Diet of adult and immature North Norwegian Black Guillemots Cepphus grylle

Barrett, R.T.1, Christensen-Dalsgaard, S.2,3*, Anker-Nilssen, T.2 & Fangel, K4

1 Department of Natural Sciences, Tromsø University Museum, PO Box 6050 Langnes, NO-9037 Tromsø, Norway;

2 Norwegian Institute for Nature Research, PO Box 5685 Sluppen, NO-7485 Trondheim, Norway;

3 Department of Biology, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway;

4 Norwegian Institute for Nature Research, Fakkelgården, NO-2624 Lillehammer, Norway.

Full paper


In this first study of adult Black Guillemot Cepphus grille diet in the Norwegian mainland, 62 of 63 birds caught incidentally in Lumpfish Cyclopterus lumpus gill nets in the north of the country in April-June 2012 and 2013 contained food remains in their stomachs. Fourteen prey taxa were identified and crustaceans were present in 90% of the stomachs containing food, with squat lobsters (sub-order Anamura) being most common (in 79%). Rock Gunnel Pholis gunnellus was present in 17 (27%) of the samples. The only other prey types to be found in more than 20% of the samples were sculpins (Cottoidei, probably Cottidae and Agonidae, in 13 samples = 21%) and remains of Caridean shrimps (also in 13 samples). There were no differences in the frequencies of taxa in the diets of immature and adult birds or of males and females.


Seabirds are integral components of marine ecosystems and good indicators of changes in the marine environment (e.g. Furness & Monaghan 1987, Furness & Camphuysen 1997). For example, seabird data, including diet, give early indications of fluctuations in fish stocks and oceanographic conditions (Montevecchi 1993, Frederiksen et al. 2004). Conventional studies of seabird diet are often carried out during the breeding season when birds are at the nest and easiest to sample in a non-destructive manner. As a result, overall documentation of food preferences for a given species tend to be biased in space and time, often with a paucity of data from outside the breeding season when birds are not restricted to feeding close to the nest site. Samples collected during the breeding season may consist of prey remains in stomachs of birds collected at sea, food brought to chicks or undigested remains in pellets or faeces. Collecting birds at sea is, of course, possible at any time of year but most practical when birds are concentrated in predictable areas such as on or near the breeding site. Due to ethical considerations and the fact that the method rarely achieves a representative picture of the spatial and temporal variation in diet, the direct killing of birds as a sampling tool for diet studies alone is, however, discouraged (Barrett et al. 2007). Alternative sources such as birds accidentally killed in fisheries, oil spills or wrecks are, instead, preferred. Biochemical methods such as stable isotope or fatty acid analyses have allowed us to explore further adult diets non-destructively. They have certain advantages, such as integrating diet composition over space and time, and new methods such as the use of environmental DNA (eDNA) are constantly under development. These must, however, be considered as important supplements to, rather than replacements of, traditional studies of ingested prey (Bearhop et al. 2001, Karnovsky et al. 2012).

Of the millions of auks (Alcidae) that breed in the North Atlantic, the Black Guillemot (or Tystie, Cepphus grille) is among the least studied, probably because of its habit of breeding widely dispersed along coastlines at sheltered, often very difficult to access nest sites. In addition, their distribution is biased towards the (high) Arctic (Gaston & Jones 1998). As a result, diet studies are scarce. In the Arctic, they feed both inshore and offshore, among ice floes and along the ice edge where they forage both on the sea bottom down to ca. 30 m or dive under the ice to catch ice-associated (sympagic) crustaceans and fish (e.g. Mehlum & Gabrielsen 1993, Divoky et al. 2015). In sub-arctic and boreal regions, Black Guillemots feed on a wide variety of fish and invertebrates caught in the water column and on the seafloor. They usually forage within a few kilometres of the coast, often around rocky islands and over submerged reefs in sheltered waters with strong tidal currents and frequently among kelp (Laminariales) (Gaston & Jones 1998).

In Norway about 5,000 pairs of Black Guillemot breed on Svalbard and about 35,000 pairs on the mainland, nearly all north of the Stad Peninsula (62⁰ 11.7’N, 5⁰ 5.9’E), i.e. along the coasts of the Norwegian and Barents Seas. The Norwegian population constitutes 9‒13% of the North Atlantic (and hence nearly the World) population of 260,000‒410,000 pairs (Mitchell et al. 2004, Barrett et al. 2006, Fauchald et al. 2015a). Because of an evident decline in numbers, the species is ‘red listed’ as Vulnerable on the Norwegian mainland (Barrett et al. 2006, Kålås et al. 2015).

While predation by feral American Mink Neovison vison has been a significant cause of the Black Guillemot population decline in Norway, drowning in fishing nets, especially those set for Lumpfish Cyclopterus lumpus is possibly an important contributor, especially in the north of the country (Barrett & Anker-Nilssen 1997, Fangel et al. 2015). A reversal of the population decline requires effective management based on knowledge of extrinsic and intrinsic factors that affect Black Guillemot population dynamics, including improved knowledge of diet preferences (Fauchald et al. 2015b). Few studies, however, have addressed the diet of Black Guillemots in Norwegian waters. Chick diet has been documented in three colonies on the mainland (Larsen et al. 1989, Larsen & Sæter 1989, Larsen 1990, Barrett & Anker-Nilssen 1997, Anker-Nilssen 2010) and three studies have documented summer diet of adults on Svalbard (Hartley & Fisher 1936, Lønne & Gabrielsen 1992, Mehlum & Gabrielsen 1993). This study is the first to address the diet of adult Black Guillemots on the Norwegian coast.


The Black Guillemots used in this study were collected during a study of the bycatch of seabirds in Norwegian coastal commercial fisheries, funded by the Norwegian Environment Agency. We are grateful to the fishermen who participated in the data-collection and to the contact-persons responsible for forwarding the frozen birds to us. We also thank Prof. Torstein Pedersen, University of Tromsø for sharing his insight into squat lobster distribution with us.


Anker-Nilssen, T. 2010. Key‐site monitoring in Røst in 2009. SEAPOP Short Report 12‐2010 (available at

Anthony, J.A., Roby, D.D. & Turco, K.R. 2000. Lipid content and energy density of forage fishes from the northern Gulf of Alaska. Journal of Experimental Marine Biology and Ecology 248: 53‒78.

Asbirk, S. 1979. The adaptive significance of the reproductive pattern in the black guillemot, Cepphus grille. Videnskabelige meddelelser fra den Naturhistoriske forening i Kjöbenhavn 141: 29‒80.

Barrett, R.T. & Anker-Nilssen, T. 1997. Egg-laying, chick growth and food of Black Guillemots Cepphus grille in North Norway. Fauna norvegica, Serie C, Cinclus 20: 69‒79.

Barrett, R.T., Camphuysen, C.J., Anker-Nilssen, T., Chardine, J.W., Furness, R.W., Garthe, S., Hüppop, O., Leopold, M. F., Montevecchi, W.A., & Veit, R.R. 2007. Diet studies of seabirds: a review and recommendations. ICES Journal of Marine Science 64: 1675‒1691.

Barrett, R.T., Fieler, R., Anker‐Nilssen, T. & Rikardsen, F. 1985. Measurements and weight changes of Norwegian adult Puffins Fratercula arctica and Kittiwakes Rissa tridactyla during the breeding season. Ringing & Migration 6: 102‒112.

Barrett R.T., Lorentsen, S.-H. & Anker-Nilssen, T. 2006. The status of breeding seabirds in mainland Norway. Atlantic Seabirds 8: 97‒126.

Bearhop, S., Thompson, D. R., Phillips, R. A., Waldron, S., Hamer, K. C., Gray, C. M., Votier, S. C., Ross, B.P. & Furness, R.W. 2001. Annual variation in great skua diets: the importance of commercial fisheries and predation on seabirds revealed by combining dietary analyses. Condor 103: 802–809.

Belopol’skii, L.O. 1961. Ecology of Sea Colony Birds of the Barents Sea. Academy of Sciences, USSR. Israel Programme for Scientific Translations, Jerusalem.

Breiby, A. 1985. Otolitter fra saltvannsfisker i Nord-Norge. Tromura 45, Tromsø Museum, Univ. of Tromsø.

Cairns, D.K. 1981. Breeding, Feeding, and Chick Growth of the Black Guillemot (Cepphus grille) in Southern Quebec. Canadian Field-Naturalist 95: 312‒318.

Cairns, D.K. 1987. Diet and foraging ecology of Black Guillemots in northeastern Hudson Bay. Canadian Journal of Zoology 65: 1257‒1263.

Camphuysen, C.J. 2007. Standard autopsy: post-mortem examinations of stranded seabirds. Technical documents 4.1, Handbook on Oil Impact Assessment, version 1.0. Online edition: (version 1.2 at

Camphuysen C.J. & van Franeker, J.A. 2007. Ageing and sexing manual for stranded seabirds. Technical documents 4.1, Handbook on Oil Impact Assessment, version 1.0. Online edition, (version 1.2 at

Company, J.B. & Sardà, F. 1998. Metabolic rates and energy content of deep-sea benthic decapod crustaceans in the western Mediterranean Sea. Deep-Sea Research I 45: 1861‒1880.

Dam, M. 1998. Hvad spiser tejst, edderfugl og topskarv på Færøerne, og hvad er inholdet af miljøgifte i disse fugle? Heisufrøđiligia Starvsstovan Report 1998:2, Tórshavn.

De Cáceres, M., Sol, D., Lapiedra, O. & Legendre, P. 2011. A framework for estimating niche metrics using the resemblance between qualitative resources. Oikos 120: 1341‒1350

De Grave, S. & Turner, J.R. 1997. Activity rhythms of the squat lobsters, Galathea squamifera and G. strigosa (Crustacea: Decapoda: Anumura) in south-west Ireland. Journal of the Marine Biological Association of the UK 77: 273‒276.

Divoky, G.J., Lukacs, P.M. & Druckenmiller, M.L. 2015. Effects of recent decreases in Arctic sea ice on an ice-associated marine bird. Progress in Oceanography 136: 151‒161

Dunn, E.H. 1975. Caloric intake of nestling double-crested cormorants. Auk 92: 553‒565.

Ewins, P.J. 1987. Opportunistic feeding of Black Guillemots Cepphus grille at fishing vessels. Seabird 10: 58‒59.

Ewins, P.J. 1990. The diet of black guillemots Cepphus grylle in Shetland. Holarctic Ecology 13: 90‒97.

Fangel, K., Aas, Ø., Vølstad, J.H., Bærum, K.M., Christensen-Dalsgaard, S., Nedreaas, K., Overvik, M., Wold, L.C. & Anker-Nilssen, T. 2015. Assessing incidental bycatch of seabirds in Norwegian coastal commercial fisheries: Empirical and methodological lessons. Global Ecology & Conservation 4: 127‒136.

Fauchald, P., Anker-Nilssen, T., Barrett, R.T., Bustnes, J.O., Bårdsen, B.-J., Christensen-Dalsgaard, S., Descamps, S., Engen, S., Erikstad, K.E., Hanssen, S.A., Lorentsen, S.-H., Moe, B., Reiertsen, T.K., Strøm, H. & Systad, G.H. 2015a. The status and trends of seabirds breeding in Norway and Svalbard. NINA Report 1151, Trondheim

Fauchald, P., Barrett, R.T., Bustnes, J.O., Erikstad, K.E., Nøttestad, L., Skern-Mauritzen, M. & Vikebø. F. 2015b. Sjøfugl og marine økosystemer. Status for sjøfugl og sjøfuglenes næringsgrunnlag i Norge og på Svalbard. NINA Report 1161, Trondheim.

Frederiksen, M., Wanless, S., Harris, M. P., Rothery, P. & Wilson, N. J. 2004. The role of industrial fisheries and environmental change in the decline of North Sea black-legged kittiwakes. Journal of Applied Ecology 41: 1129-1139.

Furness, R. W. & Camphuysen, C. J. 1997. Seabirds as monitors of the marine environment. ICES Journal of Marine Science 54: 726–737.

Furness, R. W. & Monaghan, P. 1987. Seabird Ecology. Blackie, Glasgow.

Gaston, A.J. & Jones, I.L. 1998. Bird families of the world. The Auks. Oxford University Press, Oxford.

Gibson, R.N. 1969. The biology and behaviour of littoral fish. Oceanography and Marine Biology 7: 367‒410.

Goulet, D., Green, J.M. & Shears, T.H. 1986. Courtship, spawning, and parental care behaviour of the lumpfish Cyclopterus lumpus L., in Newfoundland. Canadian Journal of Zoology 64: 1320‒1325.

Härkönen, T. 1986. Guide to the Otoliths of the Bony Fishes of the Northeast Atlantic. Hellerup, Denmark: Danbiu.

Hartley, C.H. & Fisher, J. 1936. The marine foods of birds in an inland fjord in west Spitsbergen. Part 2. Birds. Journal of Animal Ecology 5: 305‒311.

IBM Corp. 2015. IBM SPSS Statistics for Windows, Version 23.0. Armonk, NY: IBM Corp.

Kålås J.A., Dale, S., Gjershaug, J.O., Husby, M., Lislevand, T., Strann, K.-B. & Strøm, H., 2015. Fugler (Aves). Norsk Rødliste for Arter 2015. Artsdatabanken, Trondheim. (Accessed 11 Jan 2016 at

Karnovsky, N.J., Hobson, K.A. & Iverson, S.J. 2012. From lavage to lipids: estimating diets of seabirds. Marine Ecology Progress Series 451: 263‒284.

Larsen, B.H., Lorentsen, S.-H. & Sæter, S.A. 1989. Hekkebiologi, beiteområder og døgnrytmikk hos teist i en koloni på Halten i Sør-Trøndelag, 1988. Unpublished report, Norwegian Ornithological Society, Klæbu.

Larsen, B.H. & Sæter, S.A. 1989. Næringsøkologi og beiteområder hos teist i kolonien på Halten i Frøya kommune. Resultater fra undersøkelsene i 1989. Unpublished report, Norwegian Ornithological Society, Klæbu.

Larsen, B.H. 1990. Næringsøkologi hos teist på Halten i Frøya kommune. Resultater fra undersøkelsene i 1990. Unpublished report, Norwegian Ornithological Society, Klæbu.

Lønne, O.J. & Gabrielsen, G.W. 1992. Summer diet of seabirds feeding in sea-ice-covered waters near Svalbard. Polar Biology 12: 685‒692.

Mancini, P.L., Bond, A.L., Hobson, K.A., Duarte, L.S. & Bugoni, L. 2013. Foraging segregation in tropical and polar seabirds: Testing the Intersexual Competition Hypothesis. Journal of Experimental Marine Biology & Ecology 449: 186‒193.

McLeay, Page, B., Goldsworthy, S.D., Ward, T.M. & Paton, D.C. 2009. Size matters: variation in the diet of chick and adult crested terns. Marine Biology 156: 1765‒1780.

Mehlum, F. & Gabrielsen, G.W. 1993. The diet of high-Arctic seabirds in coastal and ice-covered, pelagic areas near the Svalbard archipelago. Polar Research 12: 1‒20.

Mitchell, P.I., Newton, S.F., Ratcliffe, N. & Dunn, T.E. 2004. Seabird Populations of Britain and Ireland. Results of the Seabird 2000 Census (1998-2002). T. & A.D. Poyser, London, UK.

Montevecchi, W.A. 1993. Birds as indicators of change in marine prey stocks. In: Furness, R.W. & Greenwood, J.J.J. (eds.). Birds as Monitors of Environmental Change: 219–266. Chapman & Hall, London.

Ólafsdóttir, K. Sv. 2002. Reported decrease of PCB in black guillemot eggs during the period 1999 to 2001. Could a change in black guillemot diet be a contributing factor? NáttúruvísindadeildinRit 2002:13. BSc thesis, Univ. of Faeroe Islands, Tórshavn.

Pallas, A., Garcia-Galvo, B., Corgos, A., Bernardez, C. & Freire, J. 2006. Distribution and habitat use patterns of benthic decapod crustaceans in shallow waters: a comparative approach. Marine Ecology Progress Series 324: 173‒184.

Petersen, A. 1981. Breeding biology and feeding ecology of Black Guillemots. D.Phil. thesis, Univ. Oxford.

Poore, G.C.B., Ahyong, S.T. & Taylor, J. 2011. The Biology of Squat Lobsters. CSIRO Publishing, Collingwood, Australia.

R Development Core Team. 2016. R: A Language and Environment for Statistical Computing. R Foundation for Statistical Computing, Vienna.

Rao, C.R. 1982. Diversity and dissimilarity coefficients: a unified approach. Theoretical Population Biology 21: 24–43

Sawyer, P.J. 1967. Intertidal Life-History of the Rock Gunnel, Pholis gunnellus, in the Western Atlantic. Copeia 1967(1): 55‒61.

Shealer, D.A. 2002. Foraging Behavior and Food of Seabirds. In: Schreiber, E.A. & Burger, J. (eds.) Biology of Marine birds: 137‒177. CRC Press, Boca Raton.

Sivertsen, K. 2006. Overgrazing of kelp beds along the coast of Norway. Journal of Applied Phycology 18: 599‒610.

Soleim, P.A. 1945. A Contribution to the Knowledge of the Lesser Sandeel (99) in North European Waters. Fiskeridirektoratets Skrifter, Serie Havundersøkelser Vol. VIII (1). Fiskeridirektøren, Bergen.

Steimle, F.W. & Terranova, R.J. 1988. Energy contents of northwest Atlantic continental slope organisms. Deep-Sea Research 35: 415‒423.

Van Heezik, Y. M., and Seddon, P. 1989. Stomach sampling in the yellow-eyed penguin: erosion of otoliths and squid beaks. Journal of Field Ornithology 60: 451–458.

Watt, J., Pierce, G.J. & Boyle, P.R., 1997. Guide to the Identification of North Sea Fish Using Premaxillae and Vertebrae. ICES Cooperative Research Report No. 220. Copenhagen, Denmark: International Council for Exploration of the Sea. pp. 1–231.

Wiens, J.A. & Scott, J.M. 1975. Model estimation of energy flow in Oregon coastal seabird populations. Condor 77: 439‒452.

Wilson, L. J., Daunt, F. & Wanless, S. 2004. Self-feeding and chick-provisioning diet differ in the Common Guillemot Uria aalge. Ardea 92: 197‒208.