Anti-parasite treatment, but not mercury burdens, influence nesting propensity dependent on arrival time or body condition in a marine bird.
Arctic wildlife can be exposed to high mercury (Hg) levels, and are also naturally exposed to gastrointestinal parasites that can reduce condition and negatively affect reproductive output and/or survival in similar ways. Importantly, both Hg and parasites are increasing in wildlife in some Arctic regions. We studied the northern common eider duck (Somateria mollissima) to explore how Hg in association with both natural levels and experimentally reduced parasitic infections, affect reproduction and survival. Female eiders were measured, banded, and blood sampled to determine blood Hg burdens, prior to breeding. Propensity to nest, clutch size, nest survival, nest attendance, and return rates were assessed in relation to both Hg burden and parasite treatment. Neither reproduction nor return rates of females varied with Hg concentrations, but females arriving late to the colony, or in low body condition, showed increased nesting propensity when given the anti-parasite treatment as compared to placebo treatment. Our results suggest that parasites can play a critical role in decisions to invest in avian breeding annually, particularly among individuals with a late onset to breeding, and in poor condition.
Department of Biology, Carleton University, Ottawa, Ontario K1S 5B6, Canada. Electronic address: jennifpro@gmail.com.
J F
JF
Provencher
Department of Biology, Carleton University, Ottawa, Ontario K1S 5B6, Canada. Electronic address: mforbes6@gmail.com.
M R
MR
Forbes
Department of Biology, Acadia University, Wolfville, Nova Scotia B4P 2R6, Canada. Electronic address: mmallory@acadiau.ca.
M L
ML
Mallory
Environment and Climate Change Canada, Wildlife Research Division, Raven Road, Carleton University, Ottawa, Ontario K1S 5B6, Canada. Electronic address: scott.wilson@canada.ca.
S
S
Wilson
Environment and Climate Change Canada, Wildlife Research Division, Raven Road, Carleton University, Ottawa, Ontario K1S 5B6, Canada. Electronic address: grant.gilchrist@canada.ca.
H G
HG
Gilchrist
D000818:Animals; D001110:Arctic Regions; D001715:Bird Diseases / Q000188:drug therapy* / Q000469:parasitology; D001822:Body Burden; D052284:Clutch Size; D004372:Ducks / Q000469:parasitology*; D005260:Female; D008628:Mercury / Q000032:analysis*; D009425:Nesting Behavior; D010271:Parasites; D012098:Reproduction
D008628:Mercury
Arctic; Bird; Breeding decisions; Contaminants; Nesting; Parasitism