Department: Comparative Biomedical Sciences

Campus: Hawkshead

Research Centres: Structure & Motion Laboratory

I am currently a postdoctoral researcher on the CARDyAL project (funded by EPSRC) investigating flocking behaviour in birds. In particular, the potential aerodynamic benefits of 'Vee' flight formation in migrating birds such as geese and ibis. See my website for more information about my research, and for a copy of my PhD thesis, click the link.



  • (2004-2008) BBSRC funded PhD: School of Biosciences, University of Birmingham, Edgbaston, Birmingham, UK, B15 2TT. "Echophysiological aspects of the annual cycle of Barnacle Geese (Branta leucopsis)". Fieldwork in Svalbard. Supervised by Prof. Pat Butler and Dr. Jon Green. Examined by Profs Graham Martin and Theunis Piersma.
  • (2003-2004) ESF funded MSc in Ecology: School of Biological Sciences, University of Wales (Bangor), Bangor, Wales, UK, LL57 2UW.
  • (1998-2001) BSc (Hons.): University of Wales (Aberystwyth), Aberystwyth, Wales, UK, SY23 3DA. 2i class in Freshwater and Marine Biology with Ecology and Zoology. Including fieldwork in Tenerife.


  • (2011-2014) EPSRC Postdoctoral Researcher: Structure and Motion Laboratory, Royal Veterinary College, Hawkshead Lane, Hatfield, Herts, AL9 7TA. CARDyAL project on aerodynamics in flocking birds, with Prof Alan Wilson and Dr. Jim Usherwood.
  • (2008-2011) Leverhulme/HFSP Postdoctoral Researcher: School of Biosciences, University of Birmingham, Edgbaston, Birmingham, UK, B15 2TT. Investigating the structure and physiology of eggshells, with Dr. Phill Cassey, Prof. Tim Blackburn and the Natural History Museum.
  • (2002-2003) RSPB. Research Assistant on the Shetland Islands, with Dr. Norman Ratcliffe.

Honorary and Visiting Positions

  • (2011-) Honorary Research Fellow, Centre for Ornithology, School of Biosciences, University of Birmingham, Edgbaston, Birmingham, UK, B15 2TT.
  • (2011) Visiting Scientist. School of Biological Sciences, University of Queensland, Adelaide, Australia (with Dr. Craig White).

 Grants and Awards

  • £970 Awarded by the Company of Biologists to attend Society for Experimental Biology Annual Meetings in Canterbury (2006), Glasgow (2009) and Prague (2010).
  • £1100 Awarded from the Head of School travel fund to undertake lab visits (Aberdeen), present a seminar (Denmark), and complete Module 5 of the Home Office License Course, which enables me to be a UK project licence holder.
  • £5700 BBSRC, awarded in 2006 to undertake fieldwork in Svalbard.
  • £12,500 NERC, for the study of isotopic techniques to assess body condition in animals.


My research is located at the interface of the physiology, sensory ecology and behaviour of vertebrates, and more specifically, birds. The common theme of my work focuses on how animals adapt their behaviour and ecology to the challenges of their environment, within the constraints of their own physiological and anatomical limitations. Such questions are particularly important in the light of global environmental change and exploitation of natural resources. My main aim is to investigate the behaviour, sensory ecology and physiology of animals by their allocations of energy to different behaviours. I believe that a detailed understanding of the energetic costs of behaviours is vital to understanding physiological mechanisms and ecological processes thoroughly. Such quantification will enable fundamental questions to be answered about adaptations and plasticity to environments that are changing temporarily or permanently.

My PhD in avian physiology focused on the annual cycle of energy expenditure in birds, using barnacle geese as a model. Using a combination of techniques, including the deployment of heart rate data loggers, it has been possible to record and measure the energetic cost of specific events within the annual cycle in both captive and wild barnacle geese, such as breeding, migration and moult. Of particular interest were the dramatic changes in body mass, metabolic rate and behaviour observed in the captive geese during their annual wing moult, with birds undergoing a 25% reduction in body mass during the flightless phase, accompanied by an 80% increase in resting metabolic rate.

 See my website for more information about my research.


Portugal, S.J., Hubel, T.Y., Fritz, J., Heese S., Trobe, D., Voelkl, B., Hailes, S., Wilson, A.M. and Usherwood, J.R. (2014) Upwash exploitation and downwash avoidance by flap phasing in ibis formation flight. Nature. 505: 399-402.

Portugal, S.J. and Pierce, S. E. (2014) Who's looking at your data? Science In Press.

Portugal, S.J., Hauber M. E., Maurer, G., Stokke, B. G., Grim, T. and Cassey, P. (2014) Early hatching of an avian brood parasites embryo cannot be explained by enhanced gaseous exchange across the eggshell.  Journal of Zoology. In Press. 

Brulez, K., Choudhary, P. K., Maurer, G., Portugal, S. J., Boulton, R. L., Webber, S. L. and Cassey, P. (2014) A note on the repeatability of visually scoring eggshell patterns, Journal of Ornithology. In Press.

White, C.R., Cassey, P., Schimpf, N., Halsey, L. G., Green, J. A. and Portgual, S. J. (2013) Implantation reduces the negative effects of bio-logging devices on birds. Journal of Experimental Biology. 216: 537-542.

Alton, L. A., Portugal, S. J. and White, C. R. (2013) Balancing the Competing Requirements of Air-breathing and Display Behaviour During Male-Male Interactions in Siamese Fighting Fish, Betta splendens. Comparative and Biochemical Physiology. 164: 363-367. 

Portugal, S. J., Green, J.A., White, C. R., Guillemette, M. and Butler, P. J. (2013) Wild geese do not increase flight behaviour prior to migration. Biology Letters. 8: 469-472.

Guillemette, M., Richman, S., Portugal, S. J, and Butler, P. J. (2012) Behavioural compensation in relation to metabolic demands facilitates migration hyperphagia in a large bird. Functional Ecology. 25: 876-883.

Cassey, P., Thomas, G., Portugal, S. J., Maurer, G., Hauber, M., Grim, T., Lovell, G. and Miksik, I. (2012) Why are birds' eggs colourful? Eggshell pigments co-vary with life-history and nesting ecology among British breeding non-passerine birds. Biological Journal of the Linnean Society. 106: 657-672.

Martin, G. R., Portugal, S. J. and Murn, C. (2012) Perceptual basis of vulture vulnerability to collisions. Ibis. 154: 626-631.

Cassey, P., Miksik, I., Portugal, S. J., Maurer, G., Ewen, J. G., Zarate, E., Sewell, M. A., Karadas, F., Grim, T. and Hauber, M. (2012) Avian eggshell pigments are not consistently correlated with colour measurements or egg constituents in two Turdus thrushes. Journal of Avian Biology. In Press.

Maurer, G., Portugal, S. J. and Cassey, P. (2012) As assessment of measurements and indices of eggshell thickness and its variation with egg region and shape in European birds. Ibis. 154: 714-724.

Portugal, S. J., Green, J. A., Piersma, T., Eichhorn, G. and Butler, P. J. (2011) Greater energy stores enable flightless moulting geese to increase resting behaviour. Ibis. 153: 868-874.

Maurer, G., Portugal, S. J. and Cassey, P. (2011) An inside view of eggshell pigmentation. Journal of Avian Biology. 42: 494-504.

Martin, G. R. and Portugal, S. J. (2011) Differences in foraging ecology drive variation in visual field topography in ibises and spoonbills (Threskiornithidae). Ibis. 153: 662-671.

Portugal, S. J. and Guillemette, M. G. (2011) The use of body mass loss to estimate metabolic rate in birds. Comparative and Biochemical Physiology A. 158: 329-336.

Portugal, S. J., Butler, P. J., Green, J. A. and Cassey, P. (2011) Indications of phenotypic plasticity in moulting birds: captive geese reveal adaptive changes in mineralisation of their long bones during wing moult. Journal of Ornithology. 152: 1055-1061.

Maurer, G., Portugal, S. J. and Cassey, P. (2011) Cryptic patterning reveals separate mechanical and gas conductance functions of bird egg speckles. Journal of Zoology. 285: 194-204.

Portugal, S. J. and Guillemain, M. Vigilance (2011) Vigilance patterns of wintering Eurasian wigeon: female benefits from male low-cost behaviour. Journal of Ornithology. 152: 661-668.

Maurer, G., Portugal, S. J., Boomer, I and Cassey, P. (2011). Avian embryonic development does not change the stable isotope composition of the calcite eggshell. Reproduction, Fertility and Development. 23: 339-345.

Portugal, S. J., Cooper, H. J., Zamprione, C. D., Wallace, L. L. and Cassey, P. (2010) Can museum egg specimens be used for proteomic analyses? Proteome Science. 8: 40

Portugal, S. J., Maurer, G. and Cassey, P. (2010) Eggshell permeability: A standard technique for determining inter-specific rates of water vapour conductance. Physiological and Biochemical Zoology. 83: 1023-1031.  

Portugal, S. J., Quinton, K., Isaac, R. and Reynolds, S. J. (2010) Do captive waterfowl respond to the flightless period of wing moult in the same manner as their wild counterparts? Journal of Ornithology. 151: 443-448.

Cassey, P., Portugal, S. J., Maurer, G., Boulton, R., Hauber, M., Ewen, J. and Blackburn, T. M. (2010) A comparative study of the evolutionary variability in eggshell colour of birds. PLoS One. 5: e12054

Halsey, L. G., Portugal, S. J., Smith, J. A., Murn, C. A. and Wilson, R. P. (2009) Recording raptor behaviour on the wing via accelerometry. Journal of Field Ornithology. 80: 171-177.

Portugal, S. J., Thorpe, S. K. S., Green, J. A., Myatt, J. P. and Butler, P. J. (2009) Testing the use/disuse hypothesis: pectoral and leg muscle changes in captive barnacle geese during wing moult. Journal of Experimental Biology. 212: 2403-2410.

Portugal, S. J., Green, J. A., Cassey, P., Frappell, P. B. and Butler, P. J. (2009) Predicting the rate of oxygen consumption from heart rate in barnacle geese: effects of captivity and annual changes in body condition. Journal of Experimental Biology. 212: 2941-2948. 

Portugal, S. J. Ecophysiological aspects of the annual cycle of the Barnacle Goose, Branta leucopsis. PhD thesis, University of Birmingham. Link to thesis can be found here.

Portugal, S. J., Green, J. A. and Butler, P. J. (2007) Annual changes in body mass and resting metabolism in captive barnacle geese: the importance of wing moult. Journal of Experimental Biology. 210: 1391-1397.

White, C. R., Portugal, S. J., Martin, G. R. and Butler, P. J. (2006) Respirometry: Anyhdrous Drierite equilibrates with carbon dioxide and increases washout times. Physiological and Biochemical Zoology. 79: 977-980.

I regulary supervise a variety of Undergraduate and Postgraduate student projects.

Top of page