NOTES FIRST RECORD OF A CUCULUS CUCKOO ON MIDWAY ATOLL AND THE HAWAIIAN ISLANDS PETERPYLE, PointReyes Bird Observatory. 4990 ShorelineHwy., StinsonBeach, California 94970 JIM NESTLER. Department of BiologicalSciences. Walla Walla College. College Place,Washington 99324-1198 On 23 May 1997 we found and photographeda gray-plumagedcuckoo of the genusCuculus on Midway Atoll. constitutingthe first recordof this genusin the Hawaiian Islandsand in the centralPacific Ocean east of Palau.We suspectit was a CommonCuckoo of the southeasternsubspecies (C. canorustelephonus) but cannot eliminatethe Oriental Cuckoo (C. saturatus) at this time. Pylediscovered the cuckooat about1530 asit flewdown the activerunway toward FrigatePoint at the southwesterntip of the island.He alertedNestler by phone, then, in the companyof severalvolunteers assisting with seabirdresearch, pursued the bird aroundthe vicinityof FrigatePoint. We saw the bird both sittingand in flight and obtainedseveral photographs (Figure 1). The birdwas last seen at about 1630 flying Figure 1. Cuckoo(Cuculus sp.) on Midway Atoll, northwestHawaiian Islands, 23 May 1997. Photo by Peter Pyle 124 Western Birds 29-124-127, 1998 NOTES into a groveof ironwoods(Casuarina equisetifolia) to the southof the runway.We observedthe birdfor a total of 5 to 10 minutes,with 8x and 10x binoculars,at ranges as close as 20 m. Bothof usrecognized the birdas either a Commonor an Orientalcuckoo, and we concentratedon the underpartsand undertailcoverts of the bird, knowingthat this areawas important for identificationbut not knowinghow thesetwo similarspecies differedin the plumageof this region. We describedthe bird and Pyle sketchedit beforeconsulting any literature.The followingis a compositedescription based on theseoriginal field notes: A large cuckoo,larger than a Yellow-billedCuckoo (Coccyzusamericanus) and about the size of a female Sharp-shinnedHawk (A½cipiterstriatus) or, in direct comparison,a Brown Noddy (Anous stolidus).The upperparts,head, and breast wereuniformly medium-dark gray with a bluishtinge. The cuckoowas about the same color,if not a bit paler, than that of the upperpartsof an adultSharp-shinned or Cooper's (A½½ipitercooperil) hawk. The tail was blackishor black, contrasting distinctlywith the paler back and uppertailcoverts. When the bird wheeledin flight (beingchased by noddies),four or five partialwhite barsacross the tail were visible. The underpartsbelow the breastwere white, with indistinctgrayish barring. The grayishbars were approximately1 mm wide and did not contrastmarkedly with the white basecoloration. The exactpoint at whichthe barringstopped, ventrally, was not noted, but the undertailcoverts and vent area appearedto be white, without barring. The iris was yellow. The bill was blackishabove with a yellow base that extendedfarther along the mandiblethan alongthe maxilla. The literature(e.g., Cramp 1985, Redman1985, Parkes1990, Kennerleyand Leader 1991) indicates that the Common and Oriental cuckoos are difficult to separatein the field,the Orientalaveraging darker on the upperparts,which do not contrastmarkedly in colorwith the tail, and buffieror more ochreon the underparts, with thickerand blackerbarring, the ochre and barringextending to the undertail coverts.The subspeciesof the CommonCuckoo occurring in centralAsia and Japan, C. c. telephonus, has paler barring on the underpartsthan does the nominate subspeciesoccurring from Europe to Siberia(Cramp 1985, Parkes1990, Kennerley andLeader 1991). The OrientalCuckoo shows moderate geographic variation in size butlittle or no variationin plumage(Cramp 1985). To evaluatethe identificationof the Midwaybird, Pyleexamined all 24 specimensof the Commonand all 7 specimensof the OrientalCuckoo at the Museumof VertebrateZoology (MVZ), Berkeley,Califor- nia. This specimenexamination confirmed the variationnoted above(see Figure 2) and suggestedthat the Midway bird was a Common Cuckoo of the subspecies telephonus. The specimensof the Common Cuckooincluded 17 telephonusand 4 canorus. The specimensof telephonus(nine of whichwere collectedbetween 18 May and 7 June) had very indistinctbarring on the underpartsand, especially,the undertail covertsin comparisonwith nominateca norus and the OrientalCuckoo (four of which were collectedbetween 16 and 27 May);there wasno overlapamong the specimens in underpartplumage between telephonus and eitherof theseother forms (Figure 2). The birdof Midwayhad barringthat matchedthe palerspecimens of telephonus;in particular,a bird collected23 May 1953 near Seoul, South Korea (MVZ 130838; Figure 2), was nearly identicalin underpartplumage to that of the Midwaybird. Additionally,the Oriental Cuckoosall had bully or ochre-coloredbase coloration to the underpartsand undertailcoverts, in contrastto the pure white colorationof the Common Cuckoosand the Midway bird. These specimensimply that telephonus differsin underpartplumage more from nominatecanorus than the latterdoes from the Oriental Cuckoo,as noted by Parkes(1990). 125 NOTES Figure2. Specimensof Cuculuscanorus canorus (right two birds),C. c. telephonus (centertwo birds).and C. saturatus (left two birds).In each case the specimen(of thoseat MVZ: seetext) with the boldestbarring within each form is on the left. andthe specimenwith the sparsestbarring is on the right. The appearanceof the bird from Midway matchedthe paler specimenof telephonus(third specimenfrom the left). From left to right. MVZ 101637 (collected12 May), 109077 (2 July). 143575 (17 September).130838 (23 May), 134619 (19 May), and 140272 (16 May). The upperpartsof all CommonCuckoo specimens were similarin coloration,and differed from those of all specimensof the Oriental Cuckoo in being paler and contrastingmarkedly with the duskiertail. The upperpartsof the OrientalCuckoos were uniformly dark grayish to dusky, contrastingonly slightlywith the darker colorationof the rectrices.Again. in thesedifferences, the Midwaybird matchedthe Common rather than the Oriental Cuckoo. The bestways to separateCommon and Oriental cuckoosin the hand are by the amount of barring on the carpal covertsand the pattern of the underwingcoverts (Parkes 1990, Kennerleyand Leader 1991). areas that were not observedon the Midwaybird. Althoughthe Midwaybird matchedthe pale extremeof the Common Cuckoospecimens examined. there may be overlapin underpartplumage between C. c. telephonusand the Oriental Cuckoo, perhapsconfounded by age/sex-specific variation.The full range of this overlap,if it exists,has yet to be determined(M. R. Leven.P. J. Leader,and G. Carey pers.comm.). Thus, until a thoroughstudy is made, we feel it prudent to leave the specificidentity of the Midway bird indeterminate. Shouldthere prove to be little or no overlap in underpartplumage between Oriental Cuckoo and C. c. telephonus,however, we would feel confidentconsidering the Midway bird as the latter. In the western Pacific, the Common Cuckoo has been recorded in Palau but on no other islandsof Micronesia(Pyle and Engbring1985, Pratt et al. 1987, Reicheland Glass1991). whereasthe OrientalCuckoo has been recordedin Palauand Yap (Pyle 126 NOTES andEngbring 1985) andperhaps is the moreexpected species in the region(Pratt et al. 1987). Bothspecies reach Alaska rarely but regularly (Gibson and Kessel 1997). The Midwayrecord constitutes the firstfor thisgenus in the HawaiianIslands. A Yellow-billedCuckoo photographed on LaysanIsland on 1 November1994 (R. L. Pyle pers. comm.)constitutes the only other recordof a cuculiformin theseislands. We thankOceanic Society Expeditions and the U.S. Fishand WildlifeService for facilitatingour presenceon Midway, which was convertedfrom a naval base to a NationalWildlife Refuge on 1 July 1997. Pylethanks Ned K. Johnsonand Barbara Steinof MVZ for permissionto examinespecimens there, R. L. Pylefor information on the Yellow-billedCuckoo, and G. Carey, D. D. Gibson,Steve N. G. Howell, J. P. Leader,and M. R. Levenfor reviewingthe manuscript.This is contribution744 of the Point ReyesBird Observatory. LITERATURE CITED Cramp,S., ed. 1985. Handbookof the Birdsof Europe,the MiddleEast, and North Africa,vol. IV. OxfordUniv. Press,Oxford, England. Gibson,D. D., andKessel, B. 1997. Inventoryof the speciesand subspecies of Alaska birds. W. Birds 28:45-95. Kennerley,P. R., andLeader, J.P. 1991. Separationof Cuckooand Oriental Cuckoo. DutchBirding 8:143-145. Parkes, K. C. 1990. Identificationof Common and Oriental cuckoos.Birding 22:191-193. Pratt, H. D., Bruner, P. L., and Berrett, D. G. 1987. The Birds of Hawaii and the TropicalPacific. Princeton Univ. Press,Princeton, N. J. Pyle,P., andEngbring, J. 1985. Checklistof the birdsof Micronesia.'Elepaio 46:57- 68. Redman,N. 1985. Photospot15: Oriental Cuckoo.Br. Birds 78:473-475. Reichel,J. D., and Glass,P.O. 1991. Checklistof the birdsof the Mariana Islands. 'Elepaio 51:3-10. Accepted 11 December/997 127 .