Hatching fraction and timing of resting stage production in seasonal environments: effects of density dependence and uncertain season length

Many organisms survive unfavourable seasons as resting stages, some of whic h hatch each favourable season. Hatching fraction and timing of resting sta ge production are important life history variables. We model life cycles of freshwater invertebrates in temporary pools, with various combinations of uncertain season length and density-dependent fecundity. In deterministic d ensity-independent conditions, resting stage production begins suddenly. Wi th uncertain season length and density independence, resting stage producti on begins earlier and gradually. A high energetic cost of resting stages fa vours later resting stage production and a lower hatching fraction. Determi nistic environments with density dependence allow sets of coexisting strate gies, dominated by pairs, each switching suddenly to resting stage producti on on a different dare, usually earlier than without density dependence. Un certain season length and density dependence allow a single evolutionarily stable strategy, around which we observe many mixed strategies with negativ ely associated yield (resting stages per initial active stage) and optimal hatching fraction.