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. 2012. Hormones, life-history, and phenotypic variation: opportunities in evolutionary avian endocrinology. Gen. Comp. Endocrinol. 176: 286-295.
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.
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. In press. Food use
by songbirds is affected by the experience of nest predation: implications for
indirect predator effects on clutch size. Oecologia
Crossin, G.T., Poisbleau, M., Demongin, L., Chastel, O, Williams, T.D., Eens,
M. & Quillfeldt, P. 2012. Migratory constraints on yolk precursors limit
yolk androgen deposition and underlie a brood reduction strategy in rockhopper
penguins. Biol. Lett. 8: 1055-1058.
Crossin,
G.T., Trathan, P.N., Phillips, R.A., Gorman, K.B., Dawson, A., Sakamoto, K.Q.
& Williams, T.D. 2012. Corticosterone predicts foraging behavior and
parental care in macaroni penguins. Amer. Nat. 180: E31-E41
Crossin,
G.T., Phillips, R.A., Trathan, P.N., Fox, D.S., Dawson, A., Wynne-Edwards,
K.E., & Williams, T.D. 2012.
Migratory carryover effects and endocrinological correlates of reproductive
decisions and reproductive success in female albatrosses. Gen. Comp. Endocrino. 176:151–157.
Crossin, G.T., Dawson, A., Phillips, R.A., Trathan, P.N., Adlard, S., Gorman,
K.B. & Williams, T.D. 2012. Seasonal patterns of prolactin and
corticosterone secretion in an Antarctic seabird that molts during
reproduction. Gen. Comp. Endocrinol.
175: 74–81.
Vézina,
F., Williams, T.D., Piersma, T. and
Morrison, R.G.I. 2012. Phenotypic compromises in a long-distance migrant
during the transition from migration to reproduction in the High Arctic. Funct. Ecol. 26, 500–512.
Williams,
T.D., Fronstin, R.B., Otomo, A., & Wagner, E.C. 2012. Validation of the use
of phenylhydrazine hydrochloride (PHZ) for experimental manipulation of
haematocrit and plasma haemoglobin in birds. Ibis 154: 21-29.
Crossin,
G.T., Trathan, P.N., Phillips, R.A., Dawson, A., Le Bouard, F. and Williams,
T.D. 2010. A carry-over effect of migration underlies individual variation in
reproductive readiness and extreme
egg-size dimorphism in macaroni penguins. Amer.
Nat. 176: 357-366.
Travers, M. Clinchy, M.L., Boonstra, R., Zanette, L. and
Williams, T.D. 2010. Indirect predator effects on clutch size and the cost of
egg production. Ecology Letters 13:
980-988 [featured as Faculty of 1000 paper].
Salvante,
K.G., Vézina, F. & Williams, T.D. 2010. Evidence for within-individual
energy reallocation in cold-challenged, egg-producing birds. J. Exp. Biol. 213: 1991-2000.
Willie, J., Travers, M. and
Williams, T.D. 2010. Female zebra finches (Taeniopygia
guttata) are chronically, but not cumulatively, ‘anemic’ during repeated
egg-laying in response to experimental nest predation. Physiol. Biochem. Zool. 83: 119–126
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. Plasma metabolites as indicators of physiological state, condition
and habitat quality: a) Arrow Lakes Reservoir Neotropical Migrant use of the Drawdown Zone. This project uses physiological assessment of fattening rates and condition
(plasma metabolites, corticosterone) to determine effects of reservoir water
management strategies, on four species of neo-tropical migrants (Common
Yellowthroat, Yellow Warbler, Orange-Crowned Warbler, Wilson’s Warbler) in
Revelstoke, BC; b) Altitudinal differences in fattening rates in neo-tropical migrants using
high- and low-altitude sites in the Lower Mainland, BC. A paper on this collaborative
study (with Kathy Martin, Lesley Evens Ogden) was published in The Auk in January 2013. Main results
were that three frugivorous species (Fox Sparrow, Golden-crowned Sparrow and
Hermit Thrush) had 37% to 65% higher fattening rates at higher altitude sites.
In contrast, the largely insectivorous Orange-crowned Warbler had higher
fattening rates at low altitude sites. This study shows that high elevation
sites can represent high quality stopover habitats for migrants, and thus
should be given consideration for protection for songbird management and
conservation. Moreover, these patterns were only evident using plasma
metabolites analysis, not with more “traditional” analysis of body mass or fat
score, highlighting the value of these physiological approaches.
2. Ecotoxicology projects: a) Anthropogenic maternal effects: long-term
effects of early (in ovo or natal) exposure to xenobiotics in birds. We continue this long-term and highly
productive collaboration with Dr. John Elliott, S & T, largely funded via
non-CWE grants or agreements. Early life stages in birds are sensitive
to environmental conditions, and factors such as hormones and pollutants can
have long-term (permanent) effects on the resulting phenotypes at
concentrations much lower than those required to affect adults. We have developed
an integrated model system using lab-based studies of breeding zebra finches
and field-based studies of European starlings. This combines various methods of
exposure of embryos or chicks during early development (egg injection, exposure
via maternal transfer, etc), assessment of long-term effects of contaminants
when these chicks reach adulthood (mating and courtship behaviour, breeding
success), and potential intergenerational effects on the offspring of birds
exposed as chicks. More recently we have incorporated in vitro (cell-based and molecular) assays of potential endocrine
disrupting effects before we start in
vivo
testing using physiological, neurobiological, behavioural and
reproductive endpoints (with Dr. Tim Beischlag, Faculty of Health
Sciences). We
have now used this system to test to test a series of “priority”
chemicals in collaboration with colleagues at NWRC, Ottawa
(Drs. Fernie, Letcher, Kennedy), under
EC’s Chemical Management Plan (CMP); b) Surveillance and monitoring
of CMP priority compounds in key bio-indicator species. In 2008 EC
selected the European starling (Sturnus vulgaris) as the
“terrestrial” indicator species to monitor new contaminants in biota to provide
early warning support to ongoing risk assessment (under the Chemical Management
Plan). We continued to provide eggs, other samples, and breeding data, for this
monitoring from our two main starling study sites.
