Barn owl color morphs hunt differently in moonlight.

Area of Science:

• Ecology
• Evolutionary Biology
• Animal Behavior

Background:

• Bright coloration in predators poses a paradox, as high visibility may decrease hunting success.
• Camouflage and startle coloration are proposed explanations for this paradox.
• Barn owls (Tyto alba) exhibit plumage polymorphism, serving as a model for studying coloration's adaptive significance.

Purpose of the Study:

• To investigate the role of plumage color in mediating moonlight-dependent hunting behavior and performance in barn owls.
• To test whether conspicuous coloration can be advantageous in specific light conditions.

Main Methods:

• High-resolution biologging was used to track 69 male barn owls over 354 nights.
• 17,600 hunting attempts were recorded during chick provisioning.
• Plumage color variation (reddish to white) was correlated with hunting strategies under different moonlight intensities.

Main Results:

• White barn owls adjusted hunting behavior under bright moonlight, orienting attacks towards the moon and favoring brighter, unshaded areas.
• Reddish barn owls showed less adjustment, remaining more cryptic.
• While per-attack success was similar, white males achieved higher nightly prey capture rates under bright moonlight.

Conclusions:

• The findings support the startle coloration hypothesis over pure background-matching for conspicuous plumage in barn owls.
• Conspicuous plumage can be integrated into a light-dependent hunting strategy.
• Lunar lightscapes may drive the evolution of animal coloration.