THE CHAN ING EASONS Dale A. an*

er dar &s !acer n o_ea-st:rn

' auta • • ot• vrtt•, ve Is • Dotterel, Farallon Island& Sept., 1974. Photo / Pieter S. Mverx from P.R.B.O.

"This has to be the most exciting fall seasonon servershad not taken time to recordtheir imp•s- record" wrote Guy McCaskie of autumn, 1974,in sionsof Golden-crowned Kinglets in each •gion Southern California. While not all Regional we would have no idea of the virtually nation- Editors solabeled it, avian activity in many areas wide i•uption of the speciesthis year. Here in the was intense, intriguing and complex. Their re- West, the outstanding event was the easte• ports reflect' observationson an overwhelming wood warbler invasion, and •fities produced number of species. (Over 430 were recorded in considerable excitement in Texas and Alaska. McCaskie's region alone!) This fall, as always, Taxonomic comment • Now elevated to there is good news and bad, reports of great specific status, Thayer's Gulls miraculouslyap- movements and minor ones; and there are the pear. Westward, the few reports of "Yellow- usual enigmas. But underlying all is the truism shafted" Flickers and "Slate-colored" Juncos that nothing in nature remains static. Change is may reflect lessenedobserver inte•st following omnipresent, and seriousobservers can materi- recent taxonomic sh•ts. The s•cies rem•ns the ally aid in monitoringthe fluctuations.I'd like to soletaxon of importanceto manybirders, despite issue a plea for more follow-up information on some readily identifiable subspecific pheno- previousseasons' important finds and population types. "Great White" Herons evidentlyare spec- figures. (Where did all those White-tailed Kites tacular enoughto provide an exception. go? Were there no Peregrinesthis year on the M&ration hazards • Interesting obse•ations Texas coast which boasted 400 sightings last on low altitude migrant flight are given by pilot fall?) Unevennessin reporting is a problem, but Robert Coggeshallin the Southe• Great Plains bird activity variestremendously too. Even in the Region. In placesbirds didn't fly high enough. comparativelysmall SouthTexas Region, Editor TV towers claimed thousands of victims this fall Fred Webster writes that all localities tell a in at least nine states and two Canadianprov- slightlydifferent story this fall. And GeorgeHall inces. A dark 600-foot stack on the giant new detailsthe vastly different resultsfrom two large Phelps-Dodgesmelter in southwestNew Mexico banding stations only 90 miles apart in the Ap- killed 150passerines Sept. 18, introducinghazard palachianRegion. How different our interpreta- into a heretofore safe (and clean) piece of air- tion might be if we had data from only one of those two spots. Local happeningsmay or may not reflect what goes on elsewhere; we never *Department of Biological Science, Western New Mex- know until all the reports are in. If so many ob- ico University, Silver City, N. Mex. 88061.

Volume 29, Number I 23 space. One wonders whether Manitoba's warbler graphed in British Columbia prompted disaster of last spring was responsible for the emergence of a 1972 record from Washington "disappointing" parulid passagethere this fall. Key West again had Lesser Black-backed Gulls White-winged Black Terns remained in the Mid- RARITIES dle Atlantic Coast Region, and Alabama's first Regionally, first place for exotic occurrences Noddy Tern was found on Dauphin Island once more would go to our northernmost state. Perhaps not all those "Caribbean" Coots should Gibson's and Byrd's Alaskan summaryagain has be consideredas such; see the Florida report a decided Palaearctic flavor. A few years ago Incongruous for a place reporting Barrow's we'd not have imagineda regionalreport in which Goldeneyes, Las Vegas, Nev., also had a Com- Whooper Swansdid not merit boldfacetype. This mon Ground Dove. Groove-billedAnis appeared season's account embraces seven species not in Arizona, Nevada, California and east to listed in Birds of North America (Robbins et al. Florida. A Buff-bellied Hummingbird was photo- 1966), bringing to at least 16 the number of such graphed in New Orleans. Almost unbelievable is birds recorded from Alaska in 1974; nine are not the report of a Golden-fronted Woodpecker in treated even in the "accidentals" section of northern Michigan. One was reported from Peterson's western guide. Yet many of the re- Florida too, but so was a xanthochroistic Red- cently reported Asiatic shorebirds may appear bellled Woodpecker,prompting exceptional cau- annually in the Aleutians. September also tion in extralimitalidentifications ofC. aurifrons brought a true accidental -- North America's A Tropical Kingbird strayed to Florida, a Gray first Marsh Sandpiper (Tringa stagnatilis). Kingbird to Connecticut, but more surprising Among other regions, South Texas ranks high were the thick-billed Kingbirds at San Francisco with two apparent White-collared Swifts (Strep- and on Vancouver Island. A Sulphur-belhed toprocne zonaris) near Rockport, two Black- Flycatcher was new to California. Wheatears vis- crestedCoquettes (Paphosia helenae) at Corpus ited Quebec, New Jersey and Virginia. Both Christi and more of these tropical hummers re- Red-throated and Sprague's Pipits showed in ported from Edinburg. A Rufous-tailed Hum- southern California. Yellow-green Vireos were mingbird at Brownsville and a Golden- reported there and (lesspositively) from Arizona crowned Warbler in Starr County were but the Smith's Longspurs again appeared in Colorado second A.O.U. area records of their speciesin and one was collected for New York's first rec- the 20th century. Texas' Brown Jaysnow number ord. 25-40. The Middle Pacific Coast Region contri- buted a Dotterel and a White Wagtail, both rec- POPULATION TRENDS ords substantiated photographically. Grebes through Ibises -- Horned Grebes were Among the many lesser rarities are a few de- unusually numerous in the Middlewestern servingspecial mention. Note that, in addition to Prairie, Southwest and Southern Great Plains the aforementioned Mexican forms, numerous Regions. Eared Grebes, normally common out other southern landbirds strayed northward. West, were down almost everywhere except on Among exciting pelagicswere two Black-browed the Pacific Coast. In southern New Mexico Albatrosses off Cape May and a probable one Horned Grebes outnumbered Eareds two to one, near e. Florida, Harcourt's (Band-rumped) a surprising turn of events. Possibly the Eared Storm-Petreloff Florida, 6 Black-cappedPetrels Grebes shiftedto the Central SouthernRegion's off Cape Hatteras, and Manx Shearwatersin both waterways where there were many reports Florida and Maryland waters. Westward, New Western Grebe numbers were good. From Zealand (Buller's) Shearwaters appeared in Florida we learn that Cory's Shearwater, not the Alaskan territory and there were record numbers Greater, is proving to be the most common off California. A Little Blue Heron astride the Puffinus off the peninsula's east coast. White international boundary contributed to both the Pelicansnested in numberscomparable to 1973's British Columbia and Washington lists. There at Great Salt Lake but lost ground in places were reports of Wandering Tattlers in Arizona Brown Pelican observations from the Southern and Utah (though an earlier "tattler" near Tuc- Atlantic Coast Region indicate slow recovery of son turned out to be a Spotted Sandpiper). Other the population there. Alabama also had en- shorebirds of note included a Rufous-necked couraging counts, but the species remained Sandpiper at the Salton Sea, Curlew Sandpipers scarce in Florida. Fairly good numbers were re- in Quebec, Connecticut, New York and Califor- ported from the Middle Pacific Coast, with the nia, Bar-tailed Godwits on both coasts, and nu- percentageof immatures varying locally from 25 merous Ruffs. Mew Gulls were seen in New Jer- to 40%. Farther north, half of the pelicans on sey and Virginia. The Black-headed Gull photo- Tillamook Bay were immatures. There is so little

24 AmericanB•rds, February, 1975 good news of Double-crested Cormorants that a cent Arizona; a good proportion of those seen southbound movement of 14,000 off North were immatures. Single Swallow-tailed Kites nn Carolina certainly is welcome. Similarly out- Texas were noteworthy, as was the one at Cum- standing in a generally poor-to-mediocre heron berland, Md. -- first for the Alleghenies since pncture is a report of several thousand Green 1908. The only White-tailed Kites reported were Herons moving at night over one W. Virginia two Floridian birds. In the Southern Great Planns, locality. The White-faced Ibis is rapidly declining FrancesWilliams reportedRed-tailed and Marsh nn Nevada and Utah. Hawks "abundant" -- a term seldom associated Waterfowl -- Swans did very well, especially with these speciestoday. They were fairly com- nn Alaska, although Trumpeters fared poorly in mon in parts of the Southwest, with gratifying South Dakota where breeding ponds dried up. numbers of immature harriers. But in southwest Mountain West Editor Hugh Kingery in effect New Mexico and southeast Arizona, where for- questions the policy in cemain western states of merly a large proportion of autumn Red-taileds open seasonson Whistling Swans while espous- were young birds, recent years have shown a nngprotection of the few Trumpeters. Is there a discouragingreversal. This fall we found only legitimate excuse for the hunting of swans any- one immature for every eight or nine adults Is where in America? Black Brant producedessen- this happeningelsewhere? Red-shouldereds gen- tnallyno young last summer.Snow Goose reports erally remained scarce, but they may be expand- were mixed, with low numbers in Alaska but ing their Californianrange. Both this speciesand good countsfrom the Yukon. Some 30 per cent of the Red-tail reportedly are "doing well" in the 100,000 Snows in Nebraska were immature, but a Appalachian Region where George Hall con- group in Br. Columbia were said to be "virtually tinuesto note apparentimprovement in the over- all adult birds" and but one per cent of the Salton all hawk picture. It is also hearteningto hear of a Sea flock were young. Canada Goose numbers goodhawk seasonin the Ontario and Hudson-St were down in the Northwest but set a record high Lawrence Regions.This was the best autumn of nn New York. Mallards are doing exceptionally 18 at the Montclair, N.J., hawk lookout, wnth well. The continue to replace Black Ducks in the 9000 more raptors than any previous year. Most Northeast. Pintails, Ring-necked Ducks and sightings there were of Broad-winged Hawks Redheads all enjoyed fairly heavy flights in the which may be more than holding their own. At West, and there were some faintly encouraging least 85,000 Broad-wingedswere reported across sngnsin Canvasback numbers. Despite good the country this fall. A large mid-September counts from Wisconsin to Missouri, Vernon movement in Illinois, and the massive flights nn Kleen tells us half of the Canvasbackpopulation the Central Southern and Southern Texas Re- nsthreatened by industrialpollution in the upper gionsSept. 20-22, may have involved someof the MnssissippiRiver. A phenomenal 1500Barrow's sameflocks. In Texas their movementsdefinitely Goldeneyes in Washington preceded record were correlated with advancing cold fronts. At numbers farther south to be dealt with in the San Francisco's Pt. Diablo, Laurence Binford wnntersummary. Oldsquaws, Harlequin Dicks, observed 30 migrating Broad-wingeds, two of scotersand Hooded Mergansersall seemedto be which were of the extremely rare dark phase--as present in more places, in higher numbers or was one of the 18 birds he saw there in 1972 both. Ruddy Ducks are decreasingin the Moun- These hawks may represent some far western tran West -- possibly eastward as well. breeding population. I believe most records of this species' melanistic phase are from the West, Diurnal Raptors -- An unusuallyheavy Accip- additional information would be welcome. Fer- tter migration occurred in Alberta. At Duluth, ruginousHawks increasedin the Southwestand Mnnn., Goshawks were below the last two years' Southern Pacific Coast Regions but were less epncnumbers but neverthelessreached 1300this numerous farther north. Swainson's Hawk fall, and there were numerous reports from the flights seemed normal for recent years. Appalachian Region. Western observers saw few. Cooper's Hawks unexpectedly outnum- Bald Eagle numbers suggesta poor breednng bered Sharp-shins in some areas. On balance, season although few reports contain age data both speciesmade a reasonableshowing in the Two large groups were reported: 100 in Britnsh East, with especiallygood Sharp-shinned counts Columbia and 359 in Glacier National Park. Only nnOntario and along the coast. Cooper's Hawks 109 iramatureswere among the latter- below evidently remained scarcein the Southern Great last year' s 117young birds in a total of 157eagles Plains. The Southwest Region's report implied a Except in some mid-continent areas the ratio of poorAccipiter showingin New Mexico, but the youngto adults was low. This was especiallytrue two smaller specieswere in at leastnormal num- in the East where only one immature (of 17 bers through the southern counties and in adja- eagles) was seen from Hawk Mountain, and

Volume 29, Number 1 25 another single (of 14 birds) along the southern Great Lakes. Long-taileds appeared in Missouri Atlantic Coast. Golden Eaglesmay be increasing and Arkansas. •n the Midwest. Hawk Mountain reported 33, the Cranes, Shorebirds -- Of 15 young Whooping Appalachian Region 26. Out west the few data Cranes produced in Canada only two made •t to submitted reflect no patterns. Texas along with 47 adults. Low-to-usual Sand- A few Gyrfalcons appeared in northern areas hill Crane numbers were reported from several acrossthe continent. Three regions experienced places, and nothing like last year's big flocks local increasesin Peregrines. However, despite were seen in the northern Great Plains. No fig- high interest in this falcon fewer than 230 sight- ures were reported from important New Mexican ingswere reported-- far below last year' s figure. refugeswhich normally host thousandsof cranes Few reporters seem to have heeded Kenneth Large numbers of Sharp-tailed Sandpipersap- Able's appeal for age data on Peregrines. We peared in the Northwest. Sightings of Buff- don't know to what extent our remaining birds breasted Sandpipers were fewer than last fall but are reproducing (though the scanty total may it- still there were encouragingreports of both this self provide the answer). Merlin numbers, up a species and the Hudsonian Godwit. Baird's year ago, crashed alarmingly. Reports at hand Sandpipersevidently ahd a very good year. Red show only 34 recorded in the East, apart from Phalaropeswere recordedin numerouslocalities Florida where, however, the species was out- numberedby Peregrines.Among all regionsfrom the plains to the Pacific I can account for only 50 STATUS CHANGES AND RANGE EXTEN- Merlins, excluding the Middle Pacific Coast SIONS where these and Peregrines were "well re- Brandt's and Red-faced Cormorants nested ported." American Kestrels, scarcely mentioned again in Prince William Sound, Alaska, the latter by many reporters, did well in the Mountain West species colonizing four more islands. Cattle and Southwest. Prairie Falcons received little Egrets reached British Columbia, and they ap- comment. Osprey numbers were lower than last peared "in force" in Colorado for the first time yeaifs (very low on the Middle Pacific Coast), Either the Monk Parakeet or its novelty is dwin- except for possibleslight increasesfrom the Mr. dling; only five birds were mentioned this fall West to the Appalachian Regions. Anna's Hummingbird pressed onward in Col- Owls -- We receive few data on Barn Owls, orado, across New Mexico to Midland, Texas, hence great interest centers around the flight at but no records came from the Rockport area Cape May. The Screech Owl, once common in so which reported them so freely not long ago many areas, now rarely has its name printed in Again there was an influx of Anna's Hummers our pages. This fall, records of it tripled in the into the Northern Pacific Coast Region, and the Mountain West. Flammulated and Spotted Owls species' continued presence in Alaska is indeed both bred at Zion National Park. There were two remarkable. Red-bellied Woodpeckers are per- or three pairs of the latter, bringing a little good manently established in Colorado where they news of this splendidcreature which is disappear- push northwestward. Colorado's Blue Jays ap- •ng from so many of our mountaincanyons. Both pear there to stay, and some day we may have to Barn and Great Horned Owls staged a comeback refer to the "Common Jay" if Blues and Steller's in southwest New Mexico and southeast Arizona continue to hybridize as they do at Boulder. Blue where populations have been low for several Jays moved westward in Colorado and on to years. In the Appalachians, Barred and Great Washington and Br. Columbia. Carolina Wrens Horned Owls were found more frequently than continued to occupy new territory. The oppor- usual. It would be pleasant to think that owls as tunistic Great-tailed Grackle evidently nested •n well as their diurnal counterpartsare beginningto Nevada and further explored in New Mexico and increase. Colorado. Larids, Jaegers -- Little Gulls were reported in several inland localities and on both coasts. IRRUPTIONS Franklin's Gulls are swiftly recovering from the Rough-leggedHawks invaded widely, some crash of 1972-73. The only "large" count of Least reachingsouthern New Mexico by mid-October Terns (600) came from Padre Island, Texas; the while numbers were still moving through specieswas reportedmore often than usualin the Michiganin late November. There were fewer on southernGreat Plains.It was a goodjaeger sea- the Pacific Coast than last year, however. Snowy son in the Middle Pacific Coast Region. Inland, Owls, scarce in the West, were building up to a probableor idenifiedParasitic Jaegers were seen notable invasion farther east. Near Duluth, in Alberta, Montana, and Arizona. At least 45 Minn., 300 Saw-whet Owls were banded, and a jaegers, mostly Parasitic, were noted near the noticeable movement occurred through the Mid-

26 American Birds, February, 1975 diewestern Prairie Region. Smaller numbers Orioles of the race galbula were seen in New were banded at Cape May, and a few reached Mexico, California and Oregon. Nevada received Virginia and Arkansas. Both three-toed wood- its first PaintedBunting. There were Sharp-taded peckerswere sightedrather often coast-to-coast, and Le Conte's Sparrowsin California again, and and Red-breasted Nuthatches were very wide- a Sharp-tailed provided a provincial and regional spread. Kinglets, too, especially the Golden- "first" in British Columbia. Washington's sec- crowned, attracted attention almosteverywhere. ond Swamp Sparrow was of interest in view of 30 The latter reachedat least minor invasionpropor- reported from central California. Unprecedented tions from the southern Pacific Coast (on the longspur numbers reached the Pacific. Channel Islands for the first time) to the lower Rio Grande Valley. A Winter Wren reached the THE GREAT WARBLER INVASION Channel Islands too. This species invaded east-' The spring of 1974 witnessed an impressive ern Colorado and was relatively plentiful else- surge of predominantly eastern wood warblers where. Veeries received comment from several into the West -- 18 species in all. Scarcely three editors because of large numbers, early or late months later there followed a veritable explosion dates, or as a first documented state record of eastern parulids, with 25 species-- many in (California). Numbers of Mountain Bluebirdsoc- unprecedentednumbers -- reachingthe Pacific curred from Alaska to the Southwest; several Virginia's, Lucy's .and Red-faced Warblers, and placesreported them abundantin contrast to last the Painted Redstart also appeared in California year. Philadelphia Vireos seemed more numer- The Middle Pacific Coast recorded 652 individual ous than usual, making news from Florida to vagrantwarblers, providing the most spectacular Oklahoma. Red Crossbillsfailed to irrupt despite invasion on record to quote Regional Editors a few false alarms like the birds in Amarillo, Stallcup, De Sante and Greenburg. In both Texas, Aug. 23. White-winged Crossbills re- coastal California regions the now usual eastern mainedcommon in parts of the northern Rockies, species appeared in larger than expected num- and they were sporadic in the Northeast. bers, and 5 or 6 of truly rare occurrence turned "Winter finches" in general were scarce, how- up; 17 appeared in the Mountain West Region ever. Lark Buntings were especially abundant where over 150rare parulid records were logged through the Southwest. Frequently overshadowingall other specieswas the Black-throated Blue, which "irrupted" in the LONGITUDINAL DISPLACEMENTS Mountain West and elsewhere. It was reported Western birds in the East -- Eared Grebes from 12 localities in the Southern Great Plains again reached eastern Lake Erie. Also notewor- (where normally "extremely rare"); there were thy were a White Pelican in Vermont, Black seven Southwest sightings, 19 near Denver, 23 Brant at New York City, Ross' Geese in many from Nevada, and the total of 30 in southern places east to Quebec, and a good scattering of California was eclipsed only by 38 Palms, 57 tree ducks. Franklin's Gulls appearedin Quebec Tennessees, and 69 Blackpolls. and New York. There were extraordinary reports Six Connecticut Warblers in California make of Sharp-tailed Sandpipersin Iowa and Illinois. one reported from Arizona seemless unlikely, it Rufous Hummingbirds were expected in the Cen- would be new for that state. Arizona did get its tral Southern Region but the one in Minnesota first Canada Warbler this fall, Nevada its first was not. Apparently fewer than 20 western pas- Palm. New for Washingtonwere the Cape May serines travelled east. Only three warblers were and Magnolia. British Columbia had its first among them: a Townsend's in Wisconsin and Chestnut-sided. The Northern Pacific Coast Re- singleBlack-throated Grays in Pennsylvaniaand gion also hosted Black-and-white, Tennessee, Florida. Blackpoll and Palm Warblers -- all real rarities Eastern birds in the West --Displacement there. The Golden-winged was new to Ok- once again favored western birders with many lahoma. Dozens of second, third and fourth state species, at least 46 of them passerine. Two records resulted from the incursion. There was Black-billed Cuckoos in western Texas closely not merely one grand movement; the birds kept followed one which provided a new state record coming. For example, Chestnut-sided Warblers and first regional specimenin New Mexico. An already were in coastal California by Sept. 2, yet eastern Yellow-billed Cuckoo was captured on some struck an Oklahoma TV tower a month the Farallon Islands. Vireos scored well with later. Blackburnians were first seen on the coast White-eyed in Colorado, Red-eyed and Yellow- Sept. 5, a day later than one in New Mexico, throated each in three western states, and Phila- another struck a Dallas tower Sept. 15, and still delphia in California. The Brown Thrasher in others appeared in Nebraska and Oklahoma dur- Alaska was that state's first mimid. Northern ing October. Golden-wingeds were in southern

Volume 29, Number 1 27 California Sept. 14 but others hit the Oklahoma all had arrived somedays before they were found tower on Oct. 8. The invasion of the Pacific Coast we are left with no full explanation. Of the eastern began in mid-Augustand was still evident three warblers,some so prominent in the fall flight(e g months later. Black-throatedBlue) were rarely if at all rep- Stressedby all the Californiaeditors is the fact resented in the West last spring. Some southern that increasedobservation alone was not respon- species (Worm-eating, Prothonotary, Hooded, sible for the many 1974reports ofparulid rarities. Blue-winged)of 1974'sspring displacement were McCaskie indicates there were "not appreciably very rare or absent in the fall. There seemsto be more" observersin his regionthis fall; and more- little direct correlationbetween this year's spring over, it was the "old well-worked spots," not and autumn phenomena. (If it is true, however, new areas, that yielded the unusual birds. It was that less experienced immature birds are unable much the same in the Southwest and, I suspect, to reorient once displaced, such birds from this elsewhere. Clearly more birds were involved this fall's flight which survive the winter should be year. We're still left with more questions than expected to return to their breeding groundsvia answers, of course. Was weather repeatedly dis- the "wrong" route they first used. Western ob- placing large numbers of migrants over a three- serversshould be alert for this next spring.)The month period?Have westward drifters survived present situation may be the culmination of an- m sufficient numbersover the years to have pro- nual westward drift over a period of years, fol- duced progeny now retracing in force their mod- lowed by the gradualestablishment of new routes Ired migratory pathways? Did some of last and possibly some new breeding areas. (Re- spring'sstrays remain in the West to breed, thus memberthe Parulaswhich nestedin Californiag) swelling numbers this fall? Are intrinsic or ex- Perhapswe're now witnessingon a grand scale trmsic factors interfering with navigationalabil- the same sort of thing we have seenbefore in one ity of ever-increasingnumbers of eastern(but of species at a time. In 1957 there were but three fewer western) birds? Or were there just many New Mexican records of Indigo Buntings.Since more warblers produced this year in the usual then the specieshas become rather widespread breeding areas, thus impressively augumenting here, not only as a migrant but nestingregularly the now usual west-southwest drift of many tra- even in the southwest portion. It now seems ditionally eastern species? firmly entrenched.Colorado's Blue Jaysprovide Answers seldom are obvious and space pre- another example. cludesmuch discussion. However, I would agree Looking eastward for some clue we find no with Stallcupet al. that much of the explanation uniform lack of warblers there. Douglas Kibbe lies in wind conditionsresulting from high pres- writes of good flights through the Western New sure systemsover Canada early in August, about York-Western Pennsylvania Region. George the time many species begin their southbound Hall's illuminating report reveals poor or normal flight. The resultantNE winds must have started migrationin placesbut "unusually heavy" war- numbers of birds drifting off courseto the South- bler movement in Ohio, West Virginia, and east. Then, in late August-early September, a northern Georgia. So despite poor showingsm second high over the northwestern part of the some spots, it seemsthat great numbersof the continent likely continued the displacement. very specieswhich moved west also passed along Again, prevailing NE winds from mid- to late traditional migration paths. With only eastern Septemberacross the northernplains, the Rock- data at hand nothing would appear odd. Enor- les and the Great Basin obviously favored south- mous numbers of young must, therefore, have western movement.Finally, there followed a pe- been raised this year on these warbler's boreal riod of weak fronts, often with E and S winds, breedinggrounds. One wondersjust what condi- into early November. We had many days of E tions prevailed in the northern and northeastern windsacross southern New Mexicoas well, andI forests last summer, for most of this fall's west- cannot avoid the obvious association of 1974's bound warblers nest in that zone; so do eight of autumnalair movementsand the appearanceof the speciesdiscussed above under"irruptions" eastern birds. As the winds favored the latter, Whatever the causes, several years' longitudinal they operated against western species which displacements of increasing magnitude show often wander east. As noted above, remarkably beyond doubt that the western status of some few landbirds moved in that direction. "eastern" warblers has changedmarkedly. No But did the wind account for it all? As McCas- longer can some of these -- like the Blackpoll m kle says, "What weather factor or factors could California- simply be termed vagrants.They bring Tropical Kingbird, Red-throated Pipit, have passedthat point. What we shallhave to call Sprague'sPipit and Black-throated Blue Warbler them a few years hence is one of the mostintrigu- all to one spoton the sameday?" Even assuming ing questionsof all.

28 AmericanBirds, February, 1975