Predators modify the temperature dependence of life-history trade-offs

Thomas M. Luhring, Janna M. Vavra, Clayton E. Cressler, John P. DeLong

Research output: Contribution to journalArticle

4 Scopus citations

Abstract

Although life histories are shaped by temperature and predation, their joint influence on the interdependence of life-history traits is poorly understood. Shifts in one life-history trait often necessitate shifts in another—structured in some cases by trade-offs—leading to differing life-history strategies among environments. The offspring size–number trade-off connects three traits whereby a constant reproductive allocation (R) constrains how the number (O) and size (S) of offspring change. Increasing temperature and size-independent predation decrease size at and time to reproduction which can lower R through reduced time for resource accrual or size-constrained fecundity. We investigated how O, S, and R in a clonal population of Daphnia magna change across their first three clutches with temperature and size-independent predation risk. Early in ontogeny, increased temperature moved O and S along a trade-off curve (constant R) toward fewer larger offspring. Later in ontogeny, increased temperature reduced R in the no-predator treatment through disproportionate decreases in O relative to S. In the predation treatment, R likewise decreased at warmer temperatures but to a lesser degree and more readily traded off S for O whereby the third clutch showed a constant allocation strategy of O versus S with decreasing R. Ontogenetic shifts in S and O rotated in a counterclockwise fashion as temperature increased and more drastically under risk of predation. These results show that predation risk can alter the temperature dependence of traits and their interactions through trade-offs.

Original languageEnglish (US)
Pages (from-to)8818-8830
Number of pages13
JournalEcology and Evolution
Volume8
Issue number17
DOIs
StatePublished - Sep 2018

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Keywords

  • allocation
  • fecundity
  • fitness
  • phenotypic plasticity
  • predation
  • reproduction
  • thermal reaction norm

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Ecology
  • Nature and Landscape Conservation

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