Table 1.
Vital rates used to simulate change in the adult sex ratio of eiders in Söderskär and Tvärminne populations that differ in fecundity and female survival.
Fig 1.
A two-sex age-structured population model for the eider.
Vital rates are: breeding probabilities for different age classes (P2–5), proportion of males among hatched ducklings (R), juvenile survival from hatchling to one-year of age (Sj), fecundity (F), survival of different age classes for females (Sf1–5) and for males (Sm1–5).
Fig 2.
Mean adult male proportions of the eider resulting from stochastic simulations at three sites (in rows) with different survival probabilities for females (Sf2–5 in parentheses) and for males (88%, 90% or 92%).
Each scenario is based on 100 replicated runs for 50 years with three alternative male survival probabilities applied either simultaneously to age classes 1–5 (the first panel) or separately to each age class (panels 2–6). Error bars are omitted for clarity and T denotes the Tvärminne population.