SHORT COMMUNICATIONS 665

torr’. Note that pores on the outer surface of the procedure is applied in exactly the same way (timing, eggshellare representedby colorlesscircles of varying concentration of solutions, etc.) to each egg. sizes. As can be concluded from Figure 1; counting of pores is a very simple matter. One of the dyed pores LITERATURE CITED was selected for examination with SEM (Fig. 2). As AR, A., AND H. RAHN. 1985. Poresin avian eggshells: can be seenfrom the micrograph,the procedureworked gas conductance, gas exchange and embryonic well even though the pore channel was mostly occlud- growth rate. Respir. Physiol. 6 1:l-20. ed. AR, A., C. V. PAGANELLI,R. B. REEVES,D. G. GREENE, The staining technique also provides information AND H. RAHN. 1974. The avian egg:__ water vauor about pore size. Forty-seven dyed pores were selected conductance,shell thickness and functional pore for measurementsof actual pore mouth area and the area. Condor 76:153-158. area of the correspondingcolorless circle on the stained HOYT, D. F., R. G. BOARD,H. RAHN, AND C. V. PA- eggshell.SEM images(scanning angle = 45”) were used GANELLI. 1979. The eggsof the : con- to measurepore mouth areaand a micrometer-equipped ductance, pore structure, and metabolism. Phys- light microscopewas used to measure the area of the iol. Zool. 52~438-450. colorlesscircles. Pore mouthswere assumedto be either SILYN-ROBERTS,H. 1983. BSE Z contrast imaging of circular or elliptical. The relationship between these uranium stained pores in the avian eggshell. J. two areasis given in Figure 3 where R2 = 0.629. When Microsc. (Oxf.) 130:11 l-l 14. the two outlying data points are deleted from the data TULLETT,S. G. 1975. Regulation of avian eggshell set, R2 increasesto 0.758. Probably contributing to porosity. J. Zool. (Lond.) 177:339-348. unexplainedvariation are difficulty in accuratelymea- TYLER,C. 1953. Studies on eggshells.II. A method suring actual pore area (note irregular shape of pore for marking and countingpores. J. Sci. Food Agric. mouth in Fig. 2) and influence of shell thickness on 41266-272. movement of dye solution through pore channels.Al- TYLER,C., ANDS. FOWLER.1979. The size, shapeand though all of the pores included in Figure 3 were from orientation of pore grooves in the egg shells of one eggshell,it is possibleto usethe procedureto make Rhea sp. J. Zool. (Lond.) 187:283-290. comparisons among eggshells from different eggs. However, such comparisonsare useful only when the

The Condor89:665-667 0 The CooperOrnithological Society 1987

NESTING OF THE ROSS’ AND BLUE-PHASE IN THE SAGAVANIRKTOK RIVER DELTA, ’

STEPHEN R. JOHNSON LGL Ltd., 9768 SecondStreet, Sidney, British Columbia V8L 3Y8, Canada

DECLAN M. TROY LGL Alaska ResearchAssociates, Inc., 505 W. Northern Lights Blvd., #201, Anchorage,AK 99503

Key words: Ross ’ Goose;blue goose;Snow Goose; nesting by Ross’ Geese (Chen rossii) and blue-phase nesting;populations: arctic Alaska. Snow Geese (hereafter blue geese).

Since 1980 we have been studyingthe small population ROSS’ GEESE (100 to 200 pairs) of Snow Geese (Chen caerulescens) Nearly all Ross’ Geese nest in the central arctic of nesting on Howe Island in the Sagavanirktok River Canada(Ryder 1972, McLandress 1983). The breeding delta, Alaska (Fig. 1). Our study has included (1) an range is predominately adjacent to the Queen Maud annual (1980 to i987) round-up-and banding of geese Gulf with some breeding records from Southhampton during the brood-rearing/molt period, (2) behavioral Island and the Hudson Bay coast (see summary in observations of molting geese during 1981, and (3) Bellrose 1976). Ross’ Geese typically nest in mixed behavioral observations of incubating geese during colonies with Snow Geese (Ryder 1972, Kerbes et al. 1984. During these investigations we documented 1983). In recent years the breeding population has in- creased (Kerbes et al. 1983) and their range has ex- panded, mostly eastwardto Snow Goosecolonies along I Received 24 September 1986. Final Acceptance 10 the west coast of Hudson Bay (Frederick and Johnson February 1987. 1983). Ross’ Geese have been found nesting on Banks 666 SHORT COMMUNICATIONS

I I I I I \ , \ / SON 170’E 1800 170% 1609V 15oow 14ow I3OOW IPO~W 75% I

‘O’=E

WRANGEL ISLAND

..y,;.. . \ KILOMETERS ,.,: 16yW lF+“W i 1400~ “. I I FIGURE 1. Location of the SagavanirktokRiver delta Snow Goose colony relative to neighboring colonies. The insert shows Howe and Duck islands within the delta. The road and causewaythrough the delta were constructedin 1986; thus they were absent during most of the study period discussedin this article.

Island subsequentto 1960 (T. W. Barry, Canadian eiders, and all were on or near a small Wildlife Service, pers. comm.). However, this species sparsely-vegetatedpatch of at the east end of has not been recorded nesting at the Anderson River the island. The Ross’ Goose flew overhead for several delta or the Kendall Island Snow Goose colonies.Ross ’ minutes and was joined by another Ross’ Goose, pre- Geese (two in 1981 and one in 1982) recently were sumably its mate. This represents the first known reported in the Wrangel Island Snow Goose colony, breeding attempt by Ross’ Geese in the United States. but so far there is no evidence of nesting (Stishov et al. 1985). BLUE GEESE The first record of a Ross’ Goose in Alaska was of Blue geese constitute a large but variable proportion an individual shot (from a flock of 30 possible Ross’ of Snow Goose colonies in central and eastern North Geese) in 1907 at the mouth of the Stikine River in America. The abundanceof this color morph decreases southeasternAlaska (Willett 1921). Other records of rapidly from eastern to western . Blue Ross’ Geese,all from northern Alaska, include an adult geeseare rare on BanksIsland but have been seenthere female banded by the U. S. Fish and Wildlife Service annually since 1960 (T. Barry, pers. comm.). Low num- (USFWS) in July 1976 near TeshekpukLake, four seen bers (four to eight pairs) have been found nesting at about 15 km NE of Teshekpuk Lake on 18 August both the Anderson River delta (first nest recorded in 1977 (Kessel and Gibson 1978) and one observed at 1963) and the Kendall Island (first sighting in 1958, the Canning River delta, in June 1980 (Martin and positive nesting in 1984) colonies (T. Barry, pers. Moitoret 1981). comm.). There is a single record of a blue goose on We banded an adult male Ross’ Goose, captured Wrangel Island, USSR (Palmer 1976:134). Prior to our with a flock of Snow Geese,in the SagavanirktokRiver studies, Alaska records of blue geesewere limited to delta on 19 July 1983. On 28 June of the following the intermittent occurrenceof one or two during summer, during a survey of Duck Island, Stephen R. springmigration in Fairbanksfrom 1963 through 1980 Johnsonflushed an incubatingRoss ’ Goose from a nest (Kesseland Springer 1966;Kessel and Gibson, unpubl. containing three eggs. Duck Island is a small (4 ha) records). sand and gravel island located approximately 1.6 km In 1980 a male blue goose was observed in the Sa- E of Howe Island. Other nestson Duck Island included gavanirktok River delta colony paired with a white- 23 Brant (Brunta berniclu),one Canada Goose (B. cun- phase Snow Goose. This mixed pair had five flightless udensis),25 Common Eiders (Somuteriu mollissima), goslings-three white-phase and two blue-phase. This 47 Glaucous Gulls (Larus hyperboreus),but no Snow appearsto be the first record of a breeding attempt by Geese.The Ross’ Goose nest and the nestsofthe Brant, a blue goosewest of Kendall Island. Concurrent with SHORT COMMUNICATIONS 667 our study, J. W. Helmericks (pers. comm.) observed S. Dept. Commerce), and StandardAlaska Production a blue goose summering near Smith Bay, i75 km W Company (SAPC). SAPC provided financial assistance of the SagavanirktokRiver delta. in 1981 and 1982. for the preparation of this article. We thank Debra K. and also cbserveda migrant on the Colville River delta Slaybaughof SAPC for her encouragementand com- in the spring of 1985. The Smith Bay mentioned ments. We also thank Tom W. Barry, John G. Cole, above also was paired with a white mate (J. W. Hel- Daniel D. Gibson, Dale R. Herter, Joe C. Truett, Benny mericks, pers. comm.) and probably nested in both J. Gallaway, and two anonymousreviewers for reading 1981 and 1982. and commenting on earlier versions of this paper. In late July 1981 the SagavanirktokRiver delta geese were captured and banded, including the adult male LITERATURE CITED blue gooseand the two blue-phasegoslings. It was im- BELLROSE,F. C. 1976. Ducks, geese and swans of possibleto identify with certainty the male and white- North America. StackpoleBooks, Harrisburg, PA. phase goslingsof the blue goose.The adult blue goose DZUBIN,A. 1979. Recent increasesof blue geesein and the two blue goslingswere all males. One of the western North America, p. 141-175. In R. L. Jar- goslingswas shot in December 1981 in the Sacramento vis and J. C. Bartonek [eds.], Management and Valley, . None of these blue-phasebirds has biology of Pacific Flyway geese.OSU Book Stores, been recaptured in the Sagavanirktok delta. In 1984 Corvallis, OR. two blue geese,one male and one female, were captured FREDERICK,R. B., AND R. R. JOHNSON.1983. Ross’ and banded. No blue goslingswere found and we have Geese increasingin central North America. Con- no evidence that these two birds were a mated pair, dor 85:257-258. other than their occurrencein the same brood-rearing KERBES, R. H., M. R. MCLANDRESS,G.E.J. SMITH,G. flock. W. BEYERSBERGEN,AND B. GODWIN. 1983. Ross’ These observationsfurther suggestthe possiblewest- Gooseand LesserSnow Goosecolonies in the cen- ward expansion of blue geesein North America (Dzu- tral Canadian Arctic. Can. J. Zool. 6 1:168-l 73. bin 1979). However, as discussedby McLandress and KESSEL, B., AND D. D. GIBSON. 1978. Statusand dis- McLandress (1979), the frequency of blue-phase in- tribution of Alaska birds. Stud. Avian Biology_. 1: dividuals among Snow Geese in the Pacific Flyway l-100. (0.02%) also can be at least partially explained by pe- KESSEL, B., AND H. K. SPRINGER.1966. Recent data riodic mutation of a single gene. Winter records of on status of some interior Alaska birds. Condor Snow Geese from the Sagavanirktok River delta are 68:185-195. predominately from California and New Mexico. Sur- MARTIN, P. D., AND K. S. MOITORET. 1981. Bird prisingly, the recovery of the Sagavanirktokdelta blue populationsand habitat use, Canning River delta, goosewas in California, where the blue morph is quite Alaska. Unpubl. report, Arctic National Wildlife rare, rather than in New Mexico, where there are more Refuge,U.S. Fish and Wildlife Service,Fairbanks, blue geese. AK. To date neither Ross’ nor blue geesecan be consid- MCLANDRESS,M. R. 1983. Temporal changesin hab- ered established as regular breeding birds in Alaska. itat selectionand nest spacingin a colony of Ross’ No Ross’ Geeseyoung were found in the delta in 1984, and Lesser Snow Geese. Auk 100:335-j43. and no further sightingsof this specieshave been re- MCLANDRESS.M. R.. ANDI. MCLANDRESS.1979. Blue- ported in Alaska. None of the blue geeseraised in the phase R&s’ Geese and other blue-phase geesein SagavanirktokRiver delta has been captured in sub- western North America. Auk 96:544-550. sequentbanding programs in the delta, but a blue goose PALMER,R. S. [ED.]. 1976. Handbook ofNorth Amer- was sighted there during early summer 1986 (R. M. ican birds. Vol. 2. Waterfowl (Part 1). Yale Univ. Burgess,pers. comm.). This bird was collared with the Press,New Haven. type of marker we have been using and was evidently RYDER,J. P. 1972. Biology of nesting Ross’ Geese. a returning bird, but its identity was uncertain. Ardea 60:185-215. We are grateful to the many biologists and friends STISHOV,M. S., V. I. PRIDATKO,AND V. V. BARANYUK. who assistedin the banding programs in the Sagava- 1985. New data concerningbirds on Wrangel Is- nirktok River delta and to our colleaguesfor use of land. Bull. Moscow Exam. Nature, Biol. Sec. 90: their unpublished information. Our research on the 40-48. WILLETT, G. 1921. Bird notes from southeastern geeseofihe SagavanirktokRiver delta has been sup- Alaska. Condor 23: 156-159. norted bv ARC0 Alaska. EXXON Production Com- iany, LbL Alaska Regearch Associates, National Oceanographicand Atmospheric Administration (U.