Evidence for diurnal habits in an exceptionally preserved Eocene owl.

An exceptionally preserved middle Eocene owl skeleton from Germany preserves an iridescent cockroach stomach content, providing the strongest evidence to date for diurnality in archaic Strigiformes.

• Why it matters: When owls became nocturnal is unclear, limiting evolutionary explanations for this distinctive behavior and the timing of its ecological origin.
• What they did: The team identified the last meal as an iridescent cockroach and assessed additional flight-related traits, including barred flight feathers, frayed primary leading edges, and humerus shape.
• The result: Iridescence linked to diurnal cockroach habits, plus missing nocturnality-associated feather features and a less silent-flight humerus, constrains when diurnal ecology characterized early owls.

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