Consequences of induced hatching plasticity depend on predator community

Area of Science:

• Ecology
• Evolutionary Biology
• Herpetology

Background:

• Prey species often face trade-offs in life history timing, such as hatching or metamorphosis.
• Costs of early life stage transitions are influenced by subsequent environmental conditions, including predator presence.
• The red-eyed treefrog (Agalychnis callidryas) exhibits plasticity, hatching early in response to egg-stage threats.

Purpose of the Study:

• To investigate how early hatching in Agalychnis callidryas, triggered by terrestrial egg predators, is affected by aquatic larval predator assemblages.
• To test if diverse predator assemblages reduce the costs of early hatching compared to single predator species.

Main Methods:

• A mesocosm experiment was conducted crossing hatchling phenotype (early vs. normal hatching) with five larval predator environments.
• Predator treatments included no predators, single species (waterbugs, dragonflies, mosquitofish), and a diverse assemblage of all three.

Main Results:

• The fitness consequences of early hatching were dependent on the specific predator treatments.
• Costs associated with early hatching diminished over time in certain predation environments, particularly with waterbugs and diverse predator assemblages.
• Predator community composition critically influenced the fitness costs of life history plasticity.

Conclusions:

• Life history plasticity, such as early hatching, incurs fitness costs that are contingent on the predator community structure in the subsequent life stage.
• The impact of environmental cues on developmental timing can have complex outcomes depending on ecological interactions in later stages.