changing seasons: low pressure

Fall Migration: August through November 1998

Franklin'sGulls made headlines from the Midwestto the SouthAtlantic Coast Region, as what mnsthave been many thousands weredisplaced eastward from their normalfall migratoryroute throngh the middleof the continent--alongwith scores of waterfowl speciesaad cranes. This Franklin's, though, was part of an earliermovement, itself above average if annual,eastward into the mid-Atlanticstates. The ChesapeakeBay and PotomacRiver hasin have hosted many more Franklin's than have surrounding regionsover the pastfew decades, with over 70 recordshere, but this first-winter bird was a first for well-watchedCalvert County, ,August 31, lggS. Photograph/MarshallJ. Iliff.

EDWARD S. BRINKLEY* In NovaScotia, a falloutof passerinesOctober 11 was, according to Blake Maybank'scorrespondents: "exhilarating. Exhausting. Perhapswe've been spoiled for good?"The falloutalmost defies veryteur autumnbird study. holdsOn some the localsuperlative level, eventthe exceptionalinthe history experience ofama- description." '•n incredibleconcentration of raritieson oneplace: maybe of a singleindividual bird that brightens the fall: consider the 34 speciesof warblerin onecounty in thesecond week of October-- emotionsthat must have accompanied the discovery of Illinois'sfirst hasthat everhappened anywhere else in North Americanorth of WhoopingCrane in 40 years,or a ProthonotaryWarbler huddled Mexico?"A month later, November10-12 and beyond,a fierce notfar froma Golden-wingedWarbler in NovaScotia in themid- cyclone(termed "an inland hurricane--Category 3"by editor Daryl dle of October.In fall 1998,each month waspunctuated, at some Tessen)swept across the Great Plains, into the GreatLakes, and east- spoton the continent,by a remarkableweather event, a displace- wardtoward the Atlantic. It movedmany thousands of waterfowl, mentof significantnumbers of birdsfrom their typical migration cranes,and, without recordedprecedent, massive numbers of routesor stopoversites. In severalcases, hurricanes and tropical Franklin'sGulls eastwardof typicalpassage and winteringareas. stormscaused the displacement,but in two other noteworthy Hurricanes'transportation of birds has been a staple of the instances,nontropical low-pressure systems transported a hodge- ChangingSeasons (Kaufman 1977, DeBenedictis1986, Lehman podgeof birdsinto areas where they are rarely seen, or rarelyseen in 1989,Brinkley 1997, Patten 1998), and strongfrontal passages and largenumbers. reverse-migrationevents also pepper past columns. But there were * 21238Huntington Road, Cape Charles, 23310 superlativesin 1998beyond past events.

NORTHAMERICAN BIRDS TheWhooping Crane and the warblers, those bright spots in the northwest and the southeastern U.S. coast. As its center neared the sportof birding,turn out to be partsof muchlarger patterns-- Carolina coast,the storm stalledjust off Wilmington, North patternsdetected and communicatedthrough networks of birders Carolina,on August25-26. The eyeof the stormmade landfall near acrossthe continent.With this communicationaccelerating at a Wilmingtonas a Category2 hurricaneearly on the 27th. While mov- dizzyingpace, and the stream of observationsshared over the inter- ing slowlyover eastern ,Bonnie weakened to a tropi- net alreadyoverwhelming even the mostassiduous archivists, the cal storm but restrengthenedinto a hurricaneas it movedinto numberof distinctlyweather-related bird reportsis too greatto Virginiawaters, where it passedoff to thenortheast and out to sea. digestin theChanging Seasons; and so, as in severalpast columns, Charleydeveloped from an areaof low pressurein thethe south- commentaryhere is limitedto the mostextreme events. In the cases easternGulf of Mexico.The systemformed into a depressionand of the tropicalcyclones, however, I havemade some attempt at strengthenedinto a tropicalstorm on August 21 about275 miles off broadersynopses, along with somecontextual notes on thedisplace- the southernTexas coast. Charley reached its peakintensity of 70 mentof certainspecies by suchstorms in thepast. The desirehere is mphbefore moving inland near Port Aransas the following day. After not simplyto refineunderstanding of weather'seffects for the pur- landfall,a slow-movingcirculation aloft persisted in the vicinityof poseof finding"vagrant" species (though this may be onebenefit) Del Rio, whereflooding rains devastated that areaAugust 23-24 but to continue efforts to understand how birds work with various Thoughrains were heavy on thecoast, Charley apparently lacked the weatherpatterns: which systems or conditionsare favorable for for- wind strengthto moveseabirds any distanceinland. Texas editors aging,migration, and nesting,and which are adverse--and,if Sexton,Lasley, Lockwood, Sekula, and Shackelford report that "the adverse,what specific behaviors of the birdsindicate to usthat they stormwas significant ornithologically for what'it didn'tproduce havebeen affected negatively? In thelarger view, it isnot too soonto therewas no majorpasserine fallout from the storm,and there were ask if our ownactivities have begun to showdrastic effects on glob- e•sentiallyhoinland pelagic strays?' Nevertheless, Charley did move al weatherpatterns, then how should our conservationstrategies for a goodnumber of MagnificentFrigatebirds on thecoast, and in inte- birdlifeanticipate the increasingweather-related losses they may rior areaslarge numbers of southboundBlack Terns and shorebirds lncur• (notablyBuff-breasted and Upland sandpipers) were "put down?' HurricaneEarl developedas a tropicalstorm over the southwest- AUGUST AND SEPTEMBER'S ern Gulf of Mexicoon August31, becominga hurricane150 miles HURRICANES AND TROPICAL STORMS south-southeastof New Orleans.After briefly attaining windforce of Septemberis traditionallythe most active month for Atlantichurri- 100 mph, the stormflirted with the Gulf Coastand madelandfall canes,and this past autumn Was not exceptional in thatregard, The nearPanama City, , on September3, becomingextratropical 14tropical cyclones this year, however, was once again a highnum- whilemoving northeastward through that day. ber-almost six abovethe averagesince 1886--and 10 of these Frances formed in the Gulf of Mexico 160 miles east of Browns- becamehurricanes. Seven tropical cyclones made landfall in the villeon September8, becominga tropicalstorm two days later in its UnitedStates, more than twice the annual average, with damageesti- moveto thenorth and northwest. The storm'swinds strengthened to mated at six and a half billion dollars. 65 mphas it movedashore north of CorpusChristi on September11. The 1998Atlantic season was also one of the deadliestin history Frances moved northward to the Texas/Oklahoma border where It and had the strongestOctober hurricane on record,Mitch, a dissipatedon September13. Thoughwashed-out roads and other Category5 storm.Tropical cyclones daimed an estimated11,629 hazardsprevented birders from assessingthe storm'scargo, "a storm hves in 1998, most of which were related to in wreckof epicproportion was apparent" nevertheless, with "oneof Central America: not since 1780 has an Atlantic hurricane caused so ßthe mostimpressive tallies of storm-blownstrays in manyyears;' as manydeaths. Of the 10 hurricanesin 1998,three were "major" hur- the Texaseditors describe it. MagnificentFrigatebirds and Sooty ricanes(Category 3, 4, or 5 on theSaffir-Simpson scale). This means Ternswere present in goodnumbers at manyTexas sites, and at least thatthe four-yearperiod of 1995-1998had a totalof 33 hurricanes, 14 Sabine'sGulls were recorded from interiorlakes, where other an all-timerecord for anyfour-year period. Predictions for 1999are waifsincluded Red Phalarope,Pomafine Jaeger, and an array of for moreabove-average activity, and, if increasesin hurricaneactivi- coastalterns. Undoubtedlya great many interestingpassefine ty areindeed linked conclusively to atmospheric carbon-dioxide lev- migrantrecords in mid-to lateSeptember are attributable to Frances els(e g.,Emanuel 1987), then long-term global models may be accu- as well. rate in predictingboth morefrequent and moreintense tropical Georgesformed in the far easternAtlantic from a tropicalwave on cyclonesin comingyears. September15, becominga tropicalstorm on the 16th.The storm The 35-dayperiod from August 19 to September23 waspositive- reachedhurricane-sfrength onthe 17thand in thenext several days ly furious:10 named tropical cyclones formed, and on September25, reachedapeak intensity of 155mph, a Category4 stormwith central four Atlantic hurricanes were on the move at one time--the first pressureof 937 mb attained on the 20th, 420 miles east of timesuch has been observed since 1893. Among the noteworthy bird Guadeloupe.Georges' landfalls were numerous: the first at Antiguain stormsin the yearwere Bonnie, Charley, Ear• Frances,Georges, and theLeeward Islands on the20th, the next over the U.S. VirginIslands M•tch.Tropical Storm Hermine crossed into southeasternLouisiana and on the 21st (winds 115 mph), thenceto the nearCocodrie September 20, with sustainedwinds of 40 mph,but it DominicanRepublic on the 22nd (winds120 mph).After crossing producedno knownavian fallout. the Hispaniolanmountains, Georges again made landfall in eastern Bonniedeveloped from a tropicalwave over the Atlantic 900 miles Cubaon the the 23rdwith windsof 75 rnph,continuing along the eastof the LeewardIslands on August19 and becamea tropical northerncoast of Cuba for most of the 24th. Early on the 25th, stormAugust 20. Late on the 21st, the storm strengthened into a hur- Georgesmoved into the FloridaStraits and reintensified,making ricane 200 miles north-northeastof Hispaniola. Bonnie then landfallnear Key West on the 25th(winds 105 mph). The stormcon- strengthenedto its maximum,with windsof 115 mph,late on the tinuedon a west-northwestto northwesttrack on subsequentdays, 23rd while 175 miles east of ,then turned toward the slowingdown as it drenchedcoastal portions of Alabama,

VOLUHE53 (1999), ISSUE1 13 Mississippi,and Louisiana September 27-28 andmade a finalland- and their near-regularappearances on the Carolinacoasts durmg fall nearBiloxi, Mississippi, on the 28th,with 105-mphwinds. The the warm monthssuggest that they sometimesmove northward on stormwas downgraded to a tropicaldepression bymid-morning on southwesterlies,outside the contextof tropicalcyclones (Brinkley, the 29th, 35 miles north-northeast of Mobile, Alabama. The remain- unpubl.;cf. Mlodinow 1999). On the other hand, as birds with lng weakcirculation center moved off the SouthCarolina coast on extremelylow wingloading,frigatebirds may be all the moresensi- October 1. tiveto displacementand may move (that is, flee) well ahead of the Hurricane Mitch formed in the southwestern centerof the low pressure(see Lehman 1989 on Gilbertof 1988).A froma tropicalwave 360 miles south of Kingston,Jamaica, on Magnificentat ChincoteagueN.W.R, Virginia, September20-27 October21, becominga hurricanethree dayslater. The storm thusmay have been an earlyrefugee from Georges,but the bird was reacheda minimumcentral pressure of 905mb (identicalto that of so far from the storm's center that such an association would be Camille of 1969) about 40 miles southeastof Swan Island on undemonstrable,in the absenceof a largerpattern, such as Gzlbert October26, the fourth lowest pressure measured in an Atlantic hur- showed.A paperon thedisplacement of frigatebirds into Florida's ricanein the twentiethcentury. Winds of 180mph madeMitch a interior,interestingly, finds that the averagenumber of frigatebirds strongCategory 5 hurricane.The Caribbeanisland of Guanajawas appearingaway from the coastdiffered little between major storms, first ravagedby the stormon the 27th;on the 29th,Mitch made minor storms,and moretypical weather (McNair, in ms.). landfallabout 70 mileseast of La Ceibawith 100-mphwinds. The Georgesmay have been responsible in part for the veryunusual storm moved southward over Honduras and Guatemala and weak- South Polar Skua action on the southeastern U.S. coast this fall One enedto a tropicalstorm on the lastdays of the month,producing on JekyllIsland, Georgia, stayed from at leastOctober 16 through veryheavy rains over portions of Honduras,Nicaragua, and neigh- November 5, and another, in Florida at Fort Clinch October 7-10, boringcountries, where the associatedfloods killed thousands of remained here after rehabilitation October 18-25. Later, after Mztch people.By November4, the centerhad reemerged over the Gulf of had moved offshore of southern Florida November 5, another South Mexicoand had again become a tropicalstorm, accelerating along a Polarfrequented Smyrna Dunes Park November 9-17. Inlandand frontalboundary in the easternGulf. Mitchmade a final landfall onshorePomafine Jaegers were widely reported in hurricane-swept nearNaples, Florida, on November5 (winds60 mph).By mid-after- areas,with at leastthree in Floridavery probably moved inland (fol- noon of the 5th the storm had moved offshore of southern Florida lowingEarl and Georges),and anotherat Fort Morgan,Lotuslana, andhad become extratropical. Both Mitch and Georgeswere respon- September12, after Frances.An unidentifiedjaeger, probably a siblefor a fewdisplaced birds on theNorth American continent, but Pomafine, was 20 miles inland in Mobile County, Alabama, their mostsignificant impact was on the islandsof the Caribbean September29, clearlythe issueof Georges.Gulls, other than the and,in the caseof Mitch,on the adjacentCentral American main- ubiquitousLaughing Gulls in the Southeast,are not oftennoted in land.Although several years will passbefore the effectsof these the contextof tropicalcyclones, and the unprecedentednumbers of stormsare understood,even for well-studiedenvironments such as Sabine'sGulls associatedwith TropicalStorm Frances(14+ Texas PuertoRico's mountains (see Robert Norton's West Indies column), reports)was reminiscent of someof 1996'sstorms (Brinkley et al oneshotfid not necessarilyassume the worstat thispoint. 1997).Elsewhere in the interior,however, record-high numbers of Amongthe waifs of hurricanes,truly pelagic seabirds are typical- Sabine'swere noted at widelyseparated locations; an increasein ly in the minority,and thisseems particularly true in yearssuch as observereffort or a productivebreeding season, or both, may be 1998, when Gulf Coast strikes outnumber those on the Atlantic contributingfactors to someof the Texascounts. ' seaboard.Other than in North Carolinaand Virginia, very few tube- Ternsare among the most conspicuous and widespread birds dis- noseswere noted in concertwith 1998'stropical cyclones. In the his- placedby hurricanes, and though the numbers of ternsdetected may toryof stormsthat affect the Gulf of Mexicorather than the Atlantic not be high,the varietyis oftenvery much so. Ten species of tern, coast,this is quite the norm and standsto reason,as the Gulf's plus BlackSkimmer, were found in the southeasternstates in the waters hold far fewer tubenoses than do the neritic waters of the contextof hurricanes,many of them deepinto the interior,where westernNorth Atlantic (see Peake 1996). Band-rumpedStorm- rare.Gull-billed Tern, typically an earlymigrant, is amongthe least Petrels,noted twice in Texasafter TropicalStorm Frances,are an commontern speciesnoted in tropicalcyclones, especially storms exceptionto the rule,as they appear to be relativelycommon in the that strike the northern half of the Atlantic seaboard. Hurricane deepwaterzones of theGulf of Mexico.Single Cory's and Audubon's Bonnieproduced one at SneadsFerry, North Carolina; Georges push- shearwatersand a MaskedBooby were found deadin Cameron ed anotherto Hattiesburg,a third for inlandMississippi. Another Parish,Louisiana, September 16, probablyalso done in by Frances. earlymigrant, Least Tern, was noted only early on, during Hurricane Observersin North Carolinareported moderately large numbers of Bonnie,at Goldsboro,North Carolina.Not quiteas early a migrant, deadCory's Shearwaters on barrierbeaches following Bonnie, but SandwichTern is nonethelessgenerally scarce as a storm-waifOne numbersof tidelinecorpses following hurricanes' passage are other- at LakeJackson, Florida, September 3, wasclearly the work of Earl, wise scarcein the literature,and large-scalemortality is virtually andtwo at GoldsboroAugust 27 were undoubtedly put thereby unknownin suchcases in the westernNorth Atlantic(an exception Bonnie.Royal Terns,probably the most numeroustern species is found in Auk 16: 247). detectedas a storm waif, were noted after Georgesin interior Earland Frances also both displacedmany Magnificent Frigate- AlabamaSeptember 30, after Bonniein interior North Carolina birds, particularlyinto the New Orleansarea, whereasGeorges August28 (with Forster'sTerns), and interiorFlorida after Earl It apparentlyput sevenfrigatebirds into interiorAlabama September shouldbe noted,though, that Royalshave a minorhistory of wan- 29-30, oneinto interiorMississippi October 7, andanother as far as deringwell into the continent'sinterior without apparentstorm- PulaskiCounty, Virginia, October 6. Frigatebirdshave a fascinating transportation;two 1998 recordsin Floridaand one at Callaway historyof stormdisplacement in theAtlantic and Gulf of Mexico. Gardens,Georgia, for instance,show no correlationwith the year's Many of the 90 or so easternrecords north of the Carolinassince tropicalcyclones. Georges may havebeen the forcethat brought 1880show little obviousassociation with particulartropical storms, Florida's coastal and inland Brown Noddies to Homestead and

14 NORTH AHERICAN BIRDS CHANGING SEASONS

BoyntonInlet, where rare, September 25-26. Inland Black Skimmers of entrainment in the storm is often difficult to surmise. Bonnie's werefound in Georgiatwice: September 11, after , and cargoin interiorNorth Carolinaincluded inland Black-necked Stilt, September30, after Georges. Another Georges skimmer on September Long-billedCurlew, Marbled and Hudsoniangodwits, and Red- 30 in Henry Countywas inland Alabama's fourth, and Floridahad neckedPhalarope. Texas editors also comments on the effectof threeEarl-birds September 3, onein LeonCounty and two at Lake Franceson migrantpasserines, surely an underinvestigatedphenom- Jackson. enon. Ternsthat normallymigrate across the continent'sinterior are Of particularinterest, too, are the behaviors of thevarious seabirds oftenwidely grounded by decaying tropical systems inland. About 45 displacedby suchstorms, in particulartheir flight behaviors during CaspianTerns at SamRayburn Reservoir, Texas, following Frances andfollowing entrainment. As for Berthaand otherstorms in 1996, September13, may well have been groundedinterior migrants. birdersactive after Bonnie and later tropical cyclones logged a wealth Bonmefelled four Black Terns at LakePhelps, North Carolina, and 60 of observationsof seabirds moving along with these intense systems. Blackswere at theOrangeburg Sod Farms, , following In North Carolina,for example,it wasapparent that tubenoses EarlSeptember 4. Of course,these birds may just as easily have been displacedinto the soundswest of-the barrierislands (the Outer displacedfrom the pelagic zones, where Black Terns are common at Banks)were sufficiently disoriented or weakenedby slow-moving this season. Bonniethat someshearwaters and storm-petrelswere still present a Trulypelagic terns, however, have no presencein the continent's weekafter the storm'spassage, when Tropical Storm Earls winds interioroutside the contextof storms.In North America,pelagic grazedthe .In mostcases, observations of tubenosesin the speciesare limited to Bridledand Sooty terns, and the latter has typ- soundswere made possible by windwardshorelines or bridges,espe- icallyoutnumbered the former by about9:1 in thehistory of storm- ciallybridges oriented roughly perpendicular to the wind direction. displacementof thesetwo speciessince 1869 (in 1996,about 15:2; in In hurricanesthat strike the Atlantic coast,the wind often shiftsfrom 1998,9:2). Preliminarycalculations of BridledTern's wingloading northeast(prior to passage)to southwest(after passage),so that andaspect ratio suggestthat Bridledhas a higherwingloading than bridgesor shorelinesrunning east-west appear to bemost productive. Sooty(32 asopposed to 24) andsimilar aspect ratio (10 versus9.9; In the caseof Bonnie,on August27, the Highway264 bridgeat calculationsmade per Pennycuick1989; Brinkley unpubL). This Manteo (which runs east-westover the CroatanSound) "corralled" relationshipfits well with comparisonsof otherspecies groups in a singleCory's Shearwater, two Black-cappedPetrels, a dark-morph otherfamilies of pelagicbirds, such as Procellariidae and Hydrobati- gadflypetrel (presumably a Herald [Trinidade]Petrel), two Band- dae within most groups,taxa with both relativelylower wing- rumpedStorm-Petrels, and one smallblack-and-white shearwater loadingand higher aspect ratio values tend to be thosethat show (Manx or Audubon's).The flight behaviorof all thesetubenoses greaterpropensity toward long-distance displacement. These trappedin theWaters on the south side of thebridge was identical: all numericalvalues, of course,relate to foragingand otherstrategies: flewUpwind and away from the bridge, in a southwesterlydirection, the highlypelagic aerialist such as SootyTern has lighterwing- into a south-southwestwind of 20-25 knots.Gradually, the wind loadingas a resultof evolutionfor coveringvast expanses of ocean movedthem northward, closer to thebridge ("backwards," inasmuch efficiently,for postnestingdispersal, foraging, colonization, and as their orientation was southwestward),and when within several otheraspects of itsnatural history. hundredmeters of thebridge, the birds became more active in flight, HurricaneBonnie produced a BridledTern at Goldsboro,North movingupwind more rapidly, often in poweredflight rather than Carolina,August 27, and four at theChesapeake Bay Bridge-Tunnel dynamic arcs, and then repeating the process, "slipping" slowly back- August28-29; Francesput Bridledsinto CameronParish, Louisiana wardtoward the bridge. (7 birds) and-Calaveras Lake, Texas (2 birds); and Georges- A weeklater, on September4, observersnoted that wind from the relatedBridleds were singles at FortWalton Beach, Okaloosa Coun- northwest,following Earl, concentrateda handful of Cory'sand ty, Florida,September 28-29 andHenry County,Alabama, Septem- Greatershearwaters on northside of theDaniels and Baum bridges, ber 30.A minimumof 16 SootyTerns was found during and after east-west structures that cross the Roanoke Sound east of Manteo. Francesin Texas,and "many"were seen and found deadafter the Thesebirds had dearly been deposited by Bonnie,as offshore charter samestorm in CameronParish. An immatureSeptember 16 at fishermenreported seeing numbers of storm-petrelsand shearwaters Shreveport,Louisiana, was farther-flung.In Florida,Earl downed in the soundsduring the week of August28 throughSeptember 3. SootyTerns at NewnansLake and Lake Jackson September 3, butsur- These shearwaters' behavior was similar to that of the birds in the prisinglyfew Sooties occurred on theheels of Georges;an immature CroatanSound, though they frequently alit on thewater, drifted clos- at Pensacola and adults at Fort Walton Beach and Homestead were erto the bridges, then flew upwind, away from the bridges (repea•ting theonly birds listed. In NorthCarolina, three Sooties were inland at the processlater). By contrast,the CurrituckSound bridge, a much JordanLake, and, in Virginia,17 were at the ChesapeakeBay Bridge- largerstructure, had concentratedonly a singleseabird, a Pomarine Tunnel,during Bonnie. Jaeger,on August27. Thisbridge runs north-south. Curiously, only Finally,in the rosterof ruffledfeathers, various long-legged one Bridledand three Sootyterns were seenin associationwith wadersand shorebirdswere found in unexpectedlocations, and Bonnie in interior North Carolina. someof these"potluck" records strongly suggest storm-transporta- After slowlycrossing eastern North Carolinaover the night of tion or grounding.An immatureGreater Flamingo at Fort Pierce August27, Bonniemoved off the coastof northeasternNorth Caro- September28 and an adultat St.George Island October 23-24 were lina and southeasternVirginia, where it restrengthenedto a hurri- thoughtto havebeen displaced by HurricanesGeorges and Mitch. A cane.After its passage just east of themouth of ChesapeakeBay, with recentarticle on hurricanedisplacement of flamingoes is muchrec- onshoregusts of up to 90 knots,observers at the ChesapeakeBay ommended (McNair and Gore 1998). Some of the Roseate Bridge-Tunnel(which runs north-southfor 17 miles acrossthe Spoonbillsnoted in augmentednumbers in centralTexas in Septem- mouthof ChesapeakeBay) on August28 notedsimilar flight behav- berwere believed to havebeen moved inland by Frances.Shorebirds ior in tubenosesand tropical terns. Rather few tubenoses were seen turn up in thestrangest places after tropical cyclones, and their point (as expectedwith hurricanesthat passto the eastof the coast)but

VOLlillE 53 (1999), ISSUE1 15 Figure2. A surfacemap showiug the tightly-packedisobars of the "GreatStorm," the low-pressurecell that movedthousands of cranes,geese, aud Frankliu'sGulls well eastof typicalpassage corridors(here November 10). NatioualClimactic Data Ceuter, Ashoville,North Carolina.

THE OCTOBER FALLOUT IN NOVA SCOTIA What BruceMactavish calls the "mostastonishing fallout of autumn passerinesever witnessed in the Region"occurred in the far south- westerncorner of Nova Scotiabeginning October 11. Three days before, a cold front had reached the Atlantic coast and stalled from Figure1. A surfacemap showiug isobars for the low-pressure CapeCod to northernFlorida. Forecasters often call such a systema area (hereoff the NewEuglaud coast, October 10) that drew "Carolinas front;' as influence is felt in areasto the north and the thoasaudsof migrautpesserines from southern climes, southof the mid-Atlanticareas. The front then pushed offshore over presumablyfrom arouud Florida, northward over the ocean the night of October9-10, and birdersup and down the eastern to southwesteruNova Scotia aud CapeCod. National Climactic seaboardantidpated good numbersof migrants,as are typically DataCeuter, Asheville, North Carolina. foundin coastalhotspots after a night of north and northwesterly winds.If the structureof thisfront was not particularlyuncommon, quitea fewdark-backed Sterna were in evidence.Of thosetubenoses itstiming and movement must surely have been (see McLaren 1981). seen--singlesof Cory's Shearwater,Black-capped Petrel, Band- Positionedin a shallowtrough, the counterclockwiseflow of a low- rumped Storm-Petrel,along with severalunidentified storm- pressurearea, its slow-movingcenter just off New Englandcoast petrels--allbut the Band-rumpedStorm-Petrel were flying into the (Figure1), ensuredthat northernand northwesterlywinds indeed 35- to 45-knotnorthwest wind (thusoriented roughly toward the prevailedalong the coastand offshorethat night, triggeringstrong bridge-tunnel),but in thiscase, moving off in a northeasterlydirec- migrationalong the entireseaboard. At its peripheryoffshore, how- tion. This cross-windmovement was most interesting in contextof ever,a strongsouthwesterly flow prevailed,so that birdsovershoot- the birds'physical orientation upwind: the birds were not, as in ingthe coastlineat night,or birdsbound for off-continentwintering NorthCarolina, hemmed in bythe bridge (they were not on itswind- grounds,found themselvesin unfavorablewinds. Such birds then wardside) but ratherwere slightly in the lee of the structure,orient- engagein "reversemigration;' moving downwind presumably in an ed a bit northof northwest,and so traveling gradually offshore with effort to savevaluable energy resources that would be quickly the wind,though deddedly not downwind.Of greatinterest, too, was exhaustedin attemptsto fly into a headwind. the observationthat 17 Sootyand four Bridledterns were mostly What musthave happened, according to Ian McLarenand Blake employingthe same sorts of locomotionas the tubenoses, the Sooties Maybank,is that thesereverse migrants, moving to the northeast in particular. over the Atlanticthrough the day on October 10, would have It will takemany more observations of this sortbefore specula- encountereddeteriorating conditions as they approached the center tion aboutthese behaviors can become hypotheses, but in lightof the of thelow that evening. With the prevailingeasterly and southeaster- recentwork by Larry Spearand David Ainley on seabirds'flight ly windsoff NovaScotia (and to a lesserextent ) of the fol- behaviors(see Spear and Ainley 1997a,1997b), particularly their lowingmorning, the survivingbirds would have made landfall at the observationthat tubenosesfor the mostpart tendto fly upwindmore firstpossible opportunity. On CapeSable Island, Shelburne County, routinelythan downwind,we maybe anotherstep closer to under- NovaScotia, the birdsbegan raining down on the islandat about3 standinghow and why certainseabirds "wreck" during tropical CM.Here warblersand other migrantswere seen coming in off the cyclonesand what behaviors they show in copingwith this ocean on the heels of a southeastwind with rain, at about the same displacement. time. Bird banderson Bon PortageIsland and SealIsland saw the

16 NORTH AMERICAN BIRDS CHANGING SEASONS samephenomenon, in miniature.One imagines with difficultythe adrenaline-soakedastonish- ment of localbirders tallying totals such as 700 Indigo Buntings,120 BlueGrosbeaks, a Black- billed and 14 Yellow-billed cuckoos, 95 White- ONTARIO eyed,20 Blue-headed,32 Yellow-throated,four Warbling,six Philadelphia,and 925 Red-eyed ---•-MICHIGAN 200+ L Mkh•anshore. vireos,one Western,eight Summer,and 100 Scarlet tanagers,or the hordes of warblers ILLINOIS (almost3000 warblersof 34 species).Most of the birdswere gone within a week. McLarenand Maybankattempted to corre- late estimated relative abundances of the migrantsseen in Nova Scotiawith long-term recordsof towerkills of nocturnalmigrants in northwesternFlorida (where, it seemsplausible, the bulkof NovaScotia's fallout may have origi- nated).They found that someproportions of birdsin Nova Scotiawere roughly suggestive of 15• Nov.14 a Floridaorigin, especially the eight most abun- • • V•RGINIA dant spedes:Red-eyed Vireo, Northern Parula, •BA• 2 Huntir• Creek. •.• FairfaxCo• Nov.14 Black-and-white Warbler, American Redstart, • C•esapeakeea• Common Yellowthroat,Scarlet Tanager, Blue • B•lg•TunnelI• J6 Grosbeak,and Indigo Bunting--all species \ I NORTHHooper Lane,CAROLINA largely absentfrom easternNorth America Henderson C•x Nov. 2S GEORGIA 4 SOUTHCAROLINA I F're Eight Island, north of Florida at this time of year and all 2 •Vest Point I Sa•annahS•x•lS•teNov.16 •x•HanoverC• Nov.27 Lake Dam Nov. 10 Lake Robinson Nov. 25 specieswith high or highestmortalities in the tower-kill data from the first third of October. Figure3. Recordsand reportsof Franklin'sGulls following the "reat Storm" Statisticallyspeaking, though, some of these of Novemherg-11, 1gg8. Thegreatest fnllout of gullswas detected between more abundantspedes in Nova Scotiawere pre- the Uppernnd Lower Great Lakes, south nnd southwest of LakeHichigan, sent in numbersmuch higher than the data andon the coastof NewJersey. from Floridawould havepredicted (American Redstart, Common Yellowthroat, Scarlet Tanager,Blue Grosbeak, and Indigo Bunting)and likewisethe pro- THE "GREAT STORM" OF NOVEMBER portionsof otherless numerous species were either too high (Hermit Thoughat leastone frontalpassage October 3-5 movedenormous Thrush, Black-throatedBlue and Black-throatedGreen warblers) or numbersof SnowGeese well east of theirusual passages (with at least too low (Gray Catbird,Palm Warbler,House, Marsh, and Sedge 10,000birds in New Brunswick),it was the "Great Storm"of Novem- wrens, Brown Thrasher, Wood, Gray-cheeked/Bicknell'sand ber 9-11 thatwas responsible for enormousdisplacements of geese, Swainson'sthrushes, Nashville Warbler) to fit the data from Florida's cranes,gulls, and other late migrantsfrom the Great Lakesto the tower-killsprecisely. Adjusting the statisticswith variablessuch as mid-Atlanticbeaches and beyond. With windsof 50 to 70 mph,(and medianwing-span and migrationdistance (possible indices of har- gustsof 90 to 100 mph) and the lowestbarometric pressure on dinessfor migrationover open ocean) apparently did not affectthese recordfor the Midwest,this stormwas one of the strongestof the discrepancies. twentiethcentury for themidcontinent--in a corridorthat regularly McLarenputs the question:"Are wrens,thrushes, and mimids seespowerful low-pressure systems (Figure 2). Aftermoving across low-altitudemigrants, particularly loathe to fly overwater?" Certain- the GreatPlains, the systemmoved northeastward over Lake Superi- ly, the altitudeof migratoryflight and the readinessto fly overwater or,and the states from Iowato Indianahad screaming westerlies that would be possiblevariables that could explainthe discrepandes shiftednorthwest, while on LakeMichigan, southerly winds gradual- betweentower-kills (which probably over-represent proportions of ly shiftedto the west.Veteran observer Dinsmore noted that the low-altitudemigrants) and the fallout's birds. The degreeof difficul- storm"produced one of the greatestmass migrations of waterfowl ty in detectionof less(or more) conspicuousspedes in certainter- and arguablythe largestmigration of SandhillCranes recorded in rainscan also prove derisive when comparing data sets such as these. Iowa thiscentury." Thepossibility exists, too, that migrants from many different sites on The Franklin'sGull flightwas without precedent for moststates the southeasternU.S. coast(not just Florida)were caught up and and provincesthat recordedits progress(Figure 3). By the second entrainedby the low. The behaviors of terrestrialspecies that become weekof October,large flocks (counts up to 60,000)had been staging entrainedin stormsover the oceanmake for instructivecomparison in Iowa, the raw materialfor the displacementthat would occura to thoseof pelagicseabirds displaced into equallydangerous terres- monthlater in statesand provinces east of theMississippi River. The trial envirouments:in both cases,the birds'efforts appear to be to greatestnumbers were found along a southwest/northeastaxis from minimizethe energy expended in entrainment(if notalways the dis- Illinoisand Wisconsin through Michigan to Ontario,in otherwords, tancetravelled during entrainment) and to minimizethe time spent to the southof LakesSuperior, Huron, and Michigan(and for the in the hostileenvironment. As onewould expect, flight behaviors to mostpart northof, or alongthe northernshores of, LakesErie and achievethese goals appear to varywidely among groups of birds. Ontario). In Michiganand Wisconsin,probably more than 3000

VOLUME53 (1999),1SSUE I 17 AUTUMN RECORDS OF FRANKLIN'S GULL andhow the entrainedbirds would have ended up hereis not imme- IN ONTARIO diatelyobvious. FOLLOWING THE "GREAT STORM" Not surprisingly,some birds lingered into Dekember at thesouth- NUMBER LOCATION I DATES ernextremes of themovement (at CapeMay andnear Cape Charles), I Kingsville [ November11 but small numberspersisted into Decembereven in Ontario (last 1-63 PointPelee I November11-19 birdsbeing singles on December1 in north-centralElgin County 1 Cobourg November11•14 and December5 at TurkeyPoint) and Michiganand Wisconsin 4 Presqui'le November11 Florida saw above-averagenumbers of Franklin'sGulls in late 1-27 Kettle Point November 11-12 s. shoreLake Ontario, November,involving some 14 birds in thelast ten days of themonth, 10 n. shore of Lake Erie, November 11-12 andsome of thesewere surely part of the eastwarddisplacement NiagaraFrontier Small numbersof Black-leggedKittiwakes and Sabine'sGulls 1 Pickering November12 were alsonoted in the context of this storm, but craneswere far more 4 [ HumberBay November12 3 LongPoint I November12 conspicuous,at least in theMidwest. Counts of SandhillCranes went 1 Oshawa November 13 throughthe roof, with between2000 and 7000 birds moving south in 5 Owen Sound November 14 Wisconsin,about 540 at HitchcockWildlife ManagementArea in 3 Wolfe Island November 14 Iowa,and 100 in ClayCounty, Missouri. Whooping Cranes were seen 1-10 FanshaweReservoir, London . November 13-21 twicein Iowaand once in Illin•ois,all on November11, with a single 19 PitrockReservoir, Woodstock November 18 flyoverat IllinoisBeach State Park providing the Illinois'sfirst firm 10 Wiarton November 18-19 recordsince 1958. On thesame day, Iowa hunters saw a flockof seven 6 LaurelCreek Reservoir, Waterloo November 19 to eight birds in BrennerCounty, and a singlebird cameto rest 18•2 n. centralElgin County, November19-25 se.Middlesex County amongSnow Goose decoys in PolkCounty! 2 PortPerry (inland) November19 Greater White-fronted Geese set records in the Southern Atlantic 30+ Rondeau November 19+ Coastregion (where editor Ricky Davis noted "a majoreasterly shift 6-10 Oliphant(Lake Huron) November19-20 in their migration"),as well as in Pennsylvania,Appalachian and 2 VanWagner'sBeach (Lake Ontario) November19 interior Ohio, the Indianalakeshore, western Florida, Mississippi, 5 Toronto November 19 2 PortTyerse (Lake Erie) November19 and Alabama.Snow Geese, along with small numbersof Ross's 3 Kincardine(Lake Huron) November19 Geese,were alsonoted in greaternumbers in often untradltlonal 3 TavistockSewage Ponds November19 locationsfollowing the Great Storm; to •vhat degree these augment- 2 MinesingFlood Plalm November20+ ed numbersreflect population increases in thiscase is unknown,but 4 PortStandley/Lake Erie November20+ November11-13 sawgreat Snow Goose flights in thesix states of the 6 fieldsn. ofIngersoll November20+ MiddlewesternPrairie region and in Louisianaand western Florida 4 __ _ WildwoodReservoir, St.Marys November20+ Followingthe Storm,a'strong count of 2300Ross's Geese was made weredetected, largely along the shoresof LakeMichigan, but large in ColoradoCounty, Texas, and "unprecedented" numbers of Ross's flockscould be foundinland for severaldays after the storm'spas- were found in Qudbec(a flock of seven)and in all the statesof the sage.As many as several thousand were also found in interiorIllinois, MiddlewesternPrairie region.Perhaps connected to the weather and477 passedMiller Beach,Indiana, in onlyan hourand a half on event,Wisconsin and Michigan both recorded "unusually large num- November12! As the windsdied down,there was apparently some bers"of Richardson'sCanada Goose (hutchinsii).Many locations movementof birdsinto southernIndiana, according to editorKen acrossthe borderstates and provinces reported very high counts of Brock. To the northeast, in Ontario, where well over 300 birds were TundraSwan during and after the Storm.A Wisconsingroup of 8000 recorded,the greatestconcentrations were apparently in Middlesex, to 10,000along the MississippiRiver south of LaCrossewas impres- Elgin,and Oxford counties. siveand equally so flocks of 10and 14in Qudbec,14 in Vermont,and Wherethe birdswent followingtheir eastSyarddisplacement is 16 and 28 in centraland southernMassachusetts. Few editors, per- difficultto discover.Some birds surelymoved south, as notedin hapssurprisingly, mentioned large concentrations of ducks displaced downstateIndiana, and recordssuch as those of 10 Franklin'sGulls eastwardby the storm.An Oldsquawconcentration at PointBeach, at Lake Robinson,South Carolina (northwestof Hartsville), Novem- Iowa,of some30,000 to 40,000birds was most definitely scattered by ber 25 suggestthat largenumbers may havepassed undetected in the Storm,but to whatparts is unknown. reservoirseast of theBlue Ridge and Appalachian Mountains. Editors Paxton,Burgiel, and Cutler track the movementof smallnumbers WHITHER LA NlrA? alongthe DelawareRiver and Lake Ontarioshoreline (where the E1Nifio/SouthernOscillation (ENSO) has received much attentionm sightof fouradult Franklin's Gulls at IrondequoitBay was extraordi- recentChanging Seasons columns (Price 1997, Patten 1998), partic- nary)and truly astonishing numbers along the Atlantic coast of New ularlyfor therecent powerful E1Nifio event, which began in themid- Jersey,where the Avalonseawatch noted at least42 birdsNovember dle of 1997(Kaufman 1997, 1998) and had begunto abateby the 14-15, with similarnumbers estimated at nearbyCape May on the springof 1998(Wamer 1998). By autumn 1998 the phenomenon had 14th (whereonly a dozensingle Franklin's had everbeen recorded givenway derisively to a so-calledLa Nifia event,in whichcolder- previously!).The concentrationof birdson theJersey shore may not than-normalwaters move into theareas previously warmed. In sharp simplybe an artifactof greaterobserver effort (as at theseawatch, or contrastto 1997, La Nifia's associatedweather patterns in 1998 at CapeMay Point):observers in New Englandand coastal Virginia encouraged,or at leastdid not hinder,the formationof strongtrop- had beenalerted to the phenomenonover the internetand made icalcyclones in the southernNorth Atlanticand Gulf of Mexico daily,diligent efforts to find Franklin'sGulls, for the mostpart with- Other than this relationship,though, it is difficultto saywhat out success.'s position to thesoutheast of thestorm may effectsLa Nifia has had in thepast year: perhaps because cooler waters havebeen ideal for the concentrationsof gullshere--though why are a bit closerto the "norm" on the North American west coast,the

18 NORTH AMERICAN BIRDS CHANGING SEASONS effectsof La Nifia on birdlifeare especially difficult to countenancein --. 1998.The changingseasons: Winter season, December 1, 1997- this informal forum. Certainly,the seasonlacked the incursionof February28, 1998.Field Notes 52: 158-159. largenumbers of commonerwarm-water seabird species well north Lehman,R E. 1989.The changingseasons. American Birds 43: 50-54. McLaren,I. A. 1981.The incidenceof vagrantlandbirds on NovaScotian of typicalrange (or lingeringthere late into the season):species such islands. Auk 98: 243-257. as Brown Pelican and Heermann's Gulls, for instance, did not make McNair,D. B. in ms.Assessment of inland occurrences of Magnificent headlines.The heavyrains of the previousfall werefor the mostpart Frigatebirdsin Florida:the influenceof storms.forthcoming, Florida absent,and thus Guy McCaskie writes in the SouthernPacific Region Field Naturalist. thatmigrants were able to passthrough southern California without McNair,D. B.,and J. A. Gore.1998. Assessment of occurrences of flamingos in northwestFlorida, including a recentrecord of the GreaterFlamingo beinggrounded. On the otherhand, eastern-central California did (Phoenicopterusruber). Florida Field Naturalist 26: 40-43. haveat leastone major low-pressuresystem in late Septemberand Mlodinow,S. G. 1998.The MagnificentFrigatebird in westernNorth earlyOctober that appearedto movemigrants strongly toward the America. Field Notes 52: 413-419. Patten,M. A. 1998.The changingseasons: Nora, E1Nifio, and strays from far coastand offshore islands, whereas Seattle (following a verydry early afield. Field Notes 52: 14-18. autumn)recorded its rainiest November ever. The autumnand early Peake,D. E. 1996.Bird Surveys.In: Distributionand Abundance of Cetaceans winterwere mild, andthe winterwould continue to be so,very much in theNorth-central and Western Gulf of Mexico: Final Report. Vol. 2: asin the previouswinter, whose warmth was, in mostmedia, tied to Technicalreport. OCS StudyMMS 96-0027.R. W. Davisand G. S. the presenceof a strongE1 Nifio. Fargion,eds. US Departmentof Interior,Minerals Management Service, New Orleans. In fact,despite the changeoverto La Nifia, regionaleditors in the Pennycuick,C. J. 1989.Bird Flight Performance: A Practical Calculation Middle PacificCoast and BritishColumbia write of the lingering Manual.Oxford University Press. Oxford. effectsof El Nifio,and editor Norton of theWest Indies region invites Price,J. 1997. The changingseasons: Spring migration, March 1-May 31, readersto considerthe effectsof E1Nifio for the tropicalAtlantic (see 1997. Field Notes 51: 832-835. that columnfor a relevantwebsite reference). Writing for centraland Spear,L. B. andD. G. Ainley.1997a. Flight behaviour of seabirdsin relation to winddirection and wing morphology. Ibis 139: 221-233. northernCalifornia, editors Roberson, Singer, Terrill, and Rotten- .. 1997b.Flight speed of seabirdsin relationto wind speedand direc- bornhypothesize that both "El Nifio/SouthernOscillation and more tion. Ibis 139: 234-251. long-termoceanic warming in theeastern Pacific may be at leastpar- Warner,N. 1998.The changing seasons: Spring migration, March l-May 31, tiallyresponsible for [the]rash of ultra-rarities"in California'socean 1998. Field Notes 52: 292-295. watersin recentyears (see the coverof this issue).They continue: "Overalloceanic food availabilitydecreases dramatically during warm-wateryears, resulting in birdsdispersing much morewidely than normal. Food may becomerelatively restricted to localized nearshorepatches, and wandering birds may find andfrequent these patches."Indeed, as several observers in Californiahave noted, it is notthe initial strong El Nifiowarming that produces the high counts of warm-waterpelagic birds off that statebut ratherthe subsequent year.Counts of LeastStorm-Petrel and Xantus'sand Craveris'mur- reletsappear to bearout thiscontention. The impactof the oscillationon bird populationsis difficultto assessin the absenceof comparabledata sets from pastdecades, as with all globalclimactic phenomena. As we awaitresults of long- termmonitoring projects, though, it will beprofitable to stayabreast of the big picture:to this end, DaphneGemmill of the National Oceanographicand AtmosphericAdministration has assembleda It •I•es moretitan k,cL to restorecritical wetlands bibliographyof papersin the biologicalsciences relevant to ENSO's potentialeffects on birdlife.Many of thesemake fascinating, dis- turbingreading.

ACKIIOWLEDGMEIVTS Manythanks to Ian McLaren(NS), Blake Maybank (NS), Brian Patteson (NC),Debra L. Shearwater(CA), and Douglas McNair (Ft) for sharingfield notes,commentary, and draft articleson specificweather events and phe- nomenaconsidered in thisseasonal summary.

LITERATURE CITED Brinkley,E. S. 1997.The changing seasons: The fall migration 1996. NationalAudubon Society Field Notes 5 I: 8-15. -,J. Lockyer, and T. Hass.1997. The Stormsof'96: Birdsand Atlantic It ta•:½syou. tropicalcyclones in an activeyear. Part I. FieldNotes 52:819-829. DeBenedictis,P. A, 1986.The changingseasons: A hurricanefall. American Birds 40: 75•82. P•t•tand r•to .... Emanuel,K. A. 1987.The dependence of hurricane intensity on dimate. Nature 326: 483-485. AMERICAN LAND Kaufman,K. 1977.The changingseasons: An intimatelook at Kathleenand CONSERVANCY

otheravian phenomena of 1976.American Birds 31: 142-152. Call us at 415.403.3850 -. 1997.The changingseasons: The nestingseason, June l-July 31, or visitus at www.alcnet.org -- learn how you can help. 1997. Field Notes 5 I: 960--963.

VOLUME53 (1999), ISSUEI 19