spring migrants because of the Region’s geo- 
graphical complexity and the difficulty of 
teasing apart truly early spring arrivals from 
birds that wintered locally but went undetect- 
ed during the winter.” 
So just as we recognize that many winter- 
ing birds (or birds that attempt to winter) out 
of range were often “reverse” migrants in au- 
tumn, so perhaps some of our off-course 
spring migrants were merely birds that win- 
tered in an unconventional location, some of 
these certainly, or perhaps, autumn vagrants. 
If we think about the case of Rufous Hum- 
mingbird, which winters by the hundreds in 
the Southeast but was nearly a vagrant there 
30 years ago, it can be difficult to imagine the 
process by which “rarity” became “regular.” 
Food resources and winter survivorship were 
surely key to the steady increase and rapid 
change in nonbreeding range. And nowadays, 
flyby Selasphorus at coastal Atlantic migration 
sites, even in August and September, are not 
unheard of. Such is the process by which a 
westerner becomes an easterner. 
Returning to tanagers, we might ask: what 
if some of these spring Western Tanagers 
(some of them adult males) are returning to 
winter again in Gulf coastal states? If so, then 
again, they probably aren’t best considered 
“vagrants” when intercepted in spring in the 
Midwest or in Ontario: they are low-level mi- 
grants. And what of Summer Tanager, a 
species that was found in droves (48!) in the 
Western Great Lakes this spring, that de- 
served an “S.A. Box” in the Prairie Provinces 
regional report (where it has become an al- 
most-regular rarity), and that features promi- 
nently in this issue’s lead article? Appear- 
ances of this species have increased rapidly at 
the northern boundary of its breeding range, 
and records continue to accumulate, more 
slowly and unevenly, at feeders in southeast- 
ern North America in winter. How does one 
account for a Summer Tanager 28 March in 
Orleans, Massachusetts this spring? Was it an 
early fallout bird that departed the tropics far 
too early and found itself over open ocean 
until it reached Cape Cod? Or did the bird 
winter somewhere in eastern North America 
and begin to forage away from its favorite 
feeder as the weather warmed? Neither ex- 
planation seems satisfying or intuitive at first. 
But consider Alaska’s wintering Orange- 
crowned Warblers. Thede Tobish writes of 
one that wintered in Kodiak through this past 
season that it “remained at its favored site 
through 8 March. This is a typical pattern for 
rare passerines that manage to survive a win- 
ter, usually at a coastal feeder, in that they all 
end up departing their food source well 
ahead of what is the otherwise normal arrival 
period for that species — i.e., they nearly al- 
ways leave a winter site between early March 
and early April, to go who knows where.” So 
a Summer Tanager in late March in coastal 
Massachusetts could be something very dif- 
ferent from the Summer Tanager that shows 
up in leafless trees in Nova Scotia just a week 
later. When considering these birds north, or 
east, of range, we should resist the tempta- 
tion to produce patterns among records of 
birds that are possibly disparate in their con- 
tributing factors. 
Before we attempt to speculate further, let’s 
look at other western birds east of normal in 
spring 2009 and ponder the question: Were 
these birds blown off course by (south)west- 
erly winds on their otherwise normal migra- 
tion, or were they moving back toward typical 
breeding range after wintering a bit east of 
usual areas or even in an extralimital setting? 
Let’s tackle the mostly patternless records 
first. Many “singular” western vagrants in 
the Plains, Midwest, and East in spring are 
species whose migration is not terribly epic 
but rather gradual or at least not long-dis- 
tance. Some of these species do winter in the 
tropics, but many can “overwinter” in the 
United States, either in the border states or 
the next tier of states to the north. The only 
species in this cadre that may begin to show 
a pattern is Lesser Goldfinch, which seems 
to be increasing as a vagrant on all fronts 
and is clearly expanding its range northward 
in the West. A black-backed male attended 
feeders in Beaufort, North Carolina 2-4 
March, furnishing one of very few records 
for the East, but most of the records are re- 
cent. A Violet-green Swallow near Hawar- 
den, Iowa 14 May was the state’s first. For 
those who think of Iowa as being way out 
west, well ... the birds do not necessarily 
agree: birds from the far West are not abun- 
dantly represented in the Iowa avifaunal 
record as vagrants. Flycatchers from the 
West ignored the Midwest and East this 
spring; a Say’s Phoebe in Astatula, Ohio 12 
March and another in Cape May, New Jersey 
30 April through 2 May were exceptions. 
Scissor-tailed Elycatchers, which breed mar- 
ginally in the southern Midwest and the 
Southeast (and winter by the dozens per site 
in Florida), were few in the East this spring, 
but who considers these “western” vagrants 
any longer? A Rock Wren in Jefferson Coun- 
ty, Kentucky 1 1 May was only the state’s sec- 
ond and certainly notable, if not a champion 
Neotropical migrant (these hardy birds 
VOlUME 63 (2009) • NUMBER 3 
THE CHANGING SEASONS: OSCILLATIONS 
could probably hang on through a local win- 
ter, though more likely this was a bird that 
wintered a bit farther south). The usual 
smattering of western warblers included sin- 
gle Townsend’s Warblers at Prospect Park, 
Brooklyn, New York 25 April, at Rondeau 
Provincial Park, Ontario 8 May, and at Cap 
Tourmente, Quebec 17 May; two Audubon’s 
Warblers in Maryland 2 March and 19 April 
and one in Ontario 10 May; and a Black- 
throated Gray Warbler in southern Florida 7 
March. Certainly, any of these birds could 
have wintered in the East or Southeast, and 
the Maryland and Elorida birds almost cer- 
tainly did. The Green-tailed Towhee at Had- 
den, New Jersey was a wintering bird that 
stayed through 3 May, and a Gray-crowned 
Rosy-Finch in St. Louis County, Minnesota 
17 March may well have been a northbound 
migrant but was just one state east of typical 
winter range. A female Bullock’s Oriole in 
Tallahassee, Florida 10 March was in a loca- 
tion “where the species occasionally win- 
ters,” according to Bruce Anderson and 
Andy Bankert. No Bullock’s Orioles were re- 
ported in the East otherwise this spring. 
Quebec had two of the cutting-edge “west- 
ern” vagrants this spring: a Hooded Oriole at 
Macamic 30 May-2 June, and a Black-capped 
Vireo at Pointe-aux-Outardes 24 May, each 
representing a third record for Canada. Pierre 
Bannon, Olivier Barden, Normand David, 
Samuel Denault, and Yves Aubry write: “In 
late May, strong westerly winds were associat- 
ed with some spectacular diurnal migrations 
of warblers flying windward almost at ground 
level on the North Shore. But these strong 
winds were probably not the ultimate cause 
for the appearance of some extreme rarities 
like Black-capped Vireo and Hooded Oriole.” 
Presumably, these birds belong to a class we 
call “overshoots” in spring, often found dur- 
ing warm spells, but when birds are thou- 
sands of kilometers beyond the northern edge 
of their breeding ranges, they were almost 
certainly not simply displaced by a weather 
system. Although the vireo and oriole are 
“western” species to most easterners, their ap- 
pearances in southern Canada would place 
them arguably in this essay’s next section, the 
inevitable “Southern Birds North.” 
Before we pass from the more singular rari- 
ties to the more widespread, we should con- 
sider several remarkable records of those enig- 
matic nonpasserines, the swifts, this season. 
For easterners who assume that all western 
states have at least a handful of substantiated 
records of Vaux’s Swift, think again: reports 
from Colorado 1 May and Texas 16 April 
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