Reproducing in a changing environment

Organisms need to fine tune their reproductive decisions with the environment in which they live in order to reproduce successfully. In a time where many aspects of our environment are changing it is important to have a good understanding how organisms can deal with these changes. I am particularly interested in the early stages of the reproductive cycle of birds. This life history stage can have important consequences on the quantity and quality of offspring produced. Our work includes decisions on when to start breeding, where to breed, composition of the egg and the structure of the eggshell and parental care during incubation. I am interested in the variation in these decisions in relation to past breeding effort, body condition, parental age, homozygosity and environmental conditions. To investigate variation in incubation effort I developed non-invasive data loggers that can record the heart rate of incubating birds as well as the embryo.

Reviews on egg formation and incubation

  • Reid, J.M., Monaghan, P. & Nager, R.G. 2002. Incubation and the cost of reproduction. In Avian Incubation: Behaviour, Environment, and Evolution (D. C. Deeming, ed.). Oxford University Press, pp. 314-325.
  • Nager, R.G., Monaghan, P., Houston, D.C., Arnold, K.E., Blount, J.D. & Verboven, N. 2006. Maternal effects through the avian egg. Acta Zoologica Sinica 52 (Supplement),658-661.
  • Nager, R.G. 2006. The challenges of making eggs. Ardea 94,323-346.

Timing of breeding

  • Nager, R.G. 1990. On the effects of small scale variation in temperature and food availability on laying date and egg-size in Great Tits (Parus major). In: J. Blondel, A. Gosler, J.D. Lebreton & R. McCleery (eds.) Population Biology of Passerine Birds. Pp. 187-197. Springer, Berlin Heidelberg.
  • Nager, R.G. & van Noordwijk, A.J. 1992. Energetic limitation in the egg-laying period of Great Tits. Proceedings of the Royal Society, London, Series B. 249:259-263.
  • Nager, R.G. 1994. Plasticity of Great Tit's laying date: effects of local temperature and food availability. Journal für Ornithologie 135:345.
  • Nager, R.G. & Zandt, H.S. 1994. Variation in egg size in Great Tits. Ardea 82:315-328.
  • Nager, R.G. & van Noordwijk, A.J. 1995. Proximate and ultimate aspects of phenotypic plasticity in timing of Great Tit breeding in a heterogeneous environment. American Naturalist 146:454-474.
  • Nager, R.G., Rüegger, C. & van Noordwijk, A.J. 1997. Nutrient or energy limitation on egg formation: a feeding experiment in great tits. Journal of Animal Ecology 66:495-507.
  • Nager, R.G., Keller, L. F. & van Noordwijk, A. J. 2000. Understanding natural selection on traits that are influenced by environmental conditions. In: Adaptive Genetic Variation in the Wild (T.A. Mousseau, B. Sinervo & J.A Endler, eds.). Oxford University Press, Oxford, pp. 95-115.

Maternal effects and life history

  • Cézilly, F. & Nager, R.G. 1995. Comparative evidence for a positive association between divorce and extra-pair paternity in birds. Proceedings of the Royal Society, London, Series B. 262:7-12.
  • Cézilly, F. & Nager, R.G. 1996. Age and breeding performance in monogamous birds: the influence of pair stability. Trends in Ecology and Evolution 11:27.
  • Monaghan, P. & Nager, R.G. 1997. Why don’t birds lay more eggs? Trends in Ecology and Evolution 12:270-274.
  • Heaney, V., Nager, R.G. & Monaghan, P. 1998. Effect of increased egg production on egg composition in the common tern Sterna hirundo. Ibis 140:693-696.
  • Monaghan, P., Nager, R.G. & Houston, D.C. 1998. The price of eggs: increased egg production reduces offspring rearing capacity. Proceedings of the Royal Society, London, Series B. 265:1731-1735.
  • Nager, R.G., Monaghan, P. & Houston, D.C. 2000. Within-clutch trade-offs between clutch size and egg quality: an experimental study on gulls. Ecology 81:1339-1350.
  • Nager, R.G., Monaghan, P. & Houston, D.C. 2001. The cost of egg production: Increased egg production reduces future fitness in gulls. Journal of Avian Biology 32: 159-166.
  • Blount, J.D., Surai, P.F., Nager, R.G, Houston, D.C., Moller, A. P., Trewby, M. L. & Kennedy, M.W. 2002. Carotenoids and egg quality in the lesser black-backed gull Larus fuscus: a supplemental feeding study of maternal effects. Proceedings of the Royal Society, London, Series B 269: 29-36.

Sex ratio

  • Nager, R.G., Monaghan, P., Griffith, R., Houston, D.C. & Dawson, R.J. 1999. Experimental demonstration that offspring sex ratio varies with maternal condition. Proceedings of the National Academy of Science, U.S. 96:570-573.
  • Nager, R.G., Monaghan, P., Houston, D.C. & Genovart, M. 2000. Parental condition, brood sex ratio and differential young survival: an experimental study in gulls. Behavioural Ecology and Sociobiology 48:452-457.
  • Kalmbach, E., Nager, R.G., Griffiths, R. & Furness, R.W. 2001. Increased reproductive effort results in male-biased offspring sex ratio: an experimental study in a species with reversed sexual size dimorphism. Proceedings of the Royal Society, London, Series B 268: 2175-2179.
  • Genovart, M., Oro, D., Ruiz, X., Griffiths, R, Monaghan, P. & Nager, R.G. 2003. Seasonal changes in brood sex composition in Audouin's gulls. Condor 105: 783-790.
  • Rutstein, A., Gorman, H.E. Arnold, K., Gilbert, L., Orr, K., Adam, A., Nager, R.G. & J Graves 2005. Sex allocation in response to paternal attractiveness in the zebra finch. Behavioral Ecology 16: 763-769.

Past and current group members:

Helen Gorman - Maternal effect in avian incubation

  • Gorman, H.E. & Nager, R.G. 2003. State-dependent incubation behaviour in the zebra finch. Animal Behaviour.65: 745-754.
  • Gorman, H.E. & Nager, R.G. 2004. Prenatal developmental conditions have long-term effects on offspring fecundity. Proceedings of the Royal Society, London, Series B. 271: 1923-1928.
  • Gorman, H.E. Arnold, K.E. & Nager R.G. 2005. Incubation effort in relation to male attractiveness in zebra finches (Taeniopygia guttata). Journal of Avian Biology 36: 413-420.
  • Gorman, H.E., Orr, K.J., Adam, A. & Nager, R.G. 2005. Effects of incubation conditions and offspring sex on embryo development and survival in the zebra finch. Auk 122,1239-1248.

Sarah Davies - Sensitivity of seabird populations to changes in life history parameters

  • Davis S.E., Nager R.G. & Furness R.W. 2005. Food availability affects life-history parameters of Parasitic Jaegers. Ecology 86: 1047-1056.

Nanette Verboven - Maternal condition, egg testosterone and offspring  fitness in gulls

  • Verboven, N., Monaghan, P., Evans, D.M., Schwabl, H., Evans, N., Whitelaw, C. & Nager, R.G. 2003. Maternal condition, yolk androgens and offspring performance: a supplemental feeding experiment in the lesser black-backed gull. Proceedings of the Royal Society, London, Series B 270: 2223-2232.
  • Verboven N., Evans, N., d’Alba L., Nager, R.G., Blount, J.D., Surai, P.F. & Monaghan, P. 2005. Intra-specific interactions influence egg composition in the lesser black-backed gull (Larus fuscus). Behavioural Ecology and Sociobiology 57: 357-365.

Mike Fisher - Environmental effects on female fecundity and the dynamics of mate choice

  • Fisher, M.O., Nager, R.G. & Monaghan, P. 2006. Compensatory growth impairs adult cognitive performance. PLoS Biology 4,1462-1466.

Maria Bogdanova - Age, Maternal Effects and Egg production

  • Bogdanova, M.I., Nager, R.G. & Monaghan, P. 2006. Does parental age affect offspring performance through differences in egg quality? Functional Ecology 20,132-141.
  • Bogdanova, M.I., Nager, R.G. & Monaghan, P. 2007. Age of the incubating parent influences nestling survival: an experiment in the herring gull (Larus argentatus). Journal of Avian Biology 38,83-93.

Kampanat Tharapoom - Causes and consequences of variation in avian eggshells

Hannah Montag - Nest site characteristic of the dusky orange-crowned warbler endemic to Santa Catalina Island

  • Montag, H., Nager, R.G., Ghalambor, C.K. and Sillett, T.S. 2009. Nest site selection of the endemic «dusky» orange-crowned warbler (Vermivora celata sordida) on Santa Catalina Island. Proceedings of the 7th California Islands Symposium

Liliana d'Alba - Energetic consequences of nest structure and microclimate in the common eider

  • D'Alba, L., Monaghan, P. and Nager, R.G. 2009. Thermal benefits of nest shelter for incubating female eiders. Journal of Thermal Biology 34,93-99.
  • D'Alba, L., Monaghan, P. and Nager, R.G. 2010. Advances in laying date and increasing population size suggest positive responses to climate change in Common Eiders Somateria mollissima in Iceland. Ibis 152,19-28.

Terje Lislevand - Avian incubation

Emma Lowe - Heterozygosity and egg quality