The followingarticle is the firstin a serieson Californiararities to be edited by JosephMorlan and Don Roberson.It is basedon materialssubmitted to the CaliforniaBird RecordsCommittee (CBRC). The descriptionand cir- cumstanceswere drawnfrom the accountsof the observersand have been reviewedby them. Robersonprepared the distributionalsummary; Morlan preparedthe identificationsummary. In thisway we hope muchimportant informationaccumulated in CBRC files will becomewidely available.

Wedge-tailed Sketch by Tim Manoils

FIRST RECORD OF THE WEDGE-TAILED SHEARWATER IN CALIFORNIA

RICHARD STALLCUP, Box 36, Inverness, California 94937 JOSEPH MORLAN, 417 Talbot Ave., Albany, California94706 DON ROBERSON, 282 Grove Acre Ave., Pacific Grove, California 93950.

On 31 August1986, Stallcupwas leadinga pelagictrip for the PointReyes Observatory.At about 0900, he was standingat the stern of the Sea Wolf about 4 nauticalmiles due westof Point Pinos,Monterey County, when an unusualshearwater glided by, headingtoward a largeflock of gullsand shearwatersin the boat's wake. The bird was very close and it took him a secondto realize that it was not any expectedspecies. He shouted "What is that? What is that bird? Get onto that bird!" The shearwater melted into the flock but quicklyreappeared about 40 feet behind the boat. Its unique shape, dark bill, pink feet, and nearly uniformdark brown upperpartssug- gesteda Wedge-tailedShearwater pacificus, a speciesStallcup had seen off western Mexico and southeastern Australia. All 20 other observersclustered at the stern, many strugglingto see details as Stallcupyelled out "What'sthe preciseunderwing pattern? Is the bill all dark? Who has a camera?' Then he remembered his own camera and was soon photographingthe shearwater,guessing at the proper exposure,until he ran out of film. He obtained 17 photos (includingFigures 1-3); Alan K. Thomas obtained one more (Figure 4). Fortunately the bird was very cooperative,staying in the wake for an estimated10-12 minutes.It wasoften the birdclosest (30-50 feet) to the shipbut sometimesdrifted back or landed Western 19:61-68. 1988 61 WEDGE-TAILED SHEARWATER on the water. It flew outsidethe flock, up one sideor the other, crisscrossing and quarteringand droppingon tidbitsof chum. The quarteringmaneuvers provided excellent views of the spread tail and often of the dangling legs and feet. Stallcupobtained LORAN readingsfrom the captain (placingthe bird at 36 ø 38 • 16 iN, 122 ø 04 • 27 W) and radioedanother boat of birdwatchersabout 35 miles west. This secondgroup of observersscoured the area later that day, as did another charteredboat the following day, but the bird was not relocated. Stallcuptook the followingdescription, compiled from fieldnotes and with referenceto the photographs: A shearwatermost like Buller'sP. bulleriin sizeand shape but with a tail half again as long, muchwider, and more flamboyant.The wingsappeared long and slimin most views,but were wide, especiallyfrom the wristinward (suggestinglong secondaries?). The body was slimmerthan that of the Pink-lootedShearwater P. creatopus,being more like Buller'sin proportions,including those of the head and bill. The flight was extremelygraceful, like Bullet's,with effortlessflapping broken by sustainedgliding on bowedwings. The flapswere smooth,unlike the more laboredflight of the Pink-looted, and this bird used the lift from the waves more efficiently.It usuallystayed lessthan 3 feet from the surface,but occasionallywheeled up to perhaps20 feet. When com- peting for chum it displayedthree notable behaviorialcharacteristics: (1) it blatantly used its large tail to outmaneuvereven the agile Heermann's Gulls Larus heerrnanni, quarteringwith its body to drop onto floatingfood items,reminding one of a harrier Circus, (2) it often foragedwith its legsand feet hangingdown, and (3) it sometimes pulled its head back a bit, giving an "Adam's apple" effect to its long neck. The entireupperparts were darkwithout noticeable markings. The remigesand retrices were black above and below. The crown, face, nape and a large peninsularsmudge projectingonto the side of the breastwere blackish,merging with little contrastinto the ebonybrown back and upperwingcoverts. The tipsof somecoverts (probably greater coverts)were paler (wornor pale-tipped?), forminga barelynoticeable tan stripenear the trailingedge of the upperwing. The chin, throat, breast,sides, belly, and flankswere pure white, but the demarca- tion from the dark upperpartswas rather fuzzy. The undertail coverts and lower flanks were dark. The underwingcoverts were mostlywhite, separatedfrom the whitebody by blackish axillars.The entiretrailing third of the underwing,made up of the remiges,was dark, as was a narrowstrip on the leadingedge, only slightlywider than that of Buller'sShear- water.A dark diagonalline, fromjust inside the wriston the leadingedge to the posterior axillaries,isolated a smalltriangle of white on the underwingcoverts, producing a field characterapparently unique to the light morph of this species. The bill appeareddark in the field, but was subtlyblack-tipped on the distalquarter and darkestblue-gray on the remainingbasal portion. Eyes appeareddark. Legs and feet were pink, recallingthose of Pink-looted Shearwater. At Stallcup'ssuggestion, Ruben Balzer, Bill Manolis,Nancy Menken, Susan Peaslee, Alan Thomas, William Ure, and Katherine Wilson submitted addi- tional descriptions.These were similar in most repects to Stallcup's, although Manolis describedthe back as "chocolatebrown" and the feet as "flesh-colored." The recordwas unanimously accepted by the CaliforniaBird RecordsCom- mittee on the first circulation(Bevier in prep.). It constitutesthe first record for California and for North America north of Mexico.

62 WEDGE-TAILED SHEARWATER

Figure1. Wedge-tailedShearwater. Monterey Bay. 31 August1986. Note outlineof white triangleon underwingcoverts and long wedge-shapedtail. Photo by Richard Stallcup

Figure2 Wedge-tailedShearwater. Monterey Bay, 31 August1986. Note narrowpale tips to greater coverts forming a narrow wing stripe Photo by Richard Stallcup

63 WEDGE-TAILED SHEARWATER

Figure3. Wedge-tailedShearwater, Monterey Bay, 31 August1986. lXlotethe long, thingray bill with slightly darker tip and black flight feathers contrasting with white wing linings. Photo by Richard Stallcup

Figure4 Wedge-tailedShearwater, Monterey Bay, 31 August1986. The head is pulled back.producing an "Adam'sapple" effect, and the longsecondaries give a distinctive broad-based appearance to the wings. Photo by Alan K. Thomas

64 WEDGE-TAILED SHEARWATER

DISTRIBUTIONAL SUMMARY

The Wedge-tailedShearwater ranges widely throughout the tropicalPacific and Indian oceans.It occursin the easternPacific from Baja California(A.O.U. 1983) to Ecuadorand throughoutthe centraland westernPacific, north to Japan and southto southernAustralia and New Zealand. It occursin the In- dian Ocean from western Australia to southern Africa and north to the north- ern Red Sea (Jouaninand Mougin 1979, Sinclair1978, Shirihai 1987). All breedingcolonies are on tropical or subtropicalislands. Pacificpopulations of this polymorphicspecies consist predominately of the lightmorph in the north (exceptat the Marianasand Revillagigedos)and the dark morph in the south (exceptat SharksBay, westernAustralia, where 20-30% of the birds are light; Blakers et al 1984), with 10ø N latitude representingan approximatedividing line (King1974). The breedingcolonies nearest California are on San Benedicto Island, in the Revillagigedogroup off southernMexico, and in the HawaiianIslands. The San Benedictobreeding populationwas two-thirds dark in 1898 but wasnearly all dark by 1974 (Jehl and Parkes 1982). However, sightingsat sea near the Central Americancoast (east of 120ø W) are predominatelyof the light morph, with dark birds becoming more numerous only far offshore (between 120 and 150 ø W; Pitman 1986). The Hawaiian populationis estimatedat 1.5 million birds (Haley 1984), and 97% of the birdsaround the main islandsare of the light morph (Berger 1981). They nestfrom Marchto November,then movesouth to the Equatorial Countercurrentand east to waters off Central America, completinga molt prior to returning to their breeding colonies (Berger 1981, King 1974). A vagrant from this long migrationroute might accountfor the bird reaching Monterey during fall, as most other populationsare nonmigratory (Jouanin and Mougin 1979) and mostsouthern populations are dark. Largeflocks usual- ly remain near the Hawaiian breedinggrounds until November, so this bird may have been a nonbreeder. The bird wasnot associatedwith any stormor sea-temperaturefluctuation (e.g., "El Nifio"). Seasin the vicinitywere calmwith a three-footground swell; the weather was calm and overcast.King (1974) found the Wedge-tailed Shearwater insensitiveto water temperature, as long as the temperature was above21 ø C (70ø F), and foundit only slightlysensitive to salinity,preferring salinitiesabove 34.6 partsper thousand.However, he citedtwo recordsfrom watersof 15 ø C (59 ø F), showingthat the speciesis not entirelyrestricted to warm water. On 31 August1986 the surfacetemperature at HopkinsMarine Station,Pacific Grove, 8 mileseast inside Monterey Bay, wasonly 13.5 ø C (56.3 ø F) and temperaturesoff Point Pinosaverage even cooler (A. Baldridge pers. comm.). At Granite Canyon, about 15 milessouth of the sighting,the temperaturewas 11.7 o C (53.1 o F; ScrippsInstitute of Oceanography1987). Thus the water temperaturewhere the shearwaterwas seen was probably no higherthan 12 ø C. Sea temperaturesin the Monterey Bay region were 2-4 ø C warmerat the beginningof August(Scripps Institute of Oceanography 1987) but had cooledby the end of the month. The previous records nearest California were sightingsof both light and dark birds16 December1956 off northernBaja California,Mexico (Murphy

65 WEDGE-TAILED SHEARWATER

1958), lessthan a day'scruise south of San Diego. The speciesis more regular off Cape San Lucas at the southerntip of Baja at about 21-22 ø N (Pitman 1986, Loomis 1918), nearly500 nauticalmiles farther south. The northern- most previousrecords were of birdsat 35 ø 26 • N in the centralPacific (King 1974) and a typhoon-blowndark bird at about 37 ø N at Toyama, Japan (Ornithol.Soc. Japan 1974). Though the occurrenceoff Montereysurprised many, Stallcuphad previouslypredicted that the Wedge-tailedShearwater would reach California (Jehl 1980).

IDENTIFICATION SUMMARY

The Wedge-tailedShearwater is most like Buller'sShearwater in shape and actions;Jouanin and Mougin (1979) consideredthe two to constitutethe subgenusThyellodrorna, characterized by a long, graduatedtail (Stejneger 1888). Both often fly low with wings angled forward, using gracefulwing strokesor relaxedglides on bowedwings, quite unlike the energeticwingbeats and stiff wingsof Pink-lootedand Flesh-lootedP. carneipesshearwaters. In all plumagesthe very longpointed tail, appearingwedge-shaped when fanned, distinguishesthe Wedge-tailedfrom mostsimilar species. Although many field guides de-emphasizethis character, we believe it is criticalin establishinga claim for this speciesoutside its normal range. When a Wedge-tailed Shear- watersits on the water,its tail projects beyond its folded wings (Ridgely 1976). The broad basesto the wings also impart a distinctiveshape. In plumage, the light morph is similarto the Pink-looted Shearwater, as it lacksthe strikingback and head pattern of Buller'sShearwater. The under- parts are alsosimilar to the Pink-looted's,showing dark undertailcoverts and broad dark trailingedges to the wings, unlike Buller's.Light-morph Wedge- taileds are rather variable in the extent of dark on the axillaries and under- wingbut average whiter there than most Pink-footeds. Wedge-taileds have a dark diagonalline extendingfrom the axillarstoward the wrist, forming the outline of a white triangleon the underwingcoverts, though the pattern is lessobvious on somebirds. On all Pink-footedsthese coverts are heavilystreak- ed or motfledwith brown, resultingin a darkeroverall pattern and no triangle effect. The billof the Wedge-tailedis variably gray with a slightlydarker tip (Harrison 1983) or "reddish-flesh"(Alexander 1954) or pinkish (Ridgely 1976). We do not know how manybirds have reddish or pinkishbills, but of the thousands of Wedge-tailedShearwaters P. Unitt (pers. comm.) saw in the centraland easternPacific, none had a pink bill. Specimensexamined by Robersonat the American Museum of Natural History with originalbill color noted were variouslydesignated as slate, gray, blue-gray, and slate with pinkishtinge. Any individualwith a graybill is not a Pink-lootedor Flesh-lootedshearwater. The dark morph of Wedge-tailedShearwater could be confusedwith Flesh- looted, SootyP. griseus,Short-tailed P. tenuirostris,or ChristmasP. natiuitatis ,but the former'svery longpointed tail, angledwings, and buoyant flightshould be diagnosticin reasonableviews. Sooty and Short-tailedshear- waters are easily distinguishedby their much paler underwingsand very differentshape and flightcharacteristics. The ChristmasShearwater resembles a small dark Wedge-tailed Shearwaterbut has a shorttail and a slow, zig-zag

66 WEDGE-TAILED SHEARWATER flight (Meeth and Meeth 1979). Harrison (1983) claimedthat dark Wedge- tailedshave solidlydark underwingswhile Flesh-footedshave paler under- sidesto the primaries,but no such differenceis apparent in the photos pub- lishedby Harrison (1987) nor have we noted it in the field. In reality, dark Wedge-tailedsare highlyvariable. Birds of more southerlypopulations tend to be uniformlydark, while more northerlybirds usually have the entireunder- parts paler neutral gray (Murphy 1951, King 1967). For convenience,we callthe latterplumage the "graymorph." Gray birdsintergrade with lightbirds in the North Pacific,although typical birds greatly outnumber intermediates in collections(Jehl and Parkes 1982). Morlan's examination of specimens at the CaliforniaAcademy of Sciencessuggests that intermediatebirds may be categorizedinto two basictypes: a gray morph with a white throat and a light morph with a gray band acrossthe breast. Dark Wedge-tailedShearwaters are most likely to be confusedwith the smaller,poorly known Jouanin'sPetrel Bulweria fallax of the northernIndian Ocean. That species'range at sea is largelyunknown, althoughit has been collectedin Hawaii (Clapp 1971), and there is a specimenfrom Italy whose provenanceis disputed(van den Berg 1987). Apparently Jouanin'sPetrel was overlooked until first discovered in the Arabian Sea in 1955 because it was confusedwith Wedge-tailed Shearwater (Jouanin 1955, Gallagher and Woodcock1980). It closelyresembles dark Wedge-tailedShearwaters in col- oration and in its long pointed tail. It differsprimarily in its smallersize, much shorterand thickerbill, which in flightis held downwardat 45 ø (van den Berg 1987), and a faint pale area around the base of the bill (Harrison 1987). The feet of the Wedge-tailedShearwater are usuallypink, but the outer toe and web and the outsideof the tarsusare dark (Penny 1974). In the hand all Wedge-taileds, including unfeathered chicks, are said to be reliably distinguishedfrom all similarspecies by their white toe-nails (Slater 1970). This fine point is unlikelyto be of value in the field, but might help establish the identity of a decomposedcorpse should one wash ashore.

ACKNOWLEDGMENTS

We thank CBRC membersJon L. Dunn, Jeri M. Langham, and CurtisMarantz for their helpful commentsin reviewing this record, Stephen F. Bailey for assistancein examiningspecimens at the CaliforniaAcademy of Sciences,Mary LeCroy and the Frank F. Chapman Memorial Fund for assistancein examiningthe American Museum collection,and Alan Baldridgefor data on water temperaturesin Monterey Bay.

LITERATURE CITED

Alexander, W. 1954. Birds of the Ocean. Putnam, New York. American Ornithologists'Union. 1983. Check-Listof North American Birds. 6th ed. Am. Ornithol. Union, Washington, D.C. Berger, A. 1981. Hawaiian Birdlife. 2nd ed. Univ. of Hawaii Press, Honolulu. Bevier, L. In prep. Eleventhreport of the CaliforniaBird RecordsCommittee. Blakers,M., Davies,S., and Reilly, P. 1984. The Atlasof AustralianBirds. Melbourne Univ. Press, Carlton, Victoria. Clapp, R. B. 1971. A specimenof Jouanin'sPetrel from LisianskiIsland, northwestern Hawaiian Islands. Condor 73:490. 67 WEDGE-TAILED SHEARWATER

Gallagher, M., and Woodcock, M. 1980. The Birds of Oman. Quartet, London. Haley, D., ed. 1984. Seabirdsof the EasternNorth Pacificand Arctic Waters. Pacific Search Press, Seattle. Harrison, P. 1983. Seabirds:An IdentificationGuide. Houghton Mifflin, Boston. Harrison,P. 1987. A Field Guide to Seabirdsof the World. ChristopherHelm, London. Jehl, J. R., Jr. 1980. Trends in the state list of California birds. W. Birds 11:103-109. Jehl, J. R., Jr., and Parkes,K. C. 1982. The statusof the avifaunaof the Revillagigdo Islands, Mexico. Wilson Bull. 94:1-19. Jouanin,C. 1955. Une nouvelleesp•ce de .Oiseau Revue Fr. Ornithol. 25:155-161. Jouanin, C., and Mougin, J.-L. 1979. ,in Check-Listof Birdsof the World (E. Mayr and G. W. Cottrell,eds.), Vol. 1, pp. 48-121. Mus. Comp. Zool., Cambridge, MA. King, W. B. 1967. PreliminarySmithsonian Identification Manual: Seabirdsof the Tropical PacificOcean. U.S. Natl. Mus., Washington,D. C. King, W. B. 1974. Wedge-tailed Shearwater (Puffinuspacificus), in Pelagic studies of seabirdsin the centraland easternPacific (W. B. King, ed.), pp. 53-95. Smithso- nian Contr. Zool. 158. Loomis, L. 1918. A review of the albatrosses, and divingpetrels. Proc. Calif. Acad. Sci., Ser. 4, 2:1-187. Meeth, P., and Meeth, K., 1979. Seabird observationsfrom six PacificOcean cross- ings. Sea Swallow 30:58-65. Murphy, R. C. 1951. The populationsof the Wedge-tailed Shearwater (Puffinus pacificus).Am. Mus. Nov. 1512:1-21. Murphy, R. C. 1958. The vertebratesof "Scope" (November7-December 16, 1956). U.S. Dept. Interior Spec. Sci. Rep.--Fisheries 279:101-111. OrnithologicalSociety of Japan. 1974. Check-listof JapaneseBirds. 5th ed. Gakken, Tokyo. Penny, M. 1974. The Birdsof the Seychellesand the OutlyingIslands. Collins, London. Pitman, R. 1986. Atlas of Seabird Distributionand Relative Abundance in the Eastern TropicalPacific. Admin. Rep. LJ-86-02C, U.S. Natl. Mar. Fish.Serv., Southwest FisheriesCenter, La Jolla, CA. Ridgely,R. 1976. A Guideto the Birdsof Panama.Princeton Univ. Press,Princeton, Nj. ScrippsInstitute of Oceanography.1987. SurfaceWater Temperaturesat Shore Sta- tions, U.S. West Coast, 1986. SlO Ref. 87-11, Univ. of Calif., Scripps Inst. Oceanogr., La Jolla, CA. Shirihai,H. 1987. Shearwatersand othertubenoses at Eilat. DutchBirding 9:152-157. Sinclair,J. 1978. Sight recordsof the Wedge-tailedShearwater off southernAfrica. Ostrich 49:46. Slater, P. 1970. A Field Guide to Australian Birds. Vol 1, Non-passerines.Rigby, Adelaide. Stejneger,L. 1888. Furthercontributions to the Hawaiianavifauna. Proc. U.S. Natl. Mus. 11:93-103. van den Berg, A. B. 1987. Jouanin'sPetrel. Dutch Birding9:72-73. Accepted 28 May 1988

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