Bird stomach contents analysis - final report: Goosander and Cormorant diet on four Scottish rivers 2019 to 2020

This study analysed the stomach contents of goosanders and cormorants collected from the Rivers Tweed, Dee, Nith and Spey during 2019 and 2020 in order to to assess whether there was evidence of substantial changes in the diets of these species of fish-eating birds since the 1990s.

8. References

Arnold, T.B., & Emerson, J.W. (2011). Nonparametric goodness-of-fit tests for discrete null distributions. The R Journal 3/2, 34-39.

Britton, J.R. & Shepherd, J.S. (2005) Biometric data to facilitate the diet reconstruction of piscivorous fauna. Folia Zool. 54(1–2): 193–200.

Carss, D.N. (in press) There must be some kind of way out of here: towards "reframing" European Cormorant-fisheries conflicts. Ardea 109(3) doi:10.5253/arde.v109i2.a31

Carss, D.N. (ed.) (2003) Reducing the conflict between Cormorants and fisheries on a pan- European scale REDCAFE: Pan European Overview. Final Report to European Commission, (August 2003), pp169. Also available at:

Carss, D. N., Bevan, R. M., Bonetti, A., Cherubini, G., Davies, J., Doherty, D., EL Hili, A., Feltham, M. J., Grade, N., Granadeiro, J. P., Grémillet, D., Gromadska, J., Harari, Y. N. R. A., Holden, T., Keller, T., Lariccia, G., Mantovani, R., McCarthy, T. K., Mellin, M., Menke, T., Mirowska-Ibron, I., Müller, W., Musil, P., Nazirides, T., Suter, W., Trauttmansdorff, J., Volponi, S., & Wilson, B. (1997) Techniques for assessing Cormorant diet and food intake: towards a consensus view. Suppl. Ric. Biol. Selvaggina 26: 197-230.

Carss, D.N. & Brockie, K. (1994) Prey remains at osprey nests in Tayside and Grampian, 1987- 1993. Scott. Birds 17: 132-145.

Carss, D.N. & Ekins, G.R. (2002) Further European integration: mixed sub-species colonies of great Cormorants Phalacrocorax carbo in Britain – colony establishment, diet, and implications for fisheries management. Ardea 90(1): 23-41.

Carss, D.N., Kruuk, H. & Conroy, J.W.H. (1990) Predation on adult Atlantic Salmon, Salmo salar L., by otters, Lutra lutra (L.), within the River Dee system, Aberdeenshire, Scotland. J. Fish Biol. 37: 935-944.

Carss, D.N., van Eerden, M., Enstipp, M., Govedic, M., Gwiazda, R. & Trauttmansdorff, J. (2012) Cormorant diet, food and energy intake. In: Carss, D.N., Parz-Gollner, R. & Trauttmansdorff, J. (2012) The INTERCAFE Field Manual: research methods for Cormorants, fishes, and the interactions between them. pp37-46.

Carss, D.N., Parz-Gollner, R. & Trauttmansdorff, J. (2012) The INTERCAFE Field Manual: research methods for Cormorants, fishes, and the interactions between them. INTERCAFE COST Action 635 Final Report II. NERC/Centre for Ecology & Hydrology on behalf of COST, pp142.

Correia, M.J., Costa, J.L., Antunes, C., De Leo, G. & Domingos, I. (2018) The decline in recruitment of the European Eel: new insights from a 40-year-long time-series in the Minho estuary (Portugal). ICES Journal of Marine Science (2018), 75(6), 1975–1983. doi:10.1093/icesjms/ fsy073

Cramp, S. & Simmons, K.E.L. (1977) Handbook of the Birds of Europe the Middle East and North Africa. The Birds of the Western Palearctic. Volume I Ostrich to Ducks. Oxford University Press, Oxford.

Dimitrova, D.S., Kaishev, V.K. and Tan, S. (2020). Computing the Kolmogorov-Smirnov distribution when the underlying CDF is purely discrete, mixed, or continuous. Journal of Statistical Software. 95/10, 1–42.

Feltham, M.J. (1990) The diet of red-breasted mergansers (Mergus serrator) during the smolt run in N.E. Scotland: the importance of Salmon (Salmo salar) smolts and parr. J. Zool., Lond. 222 285- 292.

Gulland, J.A. & Rosenberg, A.A. (1992) A review of length-based approaches to assessing fish stocks. FAO Fisheries Technical Paper. No. 323. Rome, FAO. 1992. 100p.

Hájková, P., Roche, K. & Kocain, U. (2003) On the use of diagnostic bones of brown Trout, Salmo trutta m. fario, Grayling, Thymallus thymallus and Carpathian sculpin, Cottus poecilopus in Eurasian otter, Lutra lutra diet analysis. Folia Zool. 52(4): 389–398.

Hindar, K, Hutchings, J.A., Diserud, O. & Fiske, P. (2011) Stock, Recruitment and Exploitation. In: Aas, O, Einum, S., Klenentsen, A., and Skurdal, J. (eds) Atlantic Salmon Ecology, pp299-331, Blackwell Publishing.

Letcher, B.H. & Gries, G. (2003) Effects of life-history variation on size and growth in stream- dwelling Atlantic salmon. Journal of Fish Biology 62: 97-114.

Marquiss M. & Carss, D.N. (1997) Methods of estimating the diet of sawbill ducks Mergus spp. and Cormorants Phalacrocorax carbo. Supplemento Ricerche di Biologia della Selvaggina 26: 247-258.

Marquiss, M. & Carss, D.N. (1994) Avian piscivores: basis for policy. National Rivers Authority, Bristol, pp106.

Marquiss, M., Carss, D.N., Armstrong, J.D., & Gardiner, R. (1998) Fish-eating birds and Salmonids in Scotland. Report on fish-eating birds research (1990-97) to the Scottish Office Agriculture, Environment and Fisheries Department, 156pp. Stationary Office, Edinburgh. Also available at:

McCormick, S.D., Hansen, L.P., Quinn, T.P. & Saunders, R.L. (1998) Movement, migration, and smolting of Atlantic salmon (Salmo salar). Canadian Journal of Fisheries & Aquatic Sciences 55: 77-92.

Morgan, R.I.G., Greenstreet, S.P.R. & Thorpe, J.E. (1986) First observations on distribution, food and fish predators of postsmolt Atlantic salmon, Salmo salar, in the outer Firth of Clyde. ICES CM 1986/M: 27, 8pp.

Russell, I.C., Dare, P.J., Eaton, D.R. & Armstrong, J.D. (1996) Assessment of the problem of fish-eating birds in inland fisheries in England and Wales. Lowestoft: Directorate of Fisheries Research.

SalmonBusiness 2018

Siegel, S. & Castellan, N.J. (1988) Nonparametric Statistics for the Behavioural Sciences. 2nd Edition, McGraw-Hill, New York.

Spencer, R. (1983) The Ringers' Manual. Third Edition, British Trust for Ornithology, Tring, Herts.

Thorpe, J.E., Talbot, C. & Villarreal, C. (1982) Bimodality of growth and smolting in Atlantic salmon, Salmo salar L. Aquaculture 28: 123-132.

Thorstad, E.B., Whoriskey, F., Rikardsen, A. & Aarestrup, K. (2011) Aquatic nomads: the life and migrations of the Atlantic Salmon. In: Aas, O, Einum, S., Klenentsen, A., and Skurdal, J. (eds) Atlantic Salmon Ecology, pp1-32, Blackwell Publishing.

Todd, C.D., Friedland, K.D., MacLean, J.C. Hazon, N. & Jensen, A.J. (2011) Getting into hot water? Atlantic Salmon responses to climate change in freshwater and marine environments. In: Aas, O, Einum, S., Klenentsen, A., and Skurdal, J. (eds) Atlantic Salmon Ecology, pp409-443, Blackwell Publishing.

van Eerden, M.R., van Rijn, S., Volponi, S., Paquet, J-Y. & Carss, D.N. (2012) Cormorants and the European environment: exploring Cormorant status and distribution on a continental scale. INTERCAFE COST Action 635 Final Report I. NERC/Centre for Ecology & Hydrology on behalf of COST, pp126.

Ward, D.M. & Hvidsten, N.A. (2011) Predation: compensation and context dependence. In: Aas, O, Einum, S., Klenentsen, A., and Skurdal, J. (eds) Atlantic Salmon Ecology, pp199-220, Blackwell Publishing.

Wires, L.R., Carss, D.N., Cuthbert, F.J. & Hatch, J.J. (2003) Transcontinental connections in relation to Cormorant-fisheries conflicts: perceptions and realities of a "bête noire" (black beast) on both sides of the Atlantic. Vogelwelt 124, Suppl.: 389-400.



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