VOL. 43, NO. 3 (SEPTEMBER 1990) P. 275283 A 16-Year Record of Summer on Truelove Lowland, Devon Island, Northwest Territories, DONALD L. PATTIE’

(Received 31 July 1989; accepted in revised form 30 April 1990)

ABSTRACT. An annual census ofadult birds was conducted on the 43 km2 Truelove Lowland, Devon Island, N.W.T., Canada, in the summers of 1970-73 and 1978-89. Forty-three were seen during 16 years. Of these, 18 species bred regularly on or immediately adjacent to the lowland and 10 were occasional breeders. In addition 15 species were visitors. The highest annual number for most breeding specieswas two to three times that of their lowest numbers, but some regular breeding species had far greater extremes. Extensions ofthe breeding range of Pacific (Guviupucificu), Purple Sandpiper (Culidris maritima), Wheatear (Oenanthe oenanthe), and Water Pipit (Anthusspinolettu) to Devon Island are reported. It is suspectedthat Hoary Redpolls (Curduelishornemunnz] and Red Knots (Culidris cunutus) also nested there once each. A coefficient of detectibilityis presented for the 16 most frequently seen species. Synchronousfluctuations in Snow Bunting (Plectrophenux nivalis) and Lapland Longspur(Calcarius lupponicus) populations were observed. A possible replacement of Black-bellied Plovers(Pluvialis squuturolu) by Lesser Golden-Plovers (R dominicu) was detected. An abrupt disappearance of all colonies of breeding ArcticTerns (Sterna purudisueu) from the lowland was seen in 1989. Key words: arctic birds, numbers, census, populations, breeding range

RfiSUMfi. Au cours des ttts de 1970 & 1973 et de 1978 & 1989, on a effectut un recensement annuel des oiseaux adultes sur les 43 km2 de Truelove Lowland, dans l’île Devon situ& dans les T. N.-O. au Canada. Durant ces 16 ann&s, on a observt 43 espkces d’oiseaux, sur lesquelles 18 se reproduisaient rtgulikrementsur les basses terres elles-memesou dans les environs immtdiats, et 10 ttaient des reproducteurs occasionnels. De plus, 15 espbces y ttaient de passage. Le nombre annuel le plus tlevt pour la plupart des espbces reproductrices hitde deux A trois fois suptrieur &leurnombre le plusbas, mais pour certaines esphces qui se reproduisaient rtgulibrement,les extrêmesttaient beaucoup plus grands. On rapporte aussi l’ttendue des aires dereproduction dans l’île Devon, du huart II gorge noire d’Amtrique(Cavia pacifica),du btcasseau violet (Culidris maritima), du traquet motteux (Oenanthe oenanthe) et du pipit spioncelle(Anthus spinolettu). On soupçonne que les sizerins blanchstres (Curduelis hornemannl] et les btcasseaux maubtches (Calidris cunutus) ont aussi nicht une fois & cet endroit. On prtsente un coefficientde dttectabilitt pour les 16 espkces observees le plusfrtquemment. On a remarque desfluctuations synchroniques chez les populations du bruant des neiges (Plectrophenux nivalis) et du bruant lapon (Culcarius lupponicus). On a Cmis l’hypothbse d’un remplacement possible des pluviers argentes(Pluviulis squuturolu) par les pluviers dorts d’Amtrique (R dominicu). En 1989, on a observt une disparition soudaine dans les terres basses de toutes les colonies reproductrices de sternes arctiques (Sterna purudisueu). Mots clts: oiseaux arctiques, nombres, recensement, populations, aire de reproduction Traduit pour le journal par Ntsida Loyer.

INTRODUCTION from other nesting areasto the north, west, and most ofthe south by a 24 km long ocean shorelineand to theeast and Many of the previous studies of birds breeding in the High south by steep slopes or cliffs that rise 300 m to a barren Arctic have been cited by Bliss et al. (1973), Freedman and plateau virtually uninhabited by birds (Bliss, 1977). Svoboda (1981, 1982) and Elander and Blomqvist (1986). Post-glacial rebound following ice retreat brou ht the Hussell and Holroyd (1974) provided an annotated list of lowland above level.The upper limit ofthe 43 km B census birds observed on Truelove Lowland, Devon Island, area beside the plateau liesat 76 m ad.Here an eroded upper Northwest Territories, Canada, in the summers of 1966-69. marine limit datedat Ca. 9450 years B.P. (Barr, 1971) is easily Renaud et al. (1979) considered the breeding birds found recognizable. Most ofthe census area is no higher than 25 m during 1976 on a northern Baffin Island site. Custer and a.s.1. A combination of moraines and raised beach ridges Pitelka (1977) followed breeding densities of the Lapland impedes drainageand produces a multitude of shallow lakes Longspur (Calcarius lapponicus)for seven years near Barrow, covering 9.5 km2, or about 22’70, of the lowland. The low, Alaska. Ouellet (1990) updated avian zoogeography in the raised beachesand moraines form a seriesof approximately Arctic Islands. 20 “steps.” These are breached by only five small streams From 1970 to 1973 and again from1978 to 1989, we carried that drain the lakes and saturate several wet meadows. Wet out a complete summer census of Puelove Lowland meadows are also maintainedby meltwater flowing fromthe (75O41‘N, 84O35’W), one of five contiguous lowlandson the plateau to the east. northeastern coast of Devon Island (Fig.1). The census was Raised beaches, moraine tops, and barren rock outcrops initiated in conjunction with other research (Pattie,1977) and are the driest habitatsand together cover13% of the lowland, continued whenit became apparentthe results were unique. rock outcrops supporting dwarf heather and arctic willow This paper lists16 years of bird census results fromthat High cover 12070, cushion plant-lichen and cushion plant-moss Arctic site. cover8%, and lichen barrenon limestone pavement covers 4%. Saltwater marsh present along the coast covers STUDY AREA no morethan 0.5% of the area. The remaining40.5% is moist meadow (Muc and Bliss, 1977). Devon Island hasno permanent human inhabitants. The The interspersion of many different ecosystems and the 43 km2 auelove Lowlandis a largelyundisturbed and abundance of ecotones are a dominant feature of Truelove geographically discrete nesting site for birds. It is isolated Lowland. Here the land meets the sea and abundant fresh

‘Northern Alberta Institute of Technology, 11762 - 106 Street, Edmonton, Alberta, Canada T5G 2R1 @The Arctic Institute of North America 276 / D.L. PATTIE

JONES SOUND

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-ELEVATION 1908m

FIG. I. Detail of the relationship of 'Ruelove Lowland to neighbouring lowlands. The inset shows the major physiographic features of the study area. The dashed lines show the location of two sample transects censused repeatedly (see text). waterprovides a multitude of shoreenvironments. The eastern and western and Low and High Arctic populations extensive wetand moist meadows gradeup to thexeric beach of migrant birds. Eastern species of Eurasian origin, based ridge tops and down to brackishbays. Canadian shield upon bandreturns, include the Brant (Branta bernicla)and granitic rock outcrops come up against the sedimentary Arctic Tern(Sternaparadisaea). Others that may have arrived limestone. Pushed beachesand alluvial fans of boulders end from includethe HoaryRedpoll (Carduelis hor- abruptly in moist, vegetated meadows. The high, largely nemanni) and races of Red Knot (Calidris canutus) and unvegetated plateau with its cap of permanent ice drops Ringed Plover (Chamdrius hiaticula).The Yellow-billed Loon abruptly to the snow-free, relatively verdant lowland. (Gavia adamsii) and the Pacific Loon (G. pacvica) have Truelove Lowland is in a very interesting cusp between western origins. The Glaucous Gull (Larus hyperboreus), TRUELOVE LOWLAND SUMMER BIRDS / 277

White-rumped Sandpiper (Calidris fuscicollis),and Baird’s years’ data. We calculated CDs onlyfor species seenat least Sandpiper (C. bairdii) were all recognized by Renaud et al. 150 times and rounded off CDs to the nearest tenth. (1979) as High Arctic species. These sameauthors considered To test the repeatabilityof our counts, tworoutes, a the Water Pipit (Anthus spinoletta), Lesser Golden-Plover southern one of 9.5 km and a northernone of 10.4 km, were (Pluvialisdominica), and Pectoral Sandpiper (Calidris censused at two- or three-day intervals ten timesin 1982 and rnelanotos), all of which nested at least once on ’Ruelove eight times in1983. Dashed lines in Figure1 show the location Lowland, to be Low Arctic species. of these transects. These routes covered a portion of each major found on the lowland. Over the years we also conducted transectcounts on the contiguous lowlandsto see METHODS if melove Lowland wasa reasonably representative lowland. In 1981 we conducted astrip census onthe 12 km2 Each annual census took 3-16 days,depending upon Alexandra Fiord lowland on Ellesmere Island immediately weather and the numbers of observers.One to nine observers following a breeding pairs counton thatlowland by Freedman followed established routes set100 m apart. All of the counts (Freedman and Svoboda, 1981). Freedman’s count took 129 took place between mid-Julyand early August (lhble 1). The man-hours of observation; ours was completed in23. When mean distance walked each year was 349 km (S.D. 44) and we applied CDs our results ranged from identicalto the mean time to complete the annualcensus was 132 hours differences of no more than 10% for any species for which (S.D. 23). Since the large lakeswere scanned from their shores, Freedman counted at least 10 birds. On this basis it is safe the distance walked each yearwas considerably lessthan the to say that on arctic lowlands the strip census methods we theoretical 430 km that would have been walkedhad the 9.5 used yielded comparable results in much less time than a km2 of lakes not been present. breeding pairs census. The routes followed a spiral pattern moving inward from the outer limits of the lowland. During the first years the person on the innermost line recordedlandmarks and took RESULTS the outermost line next time; adjacent observers used him as a guide. Although the census area remained the same, The number ofadults seen inthe annual censuses and their during 1978-89 the individual routes were drawn on the breeding status appear in lhble 1. Records obtained at other detailed map of the lowland published by Muc and Bliss times of occasional visitors or of scarce or cryptic species (1977). We found it easier to follow the map than to keep that were overlooked during the censuses are marked with a constant pace and orientationwith the adjacent observer. an asterisk. These supplemental records were not included After 1978 the lowland was divided into a north and south in the annual totals but serve to indicate an occasional segment and, while still worked fromthe outside in, the south presence. half was censusedbefore thenorthern segment.Where Breeding range extensionsto Devon Island were confirmed practical, the camp vicinity served asthe start andterminus by finding nests with eggsor recently fledged young of Pacific of each observer’s daily route (Fig. 1). , Purple Sandpipers (Calidris maritima), Wheatears Repeated countson asample 5 km transect in 1972 revealed (Oenanthe oenanthe), and Water Pipits. Despite a failure to that birds were least visible during periods of precipitation, find nests or fledglings, distraction displays leadus to suggest high winds, and between 2100 and 0400 hours. Light was that both Hoary Redpolls and Red Knots nestedat least once. not a factor since at this latitude there is no sundown from These are also breeding range extensionsbut, since eggs or 20 April until 17 August. Therefore, censuscounts were cus- young werenot found, they appear inlhble 1 as visitors rather tomarily conducted between 0800 and 1900 hours Central than occasional breeders. Daylight Saving Timeand were delayedor terminated if there Although Pacific Loonswere first seen in 1985, their first was precipitation or winds of more than 15 knots. Because attempt at breeding was in 1988, when they succeeded in weather conditions and availability of observers varied,the hatching young. In 1989 they nested again on the shore of dates for initiating and completing the census were not the same lake that lies adjacent to the sea near the mouth constant, but all counts were completed within the 15 July of the ’Ituelove River. Red-throated Loons (Cavia stellata) and 10 August extremes. Although young birds were had never been seen to nest beside this lake. A single pair enumerated, only adult bird records were used to prepare of Purple Sandpipers hatched youngon therocky limestone Thble 1. shingle of Rocky Point on the northwestern point of the We attempted to identify and record the species, sex, and lowland in 1989. During each of three years the Wheatears age of each bird seen. An estimatethe right-angleof flushing nested in the same rockoutcrop near whereour census limit distance in 10 m intervals from the line of march was also intersected the Thelove River. Sightings of Wheatears by recorded.Proximity toand communication with other Hussell and Holroyd (1974) were within a few hundred metres observers prevented most count duplication. Because of this site. The Water Pipit nest found protected by an over- individual birds of different species were not visible to the hanging rock in a moist meadow in 1984 was 1 km upriver same extent during censusing, Emlen’s (1971) “coefficient from the mouth of the the ’Ituelove River. The site where of detectibility” (CD)was determined for the mostabundant we suspected the Hoary Redpolls nested was about 3 km species (lhble 2). The CD is an estimate of the fraction of upriver fromthe mouth of the ’Ruelove River.The suspected each species present that was actually counted and permits Red Knot nest site was along a high dry beach ridge about estimates oftotal numbers and densities. Because numerous 2 km below the mouth of the ’Ituelove River. sightings in each intervalat right angles to theline of march Large, noisy birds, birdsthat customarily sat on water, or were needed in CD calculations, we used 10 m intervals to those with a contrasting colour or pattern were easiest to 100 m, lumped 100-200 m observations, and pooled many see and thus had the largest CDs, whereas small,quiet, cryp- TABLE 1. Synopsis of annualcensusbirdadult on Ttuelove Lowland, Devon Island, N.W.T.,75O41'N,84O35'W (actualcount) 3 \ 1970 1971 1972 1973 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1988 1987 1986 1985 1984 1983 1982 1981 1980 1979 1978 1973 1972 1971 1970 P Species 22 Jul-6-hg 2-10 hg 16-21 JUIY 21-29 July 18-29 July 16-21 July 18-24 July 16-25 July 16-22 July 16-20 July 15-22 July 16-20 July 16-19 July 16-19 July 16-18 July 15-19 July r Yellow-billed LoonYellow-billed V 0 0 0 0 0 0 0 1 0 1* 0 0 0 1 0 0 Gavia adamsii !! 107 52 72 108 76 92 68 92R LoonRed-throated76 108 72 5255 107 71 6486 76 40 34 44 85 Ei Gavia steIlata Pacific Loon Pacific 0 0 0 0 0 0 0 0 0 0 0 3 0 2* 0 2 2 Gavia pacifica Northern FulmarNorthern V 0 0 0 0 0 0 0 1* 0 0 0 0 0 0 0 0 Fulmarus glaciaIis Brant 0 0 0 4 0 0 0 0 0 0 0 2 0 0 2 0 0 Branta bernicla G oose R Snow Goose 12 10 2 0 12 0 0 0 8 6 11 8 1 8 2 8 Chen caerulescens Oldsquaw R 172 142 225 297 305 21 1 198 232 214 189 249 152 191 189 191 152 249 189 214 232 198 1 21 305 297 225 142 172 R Oldsquaw 247 196 Clangula hyemalis Com mo n Eider R 12 7 166 63 79 63 166 7 12 R 30 Eider Common 4 10 19 42 46 77 4 76 32 13 Somateria mollissima King Eider R 4 51 20 75 41 2558 42 24 25 32 21 31 12 5 1 Somateria spectabih Unidentified female eider female Unidentified 34 45 Somateria sp. 1 2* 1 3 2* 1 3 3 1 RockR3 Ptarmigan 3 10 1 3 2* 0 3 2 1 0 2* 0 1 2 Lagopus mutus Peregrine Falcon R FalconPeregrine 0 0 0 6* 0 1 0 3* 0 3 4* 2 I* 3* 0 5* Falco peregrinus 6 4 28 23 13 9 14 34 25 22 33 20 33 22 2*25 Golden-PloverR34 Lesser 14 9 13 23 0 28 0 4 0 6 Pluvialis dominica Black-bellied Plover R 12 10 31 23 24 31 24 24 18 16 9 18 11 4 11 4 11 4 11 18 9 16 18 24 24 31 24 23 31 10 12 R Black-belliedPlover Pluvialis squatarola Ringed Plover 0 0 2 0 0 0 0 0 3* 0 0 0 0 0 0 0 0 Charadrius hiaticula Ruddy Tbrnstone R Tbrnstone Ruddy 2 13 220 18 11 23 31 6 0 13 2 34 378 13 Arenaria interpres Red Knot V(O?) 16 0 1 0 25 016 11 0 65 3 11 2324 11 6* Calidris canutus Purple Sandpiper Purple 07 20 5 9 24 0 0 3 0 0 0 22 0 2* 0 1 Calidris maritima Pectoral SandpiperPectoral 0 0 0 0 0 0 0 0 0 0 1 0 1 0 0 0 0 CaIidris melanotos 40 25 31 49 68 15 63 22 3 13White-rumped 314 Sandpiper 2214 R 63255 156 68 49 31 255 40 Calidris fuscicollis 35 68 13 24 95 129 111 187 25 1 25 187 111 129 RSandpiper 95Baird's 24 13 68 35 167 239 189 133 197 210 391 Calidris bairdii Sanderling V 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 Calidris alba Dowitcher V 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 Limnodromus sp. 6 6 15 41 51 2 6 21 11 16 16 16 11 21 6 2 51 41 Red Phalarope15 R 6 6 3* 7 15 2 10 Phalaropus fulicarius Pomarine JaegerPomarine V 0 0 0 0 0 0 0 0 0 0 0 0 1* 0 0 0 Stercorarius pomarinus 10 11 30 17 7 14 9 11 9 R 14 Jaeger Parasitic 7 17 30 24 11 8 10 4 7 12 8 6 8 Stercomrius parasiticus (continued) TABLE 1 - Continued

1970 1971 1972 1973 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 19891988 1987 1986 1985 1984 1983 1982 1981 1980 1979 1978 1973 1972 1971 1970 Species 22 J~l-C-hg 2-10 hg 16-21July 21-29 July 18-29July 16-21 July 18-24 July 16-25 July 16-22 July 16-20July 15-22 July 16-20July 16-19 July 16-19 July 16-18 July 15-19 July Long-tailed Jaeger22 0 13 88 3862 35 111 14750 12432 43 58 105 33 72 Stercorarius longicaudus Thayer's Gull V 0 0 0 0 0 0 0 0 3* 0 0 0 0 0 0 0 Lam thayeri Glaucous Gull R 62 57 30 4092 67 109 115 100119 54 83 67 88 85 91 Lam hyperboreus Ivory Gull V 3* 1* 0 0 0 0 0 0 0 1* 7' 2* 0 0 0 0 Pagophila eburnea Black-legged Kittiwake V 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 Rka tridactyla Sabine's Gull V 0 0 1 0 1 0 0 0 0 0 1* 0 0 0 0 0 Xema sabini Arctic %rn R 93 57 51 10565 83 91 140 90119 93 74 87 64 45 1 Sterna paradisaea Black Guillemot V 2* 2* 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Cepphus grylle Snowy Owl V 0 1 0 0 l* 1 0 1* 0 Nyctea scandiaca Horned Lark 0 0 5 9 2 0 10 2 0 0 Eremophila alpestris Barn Swallow V 0 0 0 0 1 1 0 0 0 Hirundo mtica Water Pipit 0 0 0 0 0 0 0 4 0 0 Anthus spinoletta Common Raven 0 0 6 0 1 2* 2 3 4 2* CONUS COMX Wheatear 0 l* 0 8* 2* 0 0 0 0 0 Oenanthe oenanthe Hoary Redpoll V (O?) 0 1* 0 1' 0 0 1* 0 0 Acanthis hornemanni Savannah Sparrow V 0 0 0 0 0 0 0 0 0 Passerculus sandwichensis 4 62 50 41 49 101 87 76 154 153 193 224 207 141 74 83 78 83 74 141 207 224 193 153 154 76 Longspur87 Lapland 101 49 41R 50 62 F Carcarius lapponicus C Snow Bunting R Bunting 42 Snow 230 241 377 307 138 74 221 5681 721 645 551 60457 220 356 Plectrophenax nivalis Total Adult Birds 7098811127 877 1259 1462 1513 1614 2007 1803 1697 904 1247 1255 1575 1480 s * Birds seen on study area outside of census periods; not included in totals. R Regular breeding species. 3 0 Occasional breeding species. % V Visiting species. U

\ 280 / D.L. PATTIE

TABLE 2. Coefficients of detectibility forTruelove Lowland birds tically patterned species hadthe smallest CDs (Table2). Table calculated from census period data 3 provides an indication of the constancy with which birds were encountered during repeated counts along the two routes Species Coefficient of detectibility (CD) shown as dashed linesin Figure 1. These counts together with Red-throated Loon Cavia stellata 0.9 the CDs provided indications of short-term variation in the Oldsquaw Clangula hyemalis 1.o presence or visibility of different species. Dataobtained from Common Eider Somateria mollissima 1.0 the test routes for the two periods immediately precedingthe King Eider Somateria spectabilis 0.8 Lesser Golden-Plover Pluvialk annual censusare presented in Thble 3. Results fromthe week dominica 0.9 immediately before the annual census were our first choice Black-bellied Plover Pluvialis for comparative purposes.After 25 July adult Snow Buntings squatarola 0.9 Ruddy Turnstone Arenaria interpm 0.9 and Lapland Longspurs began molting remigesand rectrices, White-rumped Sandpiper Calidris and the test route data confirmed that they then became fuscicollis 0.5 secretive(Green and Summers, 1975; Pattie, 1977). This Baird’s Sandviver Calidriv bairdii 0.9 Red PhalaropgPhalaropus fulicarius 0.9 behaviour may have reducedthe numbers of these two species Parasitic Jaeger Stercorarius counted in 1970, 1971, 1973, and 1978, when the censuses pamsiticus 0.6 were not completed until molt was under way. Long-tailed Jaeger Stercomrius Annual variation in total numbers of birds of all species longicaudus 0.6 Glaucous Gull Lams hyperboreus 0.8 (Fig. 2) was tested with a correlation matrix among years. Arctic Tern Sterna pamdisaea 0.1 The 1981 results correlated strongly (r = 0.92, n = 16, oc Lapland Longspur Calcarius = 0.001) with the results of all years except 1971, 1972, and lapponicus 0.6 Snow Bunting Plectrophenax nivalis 0.1 1973. The lowest correlations were between those of 1972

~ ~~ and the other years.

TABLE 3. Results of duplicate counts along specific transects

9.5 km southern route 10.4 km northern route 1982 1983 1982 1983 1982 12 July 14 July 10 July 13 July 12 July 14 July 12 July 15 July Red-throated Loon 4 12 5 14 4 4 I I Cavia stellata Oldsquaw 41 30 18 20 I I 18 18 Clangula hyemalis Common Eider 2 3 0 12 2 11 2 0 Somateria mollissima King Eider 3 2 2 2 3 12 Somateria spectabilis Lesser Golden-Plover 4 5 Pluvialk dominica Black-bellied Plover 1 5 10 10 1 1 Pluvialis squatarola Ruddy Turnstone 3 8 1 0 Arenaria interpres Red Knot 0 2 Calidris canutus White-rumped Sandpiper 0 3 4 8 1 1 Calidris fuscicollis Baird’s Sandpiper 1 I 3 6 0 2 2 1 Calidris bairdii Red Phalarope 1 0 Phalaropus fulicarius Parasitic Jaeger 1 2 2 3 Stercomrius pamsiticus Long-tailed Jaeger 5 15 5 10 3 5 4 8 Stercomrius Iongicaudus Thayer’s Gull 2 1 Lams thayeri Glaucous Gull 9 14 I 6 4 2 3 1 Larus hyperboreus Arctic Tern 20 25 34 31 4 3 3 0 Sterna pamdisaea Snowy Owl 0 1 Nyctea scandiaca Common Raven 0 4 Corvus corn Lapland Longspur 5 11 16 21 8 11 9 I Calcarius lapponicus Snow Bunting 8 11 22 24 11 12 29 25 Plectrophenax nivalis TRUELOVE LOWLAND SUMMERBIRDS / 281

Adult Birds CountedOn Truelove Lowland AnnualPlover Counts 2. I j, I 35 1.8 30 1.7 1.6 1.5 25 1.4 1.3 h 8 1.2 f 20 6 1.1 * E 21 0.9 15 0. a 0.7 0.6 10 0.5 0.4 0.3 5 0.2 0. I 0 0 ...... m71n7374?57~777879'BD0182~04rn86078889 rn71n7374757677~79rn0182~a4858687~~89 Year veal) Lesser muen- Block-bellEd

FIG. 2. Total adult birds counted during the annual censuses on "helove FIG. 4. Pattern of abundance of two species of plovers showing how the Lowland, Devon Island. apparent invasion of Lesser Golden-Plovers and their populationgrowth appears to coincide with a decline in Black-bellied Plover populations. Lapland Longspur and Snow Bunting (Plectrophenax nivulis) populations appeared to fluctuate synchronously on the other four nearby lowlands.The increased edge effect, (Fig. 3). This was tested usingthe Spearman rank correlation interspersion, habitat diversity, moister conditions brought (rs). The result indicated a high degree of synchrony (rs = about by the comparatively low relief and blocked drainage, and greater vegetative coveron 'Thelove are the most visible 0.83, a = 0.001, n = 16). On the other hand, populations of Black-bellied Plovers (Pluviulis squuturola) and Lesser causes of the differences among the lowlands. Based upon Golden-Plovers illustrated negative correlation for the years plant associations, a warmer microclimate must exist near the mouth of the Truelove River. This may be the result of both were present in the census (Fig. 4) (rs = -0.533, a = 0.05, n = 12) as well as for the entire16 years (rs = -0.443, reflection of the sun by nearly intersecting cliffs. It was in = 0.05, n = 16). this area that all but one of the nests representing breeding oc range extensions were found. aoo The coefficients of detectibility reported in Table 2 may now be usedto estimate actual numbers from data obtained 700

FIG. 3. Comparativeabundance of adultSnow Buntings and Lapland Fluctuations in Numbers Longspurs showing pattern of population fluctuation. After 1978, when we adopted a uniform mid-July timing for the census, there was only a slightly more than twofold DISCUSSION variation in the total numbers of all adult birds, but the long- Density and Diversity term amplitude of fluctuation in numbers varied among species. Suchaquatic species as the Arctic Tern, Red-throated The density and diversity of birds listed in Table 1 were Loon, and Oldsquaw exhibited onlya threefold extreme in far lower than one wouldfind in a temperate clime with com- numbers until 1989, when the entire breeding population of parable habitat diversity. But Truelove Lowland had far higherArctic Rrns failed to appear. Breeding populations of Baird's bird densitiesand much greater species diversitythan found Sandpipers and Red Phalaropes (Phaluropus fulicurius) 282 / D.L. PATTIE exhibited perturbations of 30 and 25 times respectively of ACKNOWLEDGEMENTS their low numbers. Common Eiders, King Eiders,Red Knots, and Long-tailed Jaegers, whichin some years consisted mostly Over the years ofthis project, many people assisted with the annual of mobileflocks of nonbreeders, also often revealed extreme census and this paperwould not have been possible without their annual fluctuations. Other regularly seen specieshad long- help. To the technicians Sandra Abraham,David Blaha, EricBlake, term fluctuations between 3 and 25. Not allpopulations rose Steve Flindall, Buster Gilbert,Steve Golub, Bruce Grahn, Colleen and fell synchronously. Harlton, Barry Kolenowski, Ron Lett, Karen Meikle, Anton Melnyk, Rod and BarbaraMoore, Galen Pittman,Lindsay Rackette, Andrew Snow Bunting populations may have been depressed by Rowsell, Jim Trask, Allen’hutman, Pat Vos, Susan Westover, and some scientific collecting prior to 1970 and more intensive Ken Zurfluh andsuch capable volunteersas Stuart Alexander, Owen collecting in conjunction with bioenergetic studiesin 1970-72. Atkin, Ludo Bogaert, JodyButler, Jennifer Chanter,Peter Demulder, We saw evidence ofInuit hunting birds on thelowland only ArveElvebakk, Chuck Gordon, Dave Hackett, Norma twice during the study but, based upon the few spent car- Haubenstock, Albert, Pirkko, andVireo Karvonen, Claude Labine, tridges found, assumed it unlikely that they took many birds. Rob Lenniham, Jan Marsh, Jennie McCallum,Peter Nosko, Carroll Perkins, Raymond Prach, CharlieRumsey, Jim Ryan, ChrisSomr, Competition among Plovers Peter Strahlendorf, A1 Smith, Raphael Villar, Rob Young, plus a The driest sandy or gravelly beach ridgesor moraine tops host of others who helpedus, fed us when we returned from long periods of counting or did our camp chores, I express sincere provided nesting sites for Black-bellied Plovers. Adjacent, gratitude. slightly hummocky vegetatedareas on thesides ofthe lower Early parts of the studywere funded by NRCC grantno. A6135 ridges were used by Lesser Golden-Plovers.The Black-bellied and were also supported by grants to the InternationalBiological and Lesser Golden-Ploverpopulations are difficult to analyze. Program. The Arctic Instituteof North America contributed both Black-bellied Plovers were initially more numerous but, as financial and field support, thanks whichfor are directedto Gerry the Lesser Golden-Plovers became more numerous, Black- Thompson andPeter Schledermann. The CanadianWildlife Service bellied Plover numbers declined.The Spearman rank corre- supported the 1988 field work and contributed manpower and lation analysis showed negativecorrelation for the two popu- supplies to the program. lations at the 10% level of confidence, suggesting species None of the work could have taken place without Polar Con- replacement or competition may have been taking place. tinental Shelf Project grants to project111-80 from Energy Mines and Resources. George Hobson, Fred Alt, Jim Goddin, Frank Hunt, Hussell and Holroyd (1974) saw sevenadult Lesser Golden- and Barry Hough, representatives of the Polar ContinentalShelf Plovers and reported one nest in 1967. They saw single birds, Project, deserve thanksfor providingrepairs, transportation, but noevidence ofbreeding, on five dates in 1966,1968, and equipment, and their special hospitality in Resolute. 1969. None was seenin 1970-73, although a pair was reported Stuart Alexander, R. Bromley,G.L.Holroyd, D.J.T. Hussell, Robin in late June 1970. From 1978 through 1988, however, nesting Leech, W. Bruce McGillivray, and E.C. Pielou offered suggestions occurred each year. Their numbers increased substantially for improving the manuscript. I am grateful for their help. in 1980. That year Lesser Golden-Plovers were seenpursuing Black-bellied Plovers on three occasions. Since 1980, there have been further observations of Lesser Golden-Plovers REFERENCES pursuing Black-bellied Plovers. In noinstance was a Black- bellied Plover seenpursuing a Lesser Golden-Plover. These BARR, W. 1971. Postglacial isostatic movementin northeastern DevonIsland observations suggest competition. Lesser Golden-Plovers A reappraisal. Arctic 24249-268. actively defendeddry beach ridgesadjacent to their own nest BLISS, L.C. 1977. Introduction. In: Bliss, L.C., ed. ’helove Lowland, Devon sites against Black-bellied Plovers that nested only on the Island, Canada: A High Arctic Ecosystem. Edmonton: University of Alberta Press. 1-11. dry beach ridges. Both species occupiedadjacent wet meadow , COURTIN, G.M., PATTIE, D.L., RIEWE, R.R., WHITFIELD, areas after hatching. The frequent nesting by Lesser Golden- D.W.A., and WIDDEN,P. 1973. Arctic ecosystems. AnnualReview Plovers at this latitude either callsinto question the placement of Ecology and Systematics 4359-399. of this species in the category of a Low Arctic species by CUSTER, T.W., and PITELKA, EA. 1977. Demographic features of a (1979) Lapland Longspur population near Barrow, Alaska. Auk 94505-525. Renaud et al. or it suggests that the transition zone ELANDER, M., and BLOMQVIST, S. 1986. Theavifauna of central between Low and High Arctic is much broader than they Northeast Greenland, 73°15’N-74005’N, basedon a visitto Myggbukta, propose. It is also possiblethat thetransition zone hasmoved May-July 1979. Meddelelser om Grmland, Bioscience 191-44. north since 1976. EMLEN, J.T. 1971. Population densitiesof birds derived from transect counts. Auk 88~323-342. FREEDMAN, B., andSVOBODA, J. 1981. Populations of breeding birds SUMMARY at Alexandra Fiord, compared with other High Arctic localities. In: Svoboda, J., and Freedman, B., eds. Ecologyof a High Arctic Lowland The work reported here providesa long-term record of bird Oasis, Alexandra Fiord (78O53’N, 75O55‘W), Ellesmere Island, N.W.T., populations at a discrete High Arctic site. Breeding range Canada. Toronto and Halifax: Botany Departments, Universityof Toronto extensions for 4 species were documented. Populations of and Dalhousie University. 206-215. SnowBuntings and LaplandLongspurs fluctuated syn- . 1982. Populations of breeding birds at Alexendra Fjord, Ellesmere Island,Northwest Territories, compared with other arctic localities. chronously during the 16 years. Those of Lesser Golden- Canadian Field Naturalist 9656-60. Plovers and Black-bellied Plovers exhibited an inverse rela- GREEN, G.H., andSUMMERS, R.W.1975. Snow Bunting moult in tionship after the LesserGolden-Plovers reoccupied the Northeast Greenland. Bird Study 229-17. lowland. The total magnitudeof long-term variation in HUSSELL, D.J.T., and HOLROYD, G.L. 1974. Birdsof Truelove Lowland numbers of adult birds was between two and three times. and adjacent areasof northeastern Devon Island, N.W.T. Canadian Field- Naturalist 88:197-212. Adult numbers of some species remained relativelyconstant MUC, M., and BLISS, L.C. 1977. Plant communitiesof Thelove Lowland. from year to year but those of other species fluctuated by In: Bliss, L.C., ed. Truelove Lowland, Devon Island, Canada: A High much greater magnitudes. Arctic Ecosystem. 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OUELLET, H. 1990. Avianzoogeography in the Canadian arctic islands. Canada: A High Arctic Ecosystem. Edmonton: University of Alberta In:Harrington, C.R., ed. Canada’s Missing Dimension. Vol. 11. Ottawa:Press. 413-435. CanadianNature. Museum of 516-543. RENAUD,JOHNSON,W.E., S.R., HOLLINGDALE,and P.D. 1979. PATTIE, D.L. 1977. Population levels and bioenergetics of arctic birds on Breeding birds of Arctic Bay, Baffin Island, N.W.T.,with notes on the Thelove Lowland.In: Bliss, L.C., ed. melove Lowland,Devon Island, biogeographic significance of the avifauna. Arctic 32122-134.