A larval aggregation pheromone as foraging cue for insectivorous birds

Area of Science:

• Ornithology
• Chemical Ecology
• Behavioral Ecology

Background:

• Birds were traditionally thought to have a poor sense of smell (anosmic).
• Recent evidence suggests olfaction is crucial for insectivorous birds' foraging strategies.
• Birds can detect plant volatiles and insect pheromones to find adult prey.

Purpose of the Study:

• To investigate if insectivorous birds can detect chemical cues from immature insects.
• To determine if birds use larval aggregation pheromones to locate prey.

Main Methods:

• Field experiments were conducted in a Chilean sclerophyllous forest.
• Artificial larvae baited with carpenter worm (Chilecomadia valdiviana) larval pheromone or solvent (control) were placed on trees.
• Bird predation on artificial larvae was assessed by counting peck damage.

Main Results:

• Significantly more artificial larvae were damaged by bird pecks when treated with larval pheromone compared to controls.
• This indicates birds can detect and respond to chemical cues from immature insects.

Conclusions:

• Birds can utilize immature insect-derived chemical cues, specifically aggregation pheromones, for prey detection.
• This olfactory ability plays a role in the foraging behavior of insectivorous birds, particularly for immature insect stages.