| Popis: |
The nonlethal effects of predation threat can be pervasive but are also easily overlooked. We investigated effects of predation threat on feeding by guppies (Poecilia reticulata), and how threat-induced temporal shifts in feeding activity affect reproductive behavior and growth. Contrary to the view of the guppy as a “diurnal” species, our observations revealed that guppies free from severe predation threat expand their foraging into the nocturnal period. We found such nocturnal foraging to be as profitable as diurnal foraging, and guppies under threat incurred a substantial growth penalty when predators inhibited night feeding. Denial of night feeding also decreased daytime courtship by males, facultatively duplicating a classical observation comparing courtship intensity in contrasting predator regimes, but providing a novel mechanism for the effect. Our findings support the view that evaluations of predator effects on life histories should consider potential predator-caused alterations in size-specific... |
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