Population model for Common eiders breeding at the East Bay colony, Southampton Island, Canada.

<p><b>A.</b> Life cycle of common eiders (Southampton Island, Nunavut, Canada) based on three age classes. The population matrix <i>A</i> contains the vital rates and projects the population from time <i>t</i> to <i>t</i>+1. The fertility parameter was calculated as the product between the breeding probability (<i>BP</i>), the average breeding success (<i>BS</i>) and the average number of hatchlings per breeding female (<i>f</i>). <i>S_A</i> represents adult survival (survival from 2 years of age onwards), <i>S_Y</i> survival of yearlings (from 1 to 2 years of age) and <i>S_H</i> survival of hatchlings (from hatching to 1 year of age). We considered four different periods based on cholera severity; demographic parameters for each period are shown in <b>B.</b>