Meeting Abstract
140.4 Monday, Jan. 7 The survival cost of reproductive investment: higher fattening rates lead to increased risk of mortality to a novel disease HENNIN, H.L.*; DESCAMPS, S.; FORBES, M.R.; GILCHRIST, H.G.; BÊTY, J.; SOOS, C.; LOVE, O.P.; University of Windsor, ON; Norwegian Polar Institute, Tromsø; Carleton University, Ottawa, ON; Environment Canada, Ottawa, ON; Université du Québec à Rimouski; Environment Canada, Saskatoon, SK; University of Windsor, ON hennin@uwindsor.ca
In mixed (income-capital) breeding birds that reproduce in a seasonal environment, a combination of arrival date and arrival condition on the breeding grounds, as well as the rate of gain in condition following arrival, influence the timing of reproduction. Individuals that gain in condition the quickest lay earlier, invest in larger clutches and generally incur higher fitness. However, it has recently been shown that in the presence of a highly virulent disease higher reproductive investment is associated with higher mortality risk, although the exact mechanism(s) for this link is unclear. We studied the pre-breeding energetic physiology of an Arctic-nesting colony of Common Eiders (Somateria molissima) at East Bay Island, Nunavut during an ongoing avian cholera (Pasteurella multocida) outbreak first beginning in 2006. We collected blood samples from arrival female eiders, tracked them through reproduction, and recorded mortality in high and low cholera outbreak years. We used energetic metabolites (plasma triglycerides – TRIG) as a measure of the rate of condition gain and examined its relationship to breeding propensity, lay date and the downstream effects these traits had on survival. Higher TRIG individuals were more likely to breed and had earlier laying dates. However, individuals with higher TRIG had an increased risk of mortality regardless of breeding propensity or whether they timed reproduction to the peak of cholera outbreaks. We demonstrate that increases in physiological investment in reproduction can trade-off with survival in the presence of a highly virulent disease.
