First Record of the White-Collared Swift in California
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The following articleis the fourth in a serieson Californiararities edited by Morlan and Roberson. It is based on materialssubmitted to the California Bird Records Committee (CBRC). The descriptionand circumstanceswere drawn •rom the accountsof the observerand have been reviewed by him. Robersonprepared the distributionalsummary; Morlan prepared the iden- tificationsummary. In this way we hope much important informationac- cumulated in CBRC files wiI] become widely available. White-collared Swift Sketch by Tim Manoils FIRST RECORD OF THE WHITE-COLLARED SWIFT IN CALIFORNIA RICHARD A. ERICKSON, P. O. Box 523, Bayside,California 95524 JOSEPH MORLAN, 417 Talbot Ave., Albany, California94706 DON ROBERSON, 282 Grove Acre Ave., Pacific Grove, California 93950 At midmorningon 21 May 1982, Ericksonand his birdingcompanions Lynn C. Berner, Gary S. Lester,Gary J. Strachan,and RichardS. Tryon were near the sprucegrove at PointSt. George,Del Norte County,extreme northwesternCalifornia, when a swiftcaught their attention.Erickson's first impressionwas of Black Swift Cypseloidesniger, but Strachannoted white on its neck; soonthe whole groupfocused on the bird. It was a largeswift with tatteredprimaries that fed with a flock of swallows,including Barn Hirundo rustica,Cliff H. pyrrhonota, Tree Tachycinetabicolor, and Violet- •reen T. thalassinaswallows, over the õrassyheadland northeastof the spruceõrove. The morninõfoõ wasbreakinõ up and liõhtinõconditions were õood.The observerswatched the birdwith binoculars and a 20 x telescope, as it approachedthem sometimesto within 15 m, for 20 to 40 minutes.The swiftfed from a heightof 100 m to within8 m of the ground.The following descriptionis paraphrasedfrom Erickson'sfield notes: A swiftof typicalshape (slimbody with extremelylong wingsand apparentlyno "wrists")with a tiny bill and a slightlyforked tail of moderatelength. It absolutely dwarfedevery swallowin association,even at great distances.It was substantially longerthan a Cliff Swallowseen in directcomparison. Gary Lesterfelt the wingspan wasdouble that of a Barn Swallow;I thoughtit was maybenot quitetwice as much. The plumage was entirelyblackish except for a conspicuouscomplete white collar, narrowestand cleanestacross the nape but broaderand lessdistinct and descending posteriorlysomewhat across .the breast. This collar, especially on the nape, wasvisible Western Birds 20:25-31, 1989 25 WHITE-COLLARED SWIFT at great distances.A specklingof whitishon the foreheadwas visibleonly at close range. The birdflew rather like other large swifts, with much gliding and occasionalbouts of rapid flapping.Once or twice the bird seemedto stall out and fold up for a con- siderabledrop in elevation.On at leastone occasion,the wingswere held arched belowthe level of the body as the bird flew parallelto the ground. Although the bird resembledWhite-collared Swifts $treptoprocnezonaris that Ericksonhad seen previouslyin Belize, the whitish specklingto the foreheadseemed anomalous, so the observersconsidered the possibilityof a partiallyalbino Black Swift. Ericksontelephoned Morlan, who then checked the nine specimensof $. zonaris at the Museum of Vertebrate Zoology, Universityof California,Berkeley. None had a whitishforehead, although a brief literaturesearch suggested that the Caribbeanrace might be so marked. Morlan noted that the White-collaredis a blackishspecies, whereas the Black Swift is decidedlysooty brown. Erickson next telephoned J. V. Reinsen, Jr., Curator of Birds at the Museum of Zoology, Louisiana State University (L.S.U.). Reinsen com- pared the verbaldescription to a collectionof about 60 $. zonaris,of which 43 were of the northern, mainlandrace mexicana.Twelve of thesehad scaly or mottled breastbands, evidentlya signof immaturity.This variationdid not appear to be related to sex or season. Adult females had narrower breast bandsthan had males.Many birdshad pale duskyfeathers on the forehead which, when viewed head-on, gave the forehead an almost whitish ap- pearance(less obvious from the side). Reinseneventually reviewed written descriptionsand concludedthat the bird was a White-collaredSwift, and becausethe collarwas lesswell marked on the breast,probably an immature of the subspeciesmexicana. Nine days after the sighting,Erickson and Lester visitedBurney Falls, ShastaCounty, to study Black Swifts,five of which they watchedat length and comparedto a nearbyVaux's Swift Chaeturavauxi. Of the BlackSwifts Erickson wrote Although these were clearly large swifts, they somehow didn't seem quite as massiveto me asthe Pt. St. Georgebird. More significant,though, was the brownish tingeto thesebirds, primarily on the throatand breast,and their manner of flight.The extremelyrapid, almost "twinkly" wingbeats of thesebirds were much more like those of a Vaux's Swiftthan I had recalled.In no way did I ever comparethe flightof the Pt. St. Georgebird to that of a Vaux'sSwift. The amountof tailforking and the extentof the whitishon the foreheadsof thesebirds varied from rounded and blackish,respec- tively, to forked and whitish,comparable to the Pt. St. Georgebird. This recordof the White-collaredSwift wasaccepted as a firstfor California by the CaliforniaBird RecordsCommittee by a 9-1 voteafter two circula- tions (Morlan 1985). The Committee reviewed descriptionsfrom all five observers,Erickson's sketch (Figure 1), and the analysisof J. V. Reinsen.All but one agreedthat the size,flight, blackishcolor, whitish-tingedforehead, and collarpattern (clean and narrowon the nape, broaderand morediffuse on the breast) ruled out an aberrant Black Swift. Obvious albinism is unknown in the Black Swift (Ross 1963, Gross 1965, C. T. Collins pers. comm.) but is known in other swifts,in which it usuallyinvolves only a few 26 WHITE-COLLARED SWIFT scatteredfeathers (Collins 1967, Catley 1978, Sharrock1978; see alsothe discussionof the White-chested Swift under "Identification" below). The lone dissenterobjected that the large size should have been more obvious,and noted how huge the White-napedSwift $. semicollarisof westernMexico ap- pears in the field. Other memberspointed out that the White-collaredis a speciesmuch smallerthat the White-napedand that the sizeestimates (about twicethe wingspanof the Barn Swallow)fit the White-collaredbetter than the Black Swift. The issueof the worn remigeswas discussedand the possibilityof an escapewas discounted.J. V. Remsen wrote (to L. C. Binford) that "we have at leastone specimenof half a dozenspecies with extremelyworn primaries (not shot damaged), including one White-collared from Peru. These in- dividualsare bedraggledenough that it would be apparentin the field." K. L. Garrett noted (in CBRC comments) similar tattered primaries on the Chimney Swift Chaeturapelagica in summerin southernCalifornia. In most swifts,the post-juvenalmolt in fall does not includethe remiges(Dickey and van Rossen 1938), and this accountsfor worn remigesnot being shed until the second autumn. •,i'•ck;Sl, e• cep• Co,,,pI e•-e wg;)e le•œ clear Figure 1. White-collaredSwift, Pt. St. George, 21 May 1982. Sketch by R. A. Erickson 27 WHITE-COLLARED SWIFT DISTRIBUTIONAL SUMMARY The White-collaredSwift ranges from north-centralMexico (Guerrero, San Luis Potosi, and Tamaulipas) south through Central America to north- western Argentina and southeasternBrazil and in the Greater Antilles (A.O.U. 1983; Figure 2). Little has been publishedabout its movements, although wanderingto Trinidad (especiallyJuly-October; Snow 1962, ffrench 1973) and the LesserAntilles (especially May-October; Bond 1979) has been noted. In the northwesternportion of its range, individualshave been seen in winter north to southernSinaloa (Morlan 1985, R. W. Stallcup pers. comm., B. E. Danielspers. comm.). There are four other records for the White-collared Swift in the United States: two reported on 4 December 1974 at Rockport, Aransas County, Texas (Webster 1975; currently under review by the Texas Bird Records Committee, G. W. Lasley pers. comm.); one found recently dead on 25 January1981, clingingto a screendoor on PerdidoKey, EscambiaCounty, Florida (4 miles east of Alabama, Hardy and Clench 1982, specimenat the Universityof Florida); a young male found dead on 8 March 1983, washed Figure2. Approximatebreeding range of the White-collaredSwift (shaded),locations of other North Americanrecords (asterisks), and this record (star). 28 WHITE-COLLARED SWIFT up on a beach on Padre Island, Kleberg County, Texas (Lasley 1984, specimenTexas A & M Univ.); and one seenflying north on 20 December 1987 near Freeport,Brazoria County, Texas (Lasleyand Sexton 1988, Ar- nold 1988; under review by the Texas Bird Records Committee). Both specimensappear to be 5. z. rnexicana(Hardy and Clench 1982, Lasley 1984). The Florida and Texas specimenswere linked to unusualweather or a favorablejet stream(Hardy and Clench 1982, Lasley 1984), but the Califor- nia record was not associatedwith any unusualconditions. The Sinaloa, Horida, and Texas recordsare for winter, when the speciesmay disperse from breedingcolonies. The Californiabird might have been a springmigra- tion "overshoot,"but recordsare insufficientto explain its occurrenceso far north. SUBSPECIES Peters (1940) recognizedfive subspeciesof the White-collaredSwift. Populations from Honduras to Peru, 5. z. albicincta, and those from southeastSouth America, 5. z. zonaris, have the "forehead sooty black, scarcelyif at all differentfrom the color of the crown." 5. z. rnexicanafrom Mexico to El Salvador and 5. z. pallidifronsfrom Cuba, Hispaniola, and Jamaicahave