apart, Newport, Oregon, 15 September 2008 by Greg Gillson.

 

"Subspecies have no definite entity, but merely represent subdivisions within the geographic range of a species. They are races, usually determined by morphological characteristics such as slight differences in measurements, shades of color, etc. These subdivisions, generally discernible only by comparison of museum series, are seldom apparent in the field and should not concern the field observer.... No one but an expert comparing specimens would detect the difference. So forget about subspecies."
Roger Tory Peterson
A Field Guide to Western Birds. 1969.

My 1969 Peterson Field Guide is well worn. The pages and binding are barely held together with several types of tape. Every page of that treasured "obsolete" field guide has annotations--new birds added to the North American list, key field marks underlined, changes in bird's names, additional ID pointers and my personal voice descriptions added in the margins.

That field guide is also full of annotations of "lumps" of formerly considered full species into subspecies, as well as "splits" of formerly considered subspecies into full species.

Just paging through, here are some that I recorded or remember....

Pacific Loon split from Arctic Loon
Clark's Grebe split from Western Grebe
Black-vented Shearwater split from Manx Shearwater
Nazca Booby split from Masked Booby
Green Heron lumped with Striated Heron to form Green-backed Heron
Green Heron and Striated Heron split from Green-backed Heron
Bewick's Swan and Whistling Swan lumped into Tundra Swan
Cackling Goose split from Canada Goose
Common Teal lumped with Green-winged Teal (America's only)
Black Scoter split from Common Scoter
White-tailed Kite lumped with Black-shouldered Kite
White-tailed Kite split from Black-shouldered Kite
Harlan's Hawk lumped with Red-tailed Hawk
Blue Grouse split into Sooty Grouse and Dusky Grouse
Lesser Golden Plover split into Pacific Golden-Plover and American Golden-Plover
Wilson's Snipe lumped with Common Snipe
Wilson's Snipe split from Common Snipe
Yellow-footed Gull split from Western Gull
Thayer's Gull split from Herring Gull
Long-billed Murrelet split from Marbled Murrelet
Screech Owl split into Western Screech-Owl and Eastern Screech-Owl
Whip-Poor-Will split into Eastern Whip-Poor-Will and Mexican Whip-Poor-Will
Red-shafted Flicker, Yellow-shafted Flicker, and Gilded Flicker lumped into Common Flicker
Common Flicker split into Northern Flicker and Gilded Flicker
Red-naped Sapsucker and Red-breasted Sapsucker split from Yellow-bellied Sapsucker
Couch's Kingbird split from Tropical Kingbird
Traill's Flycatcher split into Willow Flycatcher and Alder Flycatcher
Western Flycatcher split into Pacific-slope Flycatcher and Cordilleran Flycatcher
Scrub Jay split into Western Scrub-Jay, Florida Scrub-Jay, and Island Scrub-Jay
Plain Titmouse split into Oak Titmouse and Juniper Titmouse
Brown-throated Wren lumped into House Wren
Winter Wren split into Eastern Winter Wren, Pacific Wren, and Eurasian Wren
Bicknell's Thrush split from Gray-cheeked Thrush
Solitary Vireo split into Cassin's Vireo, Blue-headed Vireo, and Plumbeous Vireo
Myrtle Warbler and Audubon's Warbler lumped into Yellow-rumped Warbler
Bullock's Oriole and Baltimore Oriole lumped into Northern Oriole
Northern Oriole split into Baltimore Oriole and Bullock's Oriole
Great-tailed Grackle split from Boat-tailed Grackle
Gray-crowned Rosy Finch, Black Rosy Finch, and Brown-capped Rosy Finch lumped into Rosy-Finch
Rosy-Finch split into Gray-crowned Rosy-Finch, Black Rosy-Finch, and Brown-capped Rosy-Finch
Rufous-sided Towhee split into Spotted Towhee and Eastern Towhee
Brown Towhee split into California Towhee and Canyon Towhee
Oregon Junco, White-winged Junco, Gray-headed Junco, and Slate-colored Junco lumped into Dark-eyed Junco

If subspecies "have no definite entity" and differences "are seldom apparent in the field," then why were 36 of these non-entities turned into full species, complete with definite field identification characters?

On average, since I began birding in 1972, nearly one subspecies per year in North America has magically become a species from its former status as a non-entity!

Frankly, there are many more subspecies that will likely become full species in the near future. Splits are likely to come from within Warbling Vireos, Fox Sparrows, Marsh Wrens, Yellow-rumped Warblers (again), Western Scrub-Jays (further), Leach's Storm-Petrels, and more.

So, though I respect what Peterson started, please forgive me if I disobey his advice on this topic and continue to identify White-crowned Sparrow or Canada Goose subspecies or Fox Sparrow groups when I am just as sure of them as I am of Clark's Grebes, Black-vented Shearwaters, Western Scrub-Jays, Red-breasted Sapsuckers, and Spotted Towhees--all former subspecies. [See David Sibley's list of field identifiable subspecies.]

And please pardon me when I take notice and document subspecific variation in Song Sparrows, Savannah Sparrows, or Spotted Towhees--even if I can't tell for sure what subspecies they are. After all, such exercises help improve my identification and observational skills.

Peterson would approve of that.

A tale of two White-crowned Sparrows

Gambel's White-crowned Sparrow, Fernhill Wetlands, Forest Grove, Oregon on 16 April 2010 by Greg Gillson. Notice bright white head stripes, pale stripes on back, orange bill, clean gray underparts.

 

White-crowned Sparrows are moving through the Pacific Northwest right now. I photographed this bird recently in NW Oregon.

As discussed last year (In the backyard... White-crowned Sparrow), there are 5 populations across North America.

West of the Cascades, from SW British Columbia to NW California, these represent two populations. The Puget Sound White-crowned Sparrow nests in this area and is now moving into breeding habitats--coastal headlands, valley pastures, and western Cascade clear-cuts.

On a broad band across the west, the Gambel's White-crowned Sparrow is also migrating north now. It will breed in interior British Columbia, western Alberta, and Alaska.

These birds sing during migration. The songs of the various populations across North America are different. Indeed, songs can be slightly different even within populations, as young birds learn to sing whatever local dialect they hear.


Puget Sound White-crowned Sparrow, Hayward, Oregon on 16 May 2008 by Greg Gillson. Notice dingy white head stripes, dull two-tone brown back, yellow bill, brownish sides.

 


If you want to practice separating songs, now is the time.

I transcribe the "typical" song of Puget Sound White-crowned Sparrow as a lively and sweet:

wee SWEE chilly-chilly-SWEEE cheer-cher-er

On the other hand, the song of the Gambel's White-crowned Sparrow is more mournful, with downward-sliding emphasized notes:

WEE chur chilly-chilly-CHUR

The White-crownd Sparrow songs on the Cornell Lab's online field guide are not exactly the songs I usually hear in NW Oregon, but close enough.

The song marked as "Alaska August 2006 by Geritt Vyn" is a Gambel's.

The song marked as "Oregon June 1988 Geoffery A. Keller" is a Puget Sound.

A note on field guides.

Sibley has a "Pacific" form that includes Puget Sound White-crown and the non-migratory Nuttall's form of the central California coast. The "Interior West" is the Mountain White-crown. "West Taiga" is Gambel's. "East Taiga" is the nominate leucophrys subspecies.

The National Geographic guide shows the dark-lored, pink-billed as leucophrys (includes Mountain White-crown). The pale-lored birds are split between the bright Gambel's with orange bill and the duller and browner Nuttall's with yellow bill (includes Puget Sound White-crown).

Confused? I hope not. But you can practice again in September when the birds migrate south.... Or, eastward from the Cascades practice looking for the dark-lored Mountain White-crowned among the more abundant Gambel's....

In the backyard... White-crowned Sparrow

White-crowned Sparrow, Timber, Washington County, Oregon on 28 June 2008 by Greg Gillson.

 

The handsome White-crowned Sparrow is not overly common at backyard feeders in the Pacific Northwest in winter. But migrant birds pass through in April and September, often visiting backyard feeders in good numbers. West of the Cascades and especially along the coast these are common summer birds.

But this is an over-simplification of a fascinating population dynamic. If you look at the range map of White-crowned Sparrow in North America, you'll see birds breed from Newfoundland and across northern Canada through Alaska. From there they breed in the Rocky Mountains to northern Arizona and New Mexico, and also along the West Coast to southern California. Northern birds winter to the south, to the central latitudes of the interior US, along both US coasts, and into Mexico.

Ornithologists divide the White-crowned Sparrow into 5 populations. Each has a slightly different range, plumage, and song.

It is a bit complicated, but in the Pacific Northwest the birds breeding in the Rocky Mountains and mountains in the Great Basin are the "Mountain White-crowned Sparrow." This form has black lores (feathers between the bill and eye). All other regular forms in the Pacific Northwest have pale lores. They depart for southern regions in winter.

Spring (April) and fall migrants and occasional wintering birds, primarily east of the Cascades, are the "Gambel's" form nesting in Alaska. These winter in the deserts of the American Southwest and into Mexico.

West of the Cascades from southern British Columbia to northwestern California breeds the "Puget Sound" form (as photographed above). Some birds remain to winter, but most migrate south into southern California.

From Mendocino County, California, south along the immediate coast lives the non-migratory "Nuttall's White-crowned Sparrow".

Many of the birds in fall and winter are immatures with rusty brown and white stripes, rather than black and white. These young birds can be confused with immature Golden-crowned Sparrows. Likewise, the rather rare-in-the-West White-throated Sparrow is very similar, but with a blackish bill and white throat clearly set off from a grayish breast.

White-crowned Sparrows eat black oil sunflowers and other seeds at your backyard feeder. This may allow you to examine them more closely, perhaps noticing differences related to age or population as discussed above. For more details see especially the National Geographic Field Guide to the Birds of North America.

In the backyard... Golden-crowned Sparrow

Golden-crowned Sparrow, Tualatin Hills Nature Park, Beaverton, Oregon on 13 March 2009 by Greg Gillson.

 

For most of the fall and winter this large sparrow occurs in rather drab plumage. The first year birds show a diffuse yellow forehead and brownish crown. Winter adults aren't much brighter. But, then, beginning in March (as in the photo above), the birds develop the wide black lateral crown stripe with the golden yellow median for which this bird is named. The birds begin singing in spring, as they make their way north into the mountains. Their song is a three-note plaintive whistle in descending notes, weee peee peer, which some render quite appropriately as: "oh dear me."

In fall and winter, first year Golden-crowned Sparrows might be confused with first year White-crowned Sparrows. However, the White-crowned Sparrows have a more definite brown lateral crown stripe and pale center crown stripe. Also note that the upper mandible of the bill of Golden-crowned Sparrow is dark, while the bill of White-crowned Sparrow is yellow or pink.

Golden-crowned Sparrows breed in willow bogs and dwarf conifers at or above timberline in mountains from western Alaska and Yukon south to southern British Columbia and southwestern Alberta, rarely in the extreme northern Cascades of Washington state.

In winter, birds occur from coastal southeastern Alaska south, primarily west of the Cascades and Sierra Nevadas, in lesser numbers to northern Baja California. They are found in brush piles, blackberry tangles, and deciduous woodland edges, as well as in residential areas with similar dense brushy edges.

They are more widespread in migration, occurring in towns in the Great Basin deserts and mountain foothills to southeastern Idaho, though in much diminished numbers.

Their primary foods are seeds and plant material. The bird in the photo above is eating the new buds of Oregon Grape. They are attracted to backyard bird feeders from September to April.