Census of seabird colonies on Nordaustlandet , Svalbard, and in neighbouring localities in 1978 and 1979 PALLE UHD JEPSEN AND A R E M O B E K Jepsen, P. U . & Mobak, A . 1983: Census of seabird colonies on Nordaustlandet. Svalhard. and in neighhouring localities in 1978 and 1979. Polar Research 1 n . s . . 199-209. Seabird colonies were censused during the summer expedition of Norsk Polarinstitutt to Nordaustlandet. Svalbard, in 1978 and 1979, and to Kongs~ya in 1979. An outline is givcn of thc distribution of the ,pecir, together with an estimate of the number of breeding pairs in the colonies. Twenty-five colonies were ccnsused; seven were visited both years. Four colonies with more than 1,000 breeding pairs of the most abundant species, Brunnich‘s guillemot and kittiwake, were found on Nordaustlandet. Palle U h d Jepsen, Vildtreseruarkontoret, 8410 Rmnde, D e n m a r k : A r e Mobcek, Fylkesmannen i H e d m u r k . H e d m a r k Fylkeshus. 2300 Hamur. Norway; October I981 (reciised June IYX.3). Introduction The seabird colonies in Spitsbergen, particularly those in the western fjords and o n Prins Karls Forland, have been investigated and described by Lovenskiold (1964), Larsen (1965), and Norder- haug (1967,1974). Norderhaug et al. (1977) men- tion that seabird colonies of more than 1,000 breeding pairs are unlikely on Nordaustlandet. They also state that colonies of between 1,000 and 10,000 birds have been registered by Lovenskiold (1964) among others on the islands and coasts of Hinlopen. A single colony on Alkefjellet had more than 100,000 birds. O n Kong Karls Land. between 1.000 and 10,000 seabirds have been registered in two colonies. Not until lately, in connection with the summer expeditions of Norsk Polarinstitutt (NP), have quantitative and qualitative data been collected from the sea- bird colonies on Nordaustlandet, the surrounding islands, and on Kong Karls Land. Two biologists joined the N P summer expe- ditions in 1978 and 1979 to census breeding species in seabird colonies in northeastern Svalbard. T h e results of these registrations are presented in this report. T h e breeding conditions of the following sea- birds a r e described: fulmar Fulrnarus glacialis, kittiwake Rissa tridactyla, little auk Alle alle, Briinnich’s guillemot Uria lomuia, puffin Fra- tercula arctica, and black guillemot Cepphus grylle. T h e breeding occurrence of glaucous gulls Larus hyperboreus and ivory gulls Pagophiln eburnea is also described. Leaders of the ornithological programme were A r e M o b a k in 1978 and Palle Uhd Jepsen in 1979, with assistants Per Magne Jensen and Hdkon Robak, respectively. The authors a r e grateful for their efforts and cooperation through- out the programme. Thanks are also d u e to par- ticipants on other projects for a number of obser- vations which form part of the material for this report. Material and methods The study area T h e investigated seabird colonies are found on localitjes possible t o visit within the limits which had to b e expected, as the foremost aim of the expedition was within topographic and geologic investigations. The different routes taken by the expedition vessel m / s ‘Norvarg’ in 1978 and 1979. and weather conditions made it impossible t o census all the same colonies in 1979 as in 1978. But a large area was covered and seabird colonies not visited before were registered both years. The study areas in 1978 and 1979 are shown in Fig. 1. Observations in 1978 were made mainly in the northwestern part of Nordaustlandet, along the 200 Palle U h d Jepsen & A r e Mobmk 1 G e r e n , Lomfjorden. 28 July Kapp F a n s h a h e and Alkeflellet, 29 July Selanderneset. 31 J u l y Martensoya and Nelsonoya. 4 August Hamiltonbukta, 8 August Depotodden and Goosbukta, 9 August Waldenoya. 11 August Karl XI1 Byane. 12 August F o y n ~ y a and Brochoya, 27 August T h e 1979 rsgistrations included some of the localities visited in 1978 (Tables 1 and 2 ) , but in and localities in the northeastern part of Nord- austlandet T h e following localities for seabird I &-7 addition included K o n g s ~ y a in Kong Karls Land, .UU ..RCS 1t.D \ \ \ I l < \ h l l 1 1 i Fig 1 Map of sur\c\ drea in 1978 and 1979 The large inland localitiea for 1979 \\ere sur\ebed mainl, from a helicopter 0 “ I”. 1 were reg,stered Mosselbukta, 26 July Martensaya. Parryoya, Phippsoya, Nordkapp, west side of Hinlopen. The following seabird col- Depotodden, August and August onies were registered: Nordkapp. 23 July Vesle Tavleaya. 916 Ju1) and W a l d e n ~ y a , 8 August Foynoya and B r o c h ~ y a . 18 August Tuble I . Shematic outline of localities registered L - from the shore. G - from rubber dinghy, E - from the expedition vessel, H - from helicopter. ‘I’ shows that time (number of hours) has not been the Iimiiing factor for accomplishing the counts, and ‘ d indicates that aiailahle time was not sufficient for complete registrations. 1978 l Y i 9 time spent Localities L G E time spent L G E H (hours) h’ORDA U S T L A S D E T Vesle Tavleeya Y Y t Nelsonoya x Y t Nordkapp Y X t X 2 1 Martenseya Y Y t X I t Parryoya x 11 t P h i p p s ~ y a x I t U’aldenclya X X d Y z t t Depotodden X I X 3 t Goosbukta X t Selanderneset X d Zeipelfjellet x X t Karl XI1 O > a n e x I X 3 1 Foynoya Y t x X 4 t Brochoya Y t X Y X 2 t Kapp Bruun x x . I t Damhdugen X d Winsnesbreen X d KO.VGSOYA Kapp Kiihurg Y t Sjogrentiellst \ t Z o r d n c x t x t R c t r i u \ t iellct \ t SPI TSR E R G F \- Xorth oi Rundiscn \ d Gersn Y d Kapp Fanshaac \ d Ilosselhukta Y 2 1 T ab le 2 . L ar ge st n um be r of b re ed in g pa ir s in s ea bi rd c ol on ie s on N or da us tl an de t. K on g K ar ls L an d (K on gs 0y a) . an d N W S pi ts be rg en , re gi st er ed i n 19 78 a nd 1 97 9. T he n um be rs pr ec ed in g pl ac e na m es a re p lo tt ed i n th ei r co rr es po nd in g ge og ra ph ic al p os it io n in F ig . 2. + : br ee di ng . bu t no t co un te d bi rd s. D at e L oc al iti es 19 78 N O R D A U S T L A N D E T 1. N or dk ap p 24 .7 2. V es le T av le ~ y a 26 .7 3. M ar te ns Q ya 4. 8 4. N el so nQ ya 4. 8 5. P ar ry ~ y a 6. P h ip p s~ y a 8. D ep ot od de n 9. 8 9. G oo sb uk ta 9 .8 10 . S el an de rn es et 31 .7 1 1 . Z ei pe lf je ll et 13 . F o y n ~ y a 27 .8 14 . B ro ch oy a 27 .8 IS . K ap p B ru un 16 . D am ha ug en 17 . W in sn es br ee n K O N G S Q Y A 18 . K ap p K ob ur g 19 . S jo gr en fj el le t 20 . N or dn es et 21 . R et zi us fj el le t 22 . N or th o f R un di se n S P IT S B E R G E N 23 . G cr cn 28 .7 24 . K ap p F an sh aw e 29 .7 25 . M os se lb uk ta 7. W al de no ya 11 .8 12 . K ar l X I1 0 y an e 12 .8 B ru nn ic h' s B la ck Fu lm ar K it ti w ak e gu il lc m ot Pu ff in gu il le m ot Iv or y gu ll (F ul m ar us (R u su L it tl e au k ( U ri u (F ra rr rc ir la (C ep ph rr s (P ag op hi la gl nc r a lis ) tr rd ac h la ) ( M e d ie ) lo rn u 1 0 ) ar cr ic a) gr yl le ) eb ur tt eo ) 19 79 19 78 19 79 19 78 19 79 19 78 19 79 19 78 19 79 19 78 19 79 19 78 19 79 19 79 6. 8 6. 8 75 0 54 0 6. 8 6. 8 6. 8 2. 8 14 0 20 0 50 62 0 10 .8 15 0 19 .8 30 17 .8 18 .8 25 21 .8 21 .8 50 9. 8 60 15 00 10 00 26 .7 20 30 0 > 50 12 00 10 0 SO 45 0 15 0 50 > 70 25 0 16 80 25 0 42 0 46 0 12 0 + 60 80 10 40 > 50 12 0 16 00 30 0 50 50 8 50 > 10 60 75 50 70 75 > 36 10 0 > 60 20 60 5 15 + 12 15 + 10 + 65 11 0 85 14 0 10 26 10 15 15 25 10 00 35 202 Pulle U h d Jepsen & A r e M o b e k Karl XI1 (ilyane. 19 August Kapp Bruun. 21 August S . Repaya. 32 August From 13 to 25 August. H . Robak surveyed bird cliffs on Kongssya. Several rather small bird cliffs were found in 1979 in connection with aerial surveys of eider Sonlaterin rnollissinzn and rein- deer Rungifer m r a n d l i s plat\.rhj~nchus. Ice arid observution conditions Quantitative registrations of seabird colonies in Nordaustlandet are hampered by the extreme weather conditions prevailing in the arctic regions. Some colonies could not be counted because of bad weather in 1978 and 1979. In other cases poor visibility and precipitation must be blamed for the inferior quality of a few counts. The count at Waldensya was difficult in 1978. and in 1979 bad weather prevented a visit to Nelsonsya. In 1978. registrations of breeding pairs in sev- eral colonies could be made from a rubber dinghy below the cliffs. but this method could only be used to a limited extent in 1979. when solid bum- mer ice surrounded the islands and coastline i n the northwestern part of Nordaustlandet (Table 1). We therefore had to rely on helicopter trans- port to most localities. Such conditions may t o a high degree influence the biological qualit! of the registrations. and make a comparison of the two years‘ results questionable. In addition. the time difference of the two years’ summer regis- trations at each locality also complicates the pos- sibilities for comparative studies. Census methods Binoculars (7 x 50 or 8 x 40) and telescopes (2Sx) were used for seabird registrations. Tele- scopes could only be used from the deck of the expedition vessel in stable weather. and for regis- trations on land. When registrations were made from the rubber dinghy below the bird cliffs or on land just below the cliffs. binoculars were most useful. Both groups tried to make as exact counts as possible. but because of the large size of some colonies in relation to the registering time avail- able. it was sometimes necessary to make counts in representative parts of the colonies o n l y . and on the basis of these counts to estimate the total number of breeding pairs. Each of the groups made several independent registrations both years, and these were later compared in order to find the most representative total. If the deviation between the results was too great. registrations were made jointly, the observ- ers drawing each other‘s attention to groups of birds or areas that might have been overlooked in the first count. For documentation of the size of the bird col- onies and the distribution of the cliffs, a sketching-in o n Polaroid photos was made in 1978. This method was only used t o a limited extent in 1979. when. on the other hand, drawings were used. In both years some colonies were photographed in black/white for later registration. A t a possible later selection of a representative number of col- onies on Nordaustlandet for more systematic investigations, this method would supply valuable documentation material, especially for species such as kittiwake and Briinnich’s guillemot. I n the field the prime objective was to locate as many seabird colonies as possible and estimate the approximate number of breeding pairs. T h e method of sketching-in colonies, either on Polaroid photos or o n drawn sketches, will make it possible to evaluate the fluctuation pattern of some species, as the space occupied in a given cliff area will change if the populations increase or decrease in number. T h e method appears to give a significant and reliable index, giving future observers a good basis for continuous studies and enabling them to estimate where it is important to concentrate investigations. The sketching-in method might be used with reasonable certainty in size estimates of colonies of h l m a r s , kittiwakes, and Brunnich’s guillemots, but it cannot really b e used for registering little auks. puffins, or black guillemots. breeding more scattered on the cliffs. In 1979 the observers could use the two expe- dition helicopters, and a total of 26 hours were spent o n various biological surveys. This meant that great areas could be surveyed for breeding colonies. Real registrations are not possible and justifiable from aircraft. however, since flying i n the immediate vicinity of colonies causes an unacceptable degree of disturbance. On later occasions it was possible to investigate some of the registered colonies on land. Helicopter was also used to register breeding and moulting eiders. Results Census of seabird colonies 203 Sketches of seabird colonies on Nordallstlandet The positions of the various seabird species on the cliffs are shown in Figs. 3-10. Only localities where it has been possible to sketch in the extent of the colonies are shown. The size of the colonies has been sketched-in on three cliffs both i n 1978 and 1979. For future registrations of the cliffs visited in 1978 and 1979, it is possible with advantage to draw up sketches of some other areas, e.g. Parryoya, Phippsoya, and Waldenoya. There the colonies are found concentrated in well-defined cliff areas. In other areas, however, the birds breed very sparsely, for instance at Foynoya, Brochoya, and in two localities on Kongsoya. In these cases sketches would hardly be of much help. In Figs. 12 and 16 for respectively fulmars and black guillemots, some colonies appear with an arrow. These colonies were registered from helicopter in 1979, but no real count was made. Seabird colonies Four different colonies with more than 1,000 breeding pairs were found on Nordaustlandet during the NP expeditions in 1978 and 1979, on Selanderneset and N e l s o n ~ y a in 1978 and on Martensoya and Kapp Brunn in 1979 (Fig. 2). In three of the colonies, more than 1,000 pairs of one species were breeding. On Nelson0ya, 1,700-1,800 pairs of Brunnich’s guillernot were found and on Martensoya and Kapp Bruun there were approximately 1,200 and 1,000 kittiwake pairs, respectively. One colony of 500-1 .OOO pairs of seabirds was found on Martensoya in 1978, and two on Parryoya and Waldenoya in 1979. In 1978 a colony with possibly more than 100,000 pairs was registered west of Hinlopen on the well-known Alkefjellet mountain. No real count of breeding pairs was made. Two colonies at Geren in Lomfjorden and Kapp Fanshawe on the Lornfjordhalv~lya peninsula were also found to have 1,00&1,500 pairs of kittiwake and 2,000 pairs of kittiwake/Brunnich’s guillemot, respectively. A colony of 1,500 pairs of kittiwake and several smaller colonies on Sjogrenfjellet on Kongscbya, Kong Karls Land, were found in 1979. Breeding pairs in seabird colonies registered in 1978 and 1979 are listed in Table 2. The numerals preceding locality names refer to geo- graphical position (see Fig. 2). Fig. 2 . Seabird colonies recorded and counted in 1978 and 1979. The colonies are shown in three size categories, and include the species mentioned in Table 2. Numbers refer to the list of localities in Table 2 . Fig. 3. Northwest side of Vesle Tavleeya with seabird colonies sketched in. Legend (refers to Figs. >5 and 7-10): ---: col- onies counted in 1978, -: colonies counted in 1979.1. Fulmar Fulmarus glacialis, 2 . Kittiwake Risssa friductyla, 3. Little auk AIle aNe, 4. Briinnich’s guillemot Uria lomuia, 5. Black guil- lemot Cepphus grylle, 6 . mixed colonies of nos. 2 and 4 , 7. mixed colonies of nos. 3 and 5. Vesle Taule@ya (Fig. 3) is an island in the S j u ~ y a n e group and, together with Rossoya, is Svalbard’s northernmost island at almost 81”N. Briinnich’s guillemot is dominant among the breeding birds, and the colony is found at the northwestern corner of the island, opposite R o s s ~ y a . On the west side of the island a few little auks and black guillemots are found breeding, together with the rather small colony of puffins. The colony was counted in 1978. 204 Palle Uhd Jepsen & Are Mobcek - -. - -- Fig. 4. Martensdya observ.ed from the southeast with seabird colonies sketched i n . For legend. see Fig. 3 . Martens@yu (Fig. 4) is the easternmost island in the Sjuciyane group, located a t approximately 80"40'N. The seabird colonies a r e found on the south-southeast side of S d v b e r g e t , where the kittiwake is represented in the largest numbers. Little auks. black guillemots, and puffins breed sparsely. T h e colonies were counted both in 1978 and 1979. N e l s o n @ p ~ (Fig. 5) is o n e of the smallest islands in the Sjuciyane group lying 200-300 metres south- west of Parryejya. T h e island has two rather large seabird colonies containing the largest registered concentrations of breeding Briinnich's guillemots on Nordaustlandet. In addition, a rather large colony of kittiwakes and a rather small population of black guillemots and puffins are found. T h e colonies are found o n the north and northwest sides (Fig. 5B) and o n the south side of the island. O n the sketch (Fig. 5A) showing the south side of the island. the Briinnich's guillemots area is indicated rather inaccurately, because the birds appear extremely concentrated o n clear. vcrtical geological layers in the cliff. O n the west side of K . _-r ,--\ Fig. 5 . Nelsondya observed from the south (A), and the north (B). with seabird colonies sketched in. On the southern cliff Briinnich's guillemots were found scattered over the dashed line. but concentrated around vertical crevices (shaded areas). For legend, see Fig. 3 . the island t h e birds were breeding very sparsely, making it difficult t o sketch-in t h e colonies accu- rately. They have therefore been left out. T h e colonies were counted in 1978. Depotodden (Figs. 6 and 7) is situated in the western part of Laponiahalvoya (approximately 80"ZO'N). T h e seabird colonies a r e found o n the steep cliffs facing south. T h e only colony of ful- mars registered on Nordaustlandet in 1978 was found here, and it also showed t h e highest number of breeding pairs among the few colonies regis- tered in 1979. Both years the colony was found on the cliff north of the cottage. In 1979 a rather small colony of kittiwakes was found on the cliff together with breeding little auks. A small num- ber of black guillemots were observed breeding both in 1978 a n 1979, little auks and black guil- lemots were found scattered o n the cliff, and their breeding areas are therefore difficult t o sketch-in on the map. h g 6 Depotodden. 2 August 1979. Compare with sketch in Fig. 7 Photo: Palle Uhd Jepsen Fig. 7. Depotodden with seabird colonies sketched in. Fulmars were breeding scattered i n the colonies. For legend, see Fig. 3. See also Fig. 6. Selanderneset (Fig. 8) is the name of the north- western corner of Scaniahalv0ya at the mouth of Wahlenbergfjorden (approximately 79"35'N). The seabird colonies are found southwest of the foreland opposite Hinlopen. Colonies of Briinnich's guillemots and kittiwakes were found in 1978 totalling more than 1,000 pairs. A few black guillemots were also registered. T h e local- ities were not visited in 1979. Karl XI1 Oyane (Fig. 9) a r e two islands north of eastern Nordaustlandet at approximately 80"35'N. They a r e connected by a high beach ridge consisting of stone and very coarse-grained gravel. T h e southern cliff of the northern island has a very lush moss vegetation on the lower eroded slope. A colony of kittiwakes was regis- tered there both in 1978 and 1979 totalling 30 and 120 pairs, respectively. Both the southern and northern islands have populations of black guil- lemots. T h e little auk breeds o n the northern island and at least two pairs were registered in 1979. Selanderneset 1978 Fig. 9. Karl XI1 (dyane seen from the southeast with seabird colonies sketched in. For legend, see Flg. 3. Kapp Bruun (Fig. 10) is the northernmost cliff massif o n a peninsula in the northeastern part of Nordaustlandet, east of Prins Oscars Land. The seabird colonies a r e found on a steep cliff at approximately 80"16'N. In 1979 more than 1,000 pairs of kittiwakes were found breeding in four small colonies, and a well-defined colony of about 60 pairs of black guillemots. In addition, approx- imately 80 pairs of black guillemots were breeding scattered o n the cliff. The little auk was breeding in small numbers. The seabirds The following is a description of the breeding occurrence of seabirds in the areas investigated in 1978 and 1979. The survey is hardly satisfac- tory, however, as there are probably still some unknown colonies. In 1979 large areas in the northern and western parts of Nordaustlandet (Fig. 1) were surveyed by helicopter in connection with other registrations, without discovery of any big seabird colonies (see Table 1). Kapp B r u u n 1979 Fig. 8. Southwest side of Selanderneset with seabird colonies sketched in. For legend, see Fig. 3. Fig. ZO. North side of Kapp Bruun with seabird colonies sketched in. For legend. see Fig. 3. 206 Palle Uhd Jepsen & Are Mobmk found in the seabird colonies o n Kong Karls Land and Spitsbergen, marked in Fig. 2. I Ll1"l'irLi. ylrcldll. 1 I n l Fig. 11. Colonies of fulmars shown as the greatest number of breeding pairs counted in 1978 and 1979. The colony marked with arrows was surveyed from helicopter in 1979 and IS not included in Table 2 . Fulniar Fulmarus glacialis (Fig. 11). - The great- est colony on Nordaustlandet was registered on Depotodden, where the number of breeding pairs was estimated at 140 in 1978 and approximately 200 in 1979. On Zeipelfjellet in Palanderbukta. 100-150 pairs of fulmars were counted in 1979 (0. Lauritzen pers. comm.). The most remarkable discoveries of breeding fulmar colonies were at Damhaugen and Wins- nesbreen in 1979, with respectively 50 and 60 pairs. The colonies were situated respectively 15 and 12 km from the nearest coast, and were regis- tered from helicopter. Discovery of breeding fulmars at inland local- ities. e . g . on nunataks, is also mentioned by Nor- derhaug et al. (1977). No breeding fulmars were -- Kittiwake Rissa tridactyla (Fig. 12). - The northern-most seabird colony in Svalbard was registered on Martensoya, with the highest num- ber of breeding pairs on Nordaustlandet in 1979, viz. 1,200. I n 1978 the breeding population here totalled 700-750 pairs. Breeding kittiwakes registered on Nelsonoya in 1978 numbered 480-540 and were distributed in three colonies. The largest colony, with 35C- 400 pairs, was discovered on the south side of the island. This locality was not visited in 1979. In addition small colonies were found in Goosbukta and on Depotodden. A colony of more than 600 pairs was found on Selanderneset in 1978. The Kapp Bruun colony is the second largest discovered on Nordaustlandet in 1979 with 1,040 breeding pairs. The colony was counted on 21 August, at which time most of the juvenile birds were close to fledging. Some had already left the cliff, as juvenile birds could be watched from the vessel. A colony of 120 pairs on Karl XI1 Byane visited on 19 August had fledged juvenile birds in the colony. It was also visited in 1978, when about 30 pairs were registered. The total number of breeding pairs registered on Nordaustlandet in 1978 was just under 2,000, and in 1979, 2.400 pairs. I n 1979 more than 2,000 pairs were counted on Kong Karls Land (Kongsoya). distributed in five colonies, the larg- est having 1,600 pairs. Little auk Alle alle (Fig. 13). - Breeding little auks were found i n greater or smaller numbers FIg. 12. Colonies of kittiwakes shown as the greatest number of hreeding pairs rccorded in 1978 and 1979. Fig. 13. Colonies of little auks shown as the greatest number of breeding pairs in 1978 and 1979. Census of seabird colonies 207 NORDAUSTLA N DET SVALBARD o w I r n Fig. 14. Colonies of Briinnich‘s guillemots shown as the greatest number of breeding pairs in 1978 and 1979. in practically all investigated seabird cliffs. In addition, the species bred alone in small numbers at many localities; this was noticed during the helicopter survey in 1979. It is often difficult to estimate the exact number of breeding little auks in colonies. The birds breed scattered, and the nests are often found at the tops of cliffs in the most inaccessible places. The number of breeding pairs in the various colonies are therefore given with certain reservations, and should be regarded as absolute minimum numbers. In 1978, the largest colony of breeding little auks was registered on Nordkapp, 250-300 pairs. Fifty pairs were counted in the same place in 1979, but this small figure is probably due to the fact that there was very little time available for counting that year. The real number must cer- tainly be much higher, judging from the great number of little auks seen flying near the colony. One flight, for instance, had approximately 200 individuals. In 1979 the largest colony of little auks was found on Parryaya, with about 450 breeding pairs. No breeding little auks were dis- covered during the surveys of Kongsaya. Briinnich’s guillemot Uria lomvia (Figs. 14 and 15). - Only a few, but big colonies were found on Nordaustlandet. The highest number of breed- ing pairs was registered on Sjudyane in 1978, where Nelsonaya alone counted three different colonies totalling 1,680 pairs. In addition, 250 pairs were counted in a colony on Vesle Tavlecbya. These two islands were not visited in 1979, when a colony of 100 pairs was found on Depotodden. Approximately 250 pairs were breeding on Fig. 15. Colony of Briinnich’s guillemots on Walden~ya, 6 August 1979. Photo: Palle Uhd Jepsen. Waldenaya in 1978, and more than 400 pairs in 1979. In 1978 a colony of 600 pairs of Briinnich’s guillemots was found on Selanderneset in Wal- denbergfjorden. This area was not visited in 1979. On Spitsbergen a mixed colony of kittiwakes and Briinnich’s guillemots was found in 1978. A total of 2,000 pairs were found on Kapp Fan- shawe. As previously mentioned, the large colony on Alkefjellet (Lavenskiold 1964) was registered too, probably also including a considerable popu- lation of Briinnich’s guillemots. No Briinnich’s guillemots were recorded on K o n g s ~ y a in 1979. A total of 2,640 and over 500 breeding pairs were registered on Nordaustlandet in 1978 and 1979, respectively. The figures cannot be directly compared, however, because parts of Sjuayane were not visited in 1979. The choice of nesting site in relation to the geological structure of the cliff is significant for the Briinnich’s guillemot. This was particularly clearly observed at Selanderneset in 1978, where the nests were always placed on shelves of hori- zontal, sedimentary rocks (Fig. 8). Puffin Fratercula arctica. - This bird breeds very sparsely at Nordaustlandet. The largest total number of pairs was found on Waldencbya in 1979, 208 Palie U h d Jepsen & Are M o b a k Fig. 16. Colonies of black guillemots shown as the greatest number of breeding pairs counted in 1978 and 1979. Colonies marked with arrows were surveyed from helicopter in 1979 and are not included in Table 2. where the breeding population was estimated at minimum 36 pairs. In addition, the species was found scattered in small quantities on other islands, among others on Vesle Tavleoya. The species was not observed on Kongsoya in 1979. Black gicillernot Cepphus grylle (Fig. 16). - This bird only breeds in small colonies o n Nordaust- lander and on Kongsoya. most often together with other species. T h e black guillemot does not always breed in well-defined colonies. but the nests are sometimes seen scattered o n the cliffs. Several small colonies of black guillemots, with no other species breeding in the immediate vicin- ity, were observed during aerial surveys along the coasts around Prins Oscars Land, Glenhalvoya. Fig. 17. Little auks on Karl XI1 Oyane. 19 August 1979. Photo Palle Uhd Jepsen. and Repoyane in 1979. Because of t h e very lim- ited occurrence of breeding black guillemots, the count figures from the two years must be taken as absolute minima. A t Nordaustlandet a little less than 300 pairs were recorded in 1978, a n d 1,100 pairs in 1979. T h e great difference is first and foremost d u e t o higher aerial survey results in 1979. On Kongsoya approximately 40 pairs of black guillemots were recorded in 1979. Glacuoils gull Larus hyperboreus. - This bird breeds scattered o n Nordaustlandet, and also occurs o n K o n g s ~ y a . It is found mainly in the immediate vicinity of other seabird colonies. T h e largest number of pairs recorded within a well- defined area was six pairs in 1979; a total of 40 pairs were counted in connection with seabird colony surveys. Ivory gull Pagophila eburnea. - This bird was not observed breeding o n Nordaustlandet in 1978 and 1979, but o n Kongsoya five rather small colonies totalling more than fifty pairs were recorded in 1979. Eight pulli were caught and ringed. Accord- ing to Lovenskiold (1964) ivory gulls breed on S t o r ~ y a and Kvitoya, but the species was not recorded at these localities in 1978 and 1979. Ahlmann & Malmberg (1931) also mention that t h e ivory gull is a common breeding bird on Kvitoya. T h e species is quite widespread in areas with drifting ice around Nordaustlandet, and in 1978 and 1979 more than t e n individuals were observed several times a day when the expedition vessel passed through ice covered waters. Discussion This report is o n e of several contributions describ- ing t h e bird-life in these arctic regions and, to a limited extent, comparing the population sizes by observing t h e same colonies in two successive years. It has been mentioned that the figures for some species, first of all for the little auk, black guillemot, and puffin, must be regarded as abso- lute minima. as it is difficult t o produce exact figures for birds breeding scattered and in impass- able mountain regions. Undiscovered seabird col- onies probably exist along the coast of Norden- skioldbukta, Rijpfjorden, and Duvefjorden. I n addition, some seabird colonies have probably been overlooked in Wahlenbergfjorden. Census of seabird colonies 209 The rather different recording methods used in 1978 and 1979, mainly because of the greater extention of solid ice in 1979 compared with the year before, may complicate a direct comparison of the numbers of breeding pairs in colonies vis- ited and recorded both years. When counting from a boat below a cliff, the size of the breeding population will often be underestimated. This is especially so in the case of breeding Briinnich’s guillemots and fulmars, where some birds are hidden behind others or are sitting so far in on the shelves. that they escape notice. Counts made from the mountain top on the other hand will be impeded by a poorer general view and will also cause some disturbances in the colonies. But. if plenty of time is available, the method will probably give good information of the number of breeding pairs present. The two methods may profitably be combined, if circum- stances permit. Norderhaug (1974) points to the possibility of recording nonbreeding individuals as breeding pairs in the seabird colonies. This risk must absolutely be taken into consideration. Counts after the middle of August, when birds start to leave the colonies (Norderhaug et al. 1977), can also give a wrong impression of popu- lation size. The largest seabird colonies in Svalbard are found in the western part of the archipelago, where the favourable influence of the Gulf Stream on the climate and biological production forms the basis of the. for arctic regions, extremely high density in the breeding seabird populations. Farther east, around Nordaustlandet, the sum- mer sea temperature decreases to under 0°C compared to 2 5 3 ° C west of Spitsbergen (L0venskiold 1964). This must to a high degree influence the ecological conditions for the birds, and be one of the reasons for the relatively lower number of breeding pairs here. Great annual variations in the distribution of solid ice around Nordaustlandet must also influence breeding suc- cess and thus cause great, annual fluctuations in the number of breeding pairs in the colonies. TO get more information on these questions, it is important that the counts started be supple- mented with breeding biology studies, including production analyses, mortality studies, and inves- tigations of the food supply available. The development of new methods for estimat- ing breeding populations more exactly should be encouraged. With this end in view, small seabird cliffs with less than 1,000 pairs can be chosen, which may be counted with reasonably great accuracy. Counts should be made several times during 24-hour periods over a fairly lengthy period of time to ascertain day and night varia- tions caused by the activity pattern of the birds, the weather, temperature, etc. (Norderhzug 1980). The accuracy of counts is reduced the larger the size and the higher the density of colonies; selected colonies must therefore be frequently photographed in order to provide reference material and documentation. References Ahlmann. H. W. & Malmberg, S . 1931: S o f n f n a r l i d Polliaoer. Stockholm. 301 pp. Larsen. T. 1965: Ornitologiske unders~kelser fra den nord- vestre del av Vestspitsbergen sornmeren 1967. Norsk Polar- inst. A r b o k 1963. 25P263. L~venskiold, H. L. 1964: Avifauna Svalbardensis. N o r s k Polar- insr. Skrifter N o . 1 2 9 , 460 pp. Norderhaug, M . 1967: Trekkforhold, stredstrohet og pardan- nelse hos alkekonge p l Svalbard. Fauna 20(4). 236244. Norderhaug, M . 1974: Studier av sj0fuglkoloniene p i Fugle- huken, Prins Karls Forland Nasjonalpark. N o r s k Polarmst. A r b o k 1972. 9F106. Norderhaug, M . , Brun. G . & Mollen, G . U. 1977: Barentshav- ets sj0fuglressurser. N o r s k Polarinst. M e d d . N o . 104, 119 pp. Norderhaug, M . 1980: Breeding biology of the Little Auk (Plautus a l l e ) in Svalbard. Norsk P d a r i n s r . Skrtfrer No. 173. 45 pp.