Effects of intraguild predators on nest-site selection by prey

Area of Science:

• Ecology
• Behavioral Ecology
• Predator-Prey Interactions

Background:

• Nest-site selection balances predation risk and microhabitat quality.
• Intraguild predation's effect on nest-site selection is largely unknown.
• Classical predators influence nest-site choice, but intraguild predators may too.

Purpose of the Study:

• To investigate if intraguild predation risk influences nest-site selection in prey species.
• To test how the diurnal scincid lizard Eutropis longicaudata affects the nocturnal gecko Gekko hokouensis's nesting behavior.

Main Methods:

• Field experiment on Orchid Island, Taiwan, involving E. longicaudata and G. hokouensis.
• Both species nested in concrete wall drainage holes (one or two openings).
• Experimental exclusion of E. longicaudata to observe G. hokouensis's response.

Main Results:

• In allopatry, E. longicaudata preferred plugged holes; G. hokouensis preferred open holes.
• Excluding E. longicaudata increased G. hokouensis abundance and led to equal use of open and closed-in holes.
• Egg viability was not affected by hole type but slightly reduced in predator exclusion areas.

Conclusions:

• Intraguild predators directly influence prey nest density by altering maternal nest-site selection.
• This influence occurs even with temporal activity differences and no direct egg predation risk.
• Nest-site selection behavior is a key mechanism mediating intraguild predator-prey dynamics.