Nature ecology & evolutionSep 22, 2026

Mating urges change daily activity patterns in fruit flies

Circadian Biology Weekly Brief ↗PubMed ↗DOI ↗

Updated Sep 24, 2026

Abstract

Intense sociosexual interactions can rapidly alter the activity patterns of Drosophila species, shifting their behaviors from crepuscular to either nocturnal or diurnal timeframes.

Chemical signals used for courtship push some species to become active at night, while those relying on visual cues shift their activity to the day.
This change in activity patterns occurs independently of the circadian clock.
A conserved pathway involving dopamine is linked to both the reduction of sleep and the increase in sexual motivation.
These findings suggest that mating behaviors can enable species to occupy different time slots, allowing them to coexist in the same environment.

Simplified

Animals confine their daily activity to distinct diurnal, crepuscular or nocturnal windows. It remains unclear how hundreds of sympatric species sharing the same temporal niche manage to coexist. To address this, we monitored the daily activity of the twilight-active, species-rich Drosophila genus under naturalistic conditions. Here we show that intense sociosexual interactions rapidly drive a species-specific reformatting of their canonical crepuscular niche. The dominant sensory modality used for sexual communication predicts niche-shift direction: reliance on chemosensation for courtship redirects behavioural activity into the night, while visual reliance shifts it into the day. This temporal plasticity bypasses the circadian clock, instead operating via a conserved dopaminergic pathway that simultaneously inhibits sleep and sustains sexual motivation. Our results reveal how mating imperatives enable conditional colonization of otherwise restricted temporal windows. Ultimately, by driving the divergence of previously overlapping niches, sociosexually induced temporal plasticity provides a powerful mechanism for sympatric coexistence in crowded environments.