Aggregative response in bats: prey abundance versus habitat

Area of Science:

• Ecology
• Behavioral Ecology
• Zoology

Background:

• Predators in prey-scarce environments require adaptations for efficient foraging.
• Open-habitat foragers, like certain bats, possess traits for long-distance travel and may use social information to find prey.
• An aggregative response to prey availability is expected in these predators.

Purpose of the Study:

• To investigate how prey abundance influences the foraging behavior of open-habitat foraging bats.
• To compare the foraging strategies of open-habitat foragers with edge- and closed-habitat foragers.
• To determine if habitat adaptations constrain foraging in resource-rich areas.

Main Methods:

• Bat foraging activity was quantified using 38,371 recorded foraging calls.
• Prey abundance was assessed using light and pitfall traps at various sites.
• Habitat structure was analyzed using terrestrial laser scanning.

Main Results:

• Prey abundance positively correlated with vegetation density.
• Open-habitat bat activity decreased significantly with increasing vegetation density.
• Edge- and closed-habitat foragers showed no significant response to vegetation density.
• Only open-habitat foragers exhibited a proportional aggregative response to prey abundance.

Conclusions:

• Open-habitat foragers' adaptations for efficient, low-cost foraging in open areas restrict their ability to utilize dense habitats.
• These specialized foraging strategies exclude open-habitat bat guilds from high-prey-density environments like dense forests.
• Habitat specialization influences predator-prey dynamics and resource utilization patterns.