BISC101_2012

Physiological Adaptations for Breeding in Birds (2012) provides a critique of the state of our knowledge of the “physiological mechanisms that regulate individual or phenotypic variation in reproductive life-history traits, trade-offs between these traits, and trade-offs and carry over effects between different life-history stages”. It develops two main themes: that avian reproductive physiology and ecology must be considered from a female perspective and that we need to focus on individual variation in the physiology underpinning life-history traits. I conclude that we have only a very rudimentary, and in some cases non-existent, understanding of the mechanisms underpinning those traits which population studies have shown are most closely related to individual variation in fitness:

       timing of breeding
        clutch size
        parental care

Heritable, individual variation is the raw material for evolution by natural selection, it is the critical level of analysis in many evolutionary studies, and it needs to become the key focus in physiological and endocrine analysis of life-history traits. Despite an increased interest in the integration of behavioural ecology, evolutionary biology, and physiology progress has been slow especially for avian reproduction. Physiological Adaptations argues strongly that we need a shift of focus in research on avian reproduction if we are to successfully integrate physiology and ecology, and it lays out a specific research agenda to achieve this.

Our work mainly focus on avian reproduction (though not exclusively!) and specifically early stages of reproduction (e.g. timing of breeding and egg formation) since the importance of this phase of breeding has been neglected and underestimated. Research primarily combines laboratory studies, using captive breeding zebra finches (Taeniopygia guttata), with studies of a free-living, nest-box breeding, population of European starlings (Sturnus vulgaris) which are ideal for experimental studies in the field. However, we have been involved in other projects on a wide range of species including Arctic-nesting ducks and geese, seabirds, penguins, albatrosses (and even blue tits).

Williams T.D. and Groothuis, T.G.G. 2015. Egg quality, embryonic development and post-hatching phenotype: an integratedperspective. In: Deeming D.C. and Reynolds, S.J. (eds.) Nests, eggs and incubation: New ideas about avian reproduction. Oxford University Press, pp. 114-126
Williams, T.D. & Fowler, M.A. 2015. Individual Variation in Workload During Parental Care: Can We Detect A Physiological Signature of Quality orCost of Reproduction? Journal of Ornithology 156 (Suppl 1):S441–S451.
Williams, T.D. 2012. Hormones, life-history, and phenotypic variation: opportunities in evolutionary avian endocrinology. Gen. Comp. Endocrinol. 176: 286-295.
Williams, T.D. 2008. Individual variation in endocrine systems: moving beyond the “tyranny of the Golden Mean”. Phil. Trans. Roy. Soc. B. 363: 1687-1698.
Williams, T.D. 2005. Mechanisms underlying costs of egg production. BioScience 55: 39-48.
Williams, T.D. & Vezina, F. 2001. Reproductive energy expenditure, intraspecific variation, and fitness. Current Ornithology 16: 355-405

1. Timing of breeding, temperature and prey availability in European starlings

2. Physiological mechanisms for clutch size determination

3. Individual quality, workload and physiological mechanisms of parental care in European starlings

4. Hormonally-mediated maternal effects and telomere dynamics during early development (collaboration with Francois Criscuolo and Mathilde Tissier, University of Strasbourg, France)

5. Breeding biology of barn and tree swallows in relation to habitat (collaboration with Nancy Mahony, Environment Canada)

6. Effects of mercury on growth, development and reproduction in birds (collaboration with John Elliott, Environment Canada)

7. Effects of bitumen oil products on growth, development and reproduction in birds (collaboration with John Elliott, Environment Canada)

Cornell, A., Hou, J.J. and Williams, T.D. In press. Experimentally-increased pre-breeding male social behaviour has no effect on female breeding phenology and performance. Animal Behaviour

Crossin, G.T. and Williams, T.D. 2016. Migratory life-histories explain the extreme egg-size dimorphism of Eudyptes penguins. Proc. R. Soc. Lond. B 283:20161413

Cornell, A., Gibson, K. and Williams T.D. In press. Physiological maturity at a critical life-history transition and post-fledging flight ability. Functional Ecology

Fronstin, R.B., Christians, J.K., and Williams, T.D. 2016. Experimental reduction of hematocrit affects reproductive performance in European starlings, Sturnus vulgaris. Functional Ecology 30: 398-409.

Crossin, G.T., Love, O.P., Cooke, S.J. and Williams, T.D. 2016. Glucocorticoid manipulations in free-living animals: considerations of dose delivery, life-history context, and reproductive state. Functional Ecology 30: 116–125.

Williams, T.D. & Fowler, M.A. 2015. Individual Variation in Workload During Parental Care: Can We Detect A Physiological Signature of Quality or Cost of Reproduction? Journal of Ornithology 156 (Suppl 1):S441–S451.

Fowler, M.A. and Williams, T.D. 2015. Individual variation in parental workload and breeding productivity in female European starlings: is the effort worth it? Ecology and Evolution 5: 3585–3599, doi: 10.1002/ece3.1625 (open access).

Ryan, C.P., Dawson, A., Sharp, P. and Williams, T.D. 2015. Uncoupling variation in clutch size and plasma prolactin using experimental egg removal. Gen. Comp. Endocrinol. 213: 1-8.

Williams, T.D., Bourgeon, S., Cornell, A., Ferguson, L., Fowler, M.A., Fronstin, R.B. and Love, O.P. 2015. Mid-winter temperatures, not spring temperatures, predict breeding phenology in the European starling Sturnus vulgaris. Royal Society Open Science. 2: 140301.

Perfito, N., Guardado, D., Williams, T.D. and Bentley, G. 2015. Social cues regulate reciprocal switching of hypothalamic Dio2/Dio3 and the transition into final follicle maturation in European starlings (Sturnus vulgaris). Endocrinology 156:694–706 4.866

Ryan, C.P., Dawson, A., Sharp, P., Meddle, S.L. and Williams, T.D. 2014, Circulating breeding and pre-breeding prolactin and LH are not associated with clutch size in the Zebra Finch (Taeniopygia guttata). Gen. Comp. Endocrinol. 202: 26–34.

Tissier, M.L., Williams, T.D., & Criscuolo, F. 2014. Maternal effects underlie ageing costs of growth in the zebra finch (Taeniopygia guttata). PLoS ONE 9: e97705

Ryan, C.P., Dawson, A., Sharp, P., Meddle, S.L. and Williams, T.D. 2014. Circulating breeding and pre-breeding prolactin and LH are not associated with clutch size in the Zebra Finch (Taeniopygia guttata). Gen. Comp. Endocrinol. 202: 26–34.

Gorman, K.B., Williams, T.D. & Fraser, W.R. 2014. Ecological Sexual Dimorphism and Environmental Variability within a Community of Antarctic Penguins (genus Pygoscelis). PLoS ONE 9: e90081

Love, O.P., Bourgeon, S., Madliger, C.L., Semeniuk, C.A.D. & Williams, T.D. 2014. Evidence for baseline glucocorticoids as mediators of reproductive investment in a wild bird. Gen. Comp. Endocrinol. 199: 65–69.

Crossin, G.T., Phillips, R.A., Wynne-Edwards, K. & Williams, T.D. 2013. Post-migratory body condition predicts ovarian steroid production and breeding decision in female gray-headed albatrosses. Physiol. Biochem. Zool. 86: 761-768

Crossin, G.T., Phillips, R.A., Lattin, C.R., Romero, M. & Williams, T.D. 2013. Corticosterone mediated costs of reproduction link current to future breeding. Gen. Comp. Endocrinol. 193: 112–120.

Stein, R.W. & Williams, T.D. In press. Extreme intraclutch egg-size dimorphism in Eudyptes penguins, an evolutionary response to clutch-size maladaptation. Amer. Nat.. 182: 260-270

Crespi, E.J., Williams, T.D., Jessop, T.S. & Delehanty, B. 2013. Life history and the ecology of stress: how do glucocorticoid hormones influence life-history variation in animals? Funct. Ecol. 27, 93–106.

Zanette, L.Y., Hobson, K.A., Clinchy, M., Travers, M. & Williams, T.D. 2013. Food use by songbirds is affected by the experience of nest predation: implications for indirect predator effects on clutch size. Oecologia 172:1031–1039

The main aims of the Center for Wildlife Ecology's research in ecological physiology are three-fold: 1) to obtain a better understanding of the fundamental mechanisms underlying individual and population-level variation in physiological traits in order to provide a solid basis for predicting how animals might respond to environmental change, 2) to determine more meaningful intra-specific measures of body condition, quality and individual health for birds, and 3) to develop and apply new physiological approaches and techniques to conservation biology and ecotoxicology. We approach these aims through a combination of studies on basic physiology, often using tractable model systems (e.g. zebra finches) as well as free-living birds (starlings, western sandpiper), coupled with more applied, and more specific, goal-orientated projects (e.g. addressing current ecotoxicological problems). The following projects are on-going in the Williams' lab at present:

1. Long-term effects of early (in ovo or perinatal) exposure to xenobiotics in birds: The objectives of this research are to determine the long term effects of developmental exposure to environmentally relevant sub-lethal levels of contaminants, with a current focus on mercury (Hg). The rationale is that early life stages in birds are sensitive to environmental conditions, and factors such as anthropogenic xenobiotics can have permanent effects on the resulting phenotypes at concentrations much lower than those required to affect adults. In addition, these effects may not be seen until the individual reaches reproductive maturity, which necessitates long-term studies.

Yu, M., Elliott, J.E., Eng, M., Basu, N., and Williams, T.D. 2016. Acute embryotoxic effects but no long term reproductive effects of in ovo methylmercury exposure in zebra finches Taeniopygia guttata. Environmental Toxicology and Chemistry 35: 1534-1540.
Eng, M.L., Elliott, J.E. & Williams, T.D. 2014. An assessment of the developmental toxicity of BDE-99 in the European starling using an integrated laboratory and field approach Ecotoxicology 23:1505–1516.
Eng, M.L., Elliott, J.E., Jones, S.P., Williams, T.D., Drouillard, K.G., and Kennedy, S.W. 2014. Amino acid sequence of the AhR1 ligand-binding domain predicts avian sensitivity to dioxin like compounds: in vivo validation in European starlings. Environmental Toxicology and Chemistry 33: 2753–2758.

2. Chronic toxicity of petroleum hydrocarbons and other contaminants in seabird sentinel species: This research will focus on investigating the toxicity of petroleum, specifically oil sands bitumen products, to birds on the Pacific north-west coast. At this stage we envisage the project having a number of potential components including: a) one or more field studies of avian marine sentinel species (initially rhinoceros auklet) which will establish baseline response of a variety of genes; and, laboratory dosing studies of a representative wild species (to be determined), and c) use of an avian lab model, the zebra finch; all involving use , and further development, of gene array techniques: the Avian ToxChip developed by our collaborators at the National Wildlife Research Centre (NWRC) laboratory in Ottawa.