First Record of Black Noddy Nesting at Kure Atoll--During 13-15 July 1982 I Visitedgreen Island,Kurc Atoll, to Assistwith a Surveyon Wildlifestatus and Distribution
Total Page:16
File Type:pdf, Size:1020Kb
66] GeneralNotes J.Field WinterOrnithol. 1985 was$6.$øC (35.0-37.5, n -- 9) or only 10% lessthan the meanbody temperature $9.4øC ($8.6-40.0, n = 6) of incubatingfemales on the studytract; a situationsimilar to that in young Great-HornedOwls when they becomeefficient thermoregulators (Turner and McClanahan1981). Nestlingplumage developments that might affectthermoregulation abilityare the unfurlingof the prepennaceousdown over muchof the bodybeginning at aboutage 7 daysand the unfurlingof the tipsof the contourfeather quills, especially on the wings,scapulars, and dorsaltract, beginningat aboutage 14 days. When FloridaScreech-Owls achieve temperature regulation at about 14-16 daysof age at a meanweight of 72-84 g (n -- 15, Lohrer, unpublisheddata), they are similarin certainaspects of developmentto CaliforniaGreat Horned Owlsthat achievetemperature regulationat 28 daysof age at a weightof about 700 (88)or 1000 (•) g (Turner and McClanahan1981). Both speciesbecome efficient thermoregulators at about halfway throughtheir respectivenestling periods. In addition,both speciesare closeto or have just reachedpeak nestlingweights (Otus 80-93%, sexescombined; Bubo 95% 88, 100% •), and both are about sAof adult weight (Otus66-75% of 109 g, O. a. floridanus,sexes combined,Lohrer, unpublisheddata; Bubo70% of 991 g c•, 76% of 1312 g •, B. v. pacificus,Earhart and Johnson 1970, Condor72:251-264). The developmentof ther- moregulationability at aboutthe samenestling stage in these2 speciesof greatlydifferent sizesuggests that this maybe a generalpattern for owls.However, more data are needed from intermediate-sizedowl speciesto confirm this SUggestion.--FRzDE. LOVIRER,Archbold BiologicalStation, P.O. Box 2057, LakePlacid, Florida 33852. Received6 July 1983;accepted 5 Nov. 1984. First Record of Black Noddy Nesting at Kure AtolL--During 13-15 July 1982 I visitedGreen Island,Kurc Atoll, to assistwith a surveyon wildlifestatus and distribution. I recordedBlack Noddies(Anous minutus) nesting; this is the first recordednesting of BlackNoddies at Kurc Atoll, althoughthey breed on mostisland groups in the tropical Pacificand neston mostof the leewardHawaiian Archipelago islands (Berger 1981). Background.--KurcAtoll is the farthestnorthwest atoll in the HawaiianArchipelago. Green Islandis the only inhabitableisland in Kurc Atoll; the other islandsof the Atoll are little more than sandbarswhich vary in sizeand shapeover the years. Green Islandis dominatedby the U.S. CoastGuard LORAN Station,built in 1960- 1961 and continuouslyoccupied since 1961. The stationincludes an airplanerunway, a 191 m antennatower, and a varietyof supportfacilities and crew quarters.Prior to this, the only major disturbanceby humanswas in 1955 when a radar reflectorwas built on Green Island. Before 1957, there were only two populationestimates for BlackNoddies on Green Island;neither reportednesting birds (Woodward 1972). In June 1957, Kenyonand Rice (1958) found "no indicationof nesting"although 44 adultswere seen. The mostcomprehensive seabird inventory at Kurcoccurred from 1963 to 1969during the PacificOcean Biological Survey Program (POBSP). Black Noddies were then recorded asvisitors in all monthsof the year,although generally absent from late Decemberthrough mid-March.Peak numbers occurred from May to September,with a maximumestimate of 2000 in June andJuly of 1967. Although iramaturesas well as adultswere recorded roostingon GreenIsland, and at least3 adultswere seen molting with bare brood patches in 1967, Woodward(1972) said"No indicationthat this speciesbred at Kurc wasnoted duringPOBSP studies." He further speculatedthat the BlackNoddies at Kurc werepost- breedingbirds from MidwayAtoll, where "thousandsbreed," mainlyin the winter. Various biologistsrepresenting the Hawaii State Divisionof Forestryand Wildlife (DOFAW) havevisited Kurc Atoll. Nine trip reportsand one letter in the filesof DOFAW in Honolulu summarize seabird observations from short visits which occurred from 1967 to 1982. No visitswere reported from the monthsof January,August, October, or No- vemberduring those years. In one or more of the years,Black Noddies were seenin the other months,except for May 1973 whenthe biologiststated that no BlackNoddies were seen.The reportsfrom March 1967, April 1978, and December1977 (Walker 1977) specificallystate that chicksand/or eggsand/or nestswere notnoticed. Vol.56, I•o. 1 GeneralNotes [67 On 14 July 1982, I sawapproximately 80 adult or fully-featheredBlack Noddies; somewere on nestsand chicks.Nests were in tree heliotrope(Tournefortia argentata) south of the runwayand in ironwoodtrees (Casuarinaspp.) behind the pumphousenear the Northwest Beach. In June 1983, another Divisionwildlife biologistreported someBlack Noddieson nestsin tree heliotrope south of the airport runway, but no nestswere noticed in the ironwoodtrees aroundthe buildings(Ralph Saito, DOFAW, pers.comm.). Elsewherein the HawaiianArchipelago, Black Noddies are reportedto neston "shrubs, trees,on rock ledges,in cleftsof rocks,or holesin cliffs"(Berger 1981). They build a nestwith grass,twigs, leaves, and/or seaweed.On Midway,Laysan, and Lisianskiislands in the northwestchain, they are reportedto neston ironwoodbranches; on Laysanthey also nest on naupakabushes (Scaevola), Pluchea, clumps of bunchgrass(Eragrostis), and coconuttrees (Cocos nucifera) (Ely and Clapp 1973). The nestingseason in other parts of the northwestchain is apparentlyprolonged and/or variable.Black Noddies are reportedas nesting from January to Juneon Lisianski (Clappand Wirtz 1975), from Novemberto July on Laysan(Ely and Clapp 1973) and on NeckerIsland in everymonth of the year,although not in all monthsevery year (Clapp and Kridler 1977). Therefore, July nestswith chickson Kure are consistentwith obser- vationsfrom other nearbyislands. Discussion.--GreenIsland, Kure Atoll, is a flat coral islandwith no rocky cliffsor ledgeswhich could be usedas nest sitesby Black Noddies.The commonnative shrub naupakaevidently does not providesufficiently attractive nest sites, although it is usedfor BlackNoddy nestingon other nearbyislands. Visitingbotanists have documented significant vegetative changes on Green Island, Kure Atoll, coincident with the advent of man-caused habitat alterations. Green Island receiveda largeinflux of non-nativeplants: especially accidentally introduced weed species anddeliberately introduced ornamentals, beginning in the mid-1950's during construction andhuman habitation. Some weedy species were probablybrought in asseed on construc- tion equipmentor in soilof pottedplants. Lamoureux (1961) reported22 speciesof newly introducedweeds and cultivatedplants present immediately after the LORAN Station wasconstructed. Among thesenewly recorded plants were shadeand ornamentaltrees or tree-like species:hala (Pandanusodoratissimus), coconut trees, and someof the iron- woods.Other ironwoodsevidentally were introducedaround 1955 when the radar re- flector wasbuilt (Woodward1972, Clay 1961). The tree heliotrope,which occursas a shrubbytree just behind the beach,was first recordedin October of 1959 (Clay 1961, Christophersenand Caum 1931). It is the only tree specieson Green Islandwhich may haveestablished itself there without the aidof man(Carolyn Corn, DOFAW, pers.comm.). Another three tree specieshave been planted on Green Island sincethe early 1970's: Norfolk Islandpine (Araucariaheterophylla), Madagascar olive (Noronhiaemarginata), and seagrape (Coccoloba uvifera) (Carolyn Corn, DOFAW, pers. comm.). Of the sevenintroduced tree or tree-likespecies on Green Island,the tree heliotrope and ironwoodtrees apparently represent new nestinghabitat into whichBlack Noddies have lately expandedtheir breedingrange, althoughnesting habitat which is adequate on other islands(e.g., naupaka bushes) has been available for manyyears. Summary.--BlackNoddies (Anous minutus) were first noticedand reported as nesting on Green Island,Kure Atoll, on 14 July 1982; the nestswere situatedin tree heliotrope and ironwoodtrees. Seven tree or tree-likespecies, none of whichoccurred there in 1923, nowoccur on Green Island.All of thesespecies, except possibly the tree heliotrope,were brought to the islandon or after 1955 as intentionalor accidentalintroductions. This habitat alteration has apparentlycreated new nestinghabitat on this fiat coral island; althoughthe nativenaupaka bush is usedon other islandsfor nestingBlack Noddies, it hasnot yet been recordedas a nestsite substrateon Green Island. Acknowledgments.--Ithank R. L. Walker, M. Naughton, R. Clapp, and C. Corn for their reviews,and my employer,the Hawaii Div. of Forestryand Wildlife, for sendingme to Kure. I alsothank Derral Herbstand CharlesLamoureux for developing,along with C. Corn, the 1979 plant list for Green Island, Kure Atoll. 68] GeneralNotes J.Field Ornithol. Winter 1985 LITERATURE CITED BERGER,A.J. 1981. Hawaiianbirdlife. UniversityPress of Hawaii, Honolulu,Hawaii. CHRISTOPHERSEN,E., ANr• E. L. CAUM. 1931. Vascularplants of the Leeward Islands, Hawaii. BerniceP. BishopMus. Bull. 81:1-41. CLAPP,R. B., ANDE. KRIDLER.1977. The naturalhistory of NeckerIsland, Northwestern Hawaiian Islands. Atoll Res. Bull. No. 206. •, ANr•W. O. WIRTZ,II. 1975. The naturalhistory of LisianskiIsland, Northwestern Hawaiian Islands. Atoll Res. Bull. No. 186. CLAY,H. F. 1961. Narrative report of botanicalfield work on Kure Island, 3 October 1959 to 9 October 1959. Atoll Res. Bull. No. 78:1-4. ELY,C. A., ANDR. B. CLAPP.1973. The naturalhistory of LaysanIsland, Northwestern Hawaiian Islands. Atoll Res. Bull.