Divergence in Heliconius flight behaviour is associated with local adaptation to different forest structures

Area of Science:

• Ecology
• Evolutionary Biology
• Behavioral Ecology

Background:

• Microhabitat choice and behavioral shifts are crucial for biodiversity patterns and early speciation.
• Flight height stratification in butterflies is important for maintaining community diversity.
• The role of behavioral shifts in response to habitat structure during early speciation remains understudied.

Purpose of the Study:

• Investigate variation in flight height behavior in two closely related Heliconius species (H. erato cyrbia and H. himera).
• Determine if differences in flight height are due to individual responses to resource distribution or genetically determined foraging behavior.
• Assess the role of habitat-dependent behavioral divergence in early speciation.

Main Methods:

• Quantified differences in flight height and forest structure across an environmental gradient.
• Tested the importance of plant resource distribution in explaining flight behavior.
• Utilized common garden experiments to differentiate between individual plasticity and genetic determination of foraging behavior.

Main Results:

• Two Heliconius species exhibit distinct flight heights in the wild.
• Observed differences in flight height are explained by the vertical distribution of plant resources.
• H. himera consistently flies and feeds at lower positions, mirroring resource availability, both in the wild and in captivity.

Conclusions:

• Foraging behavior, specifically flight height, may reflect local adaptation to divergent forest structures.
• Habitat-dependent divergence in foraging behavior plays a potential role in the early stages of speciation.
• Behavioral plasticity in response to resource distribution is a significant factor in speciation processes.