Circadian Influences on Pollinator Behavior and Plant Interactions

Interactions between plants and their animal pollinators are governed not only by spatial and chemical cues but also by the internal timekeeping systems that synchronise the daily activity patterns of both partners. Circadian clocks in plants regulate the timing of floral traits such as petal opening, scent emission and nectar secretion, while pollinators exhibit endogenous rhythms in locomotion, sensory responsiveness and foraging behaviour. The precise alignment of these rhythms enhances pollination efficiency and reproductive success, and underpins the stability of plant–pollinator networks across diverse ecosystems. Disruption of this temporal coordination by environmental change or anthropogenic stressors can lead to mismatches in flower availability and pollinator foraging, with consequences for biodiversity, ecosystem services and crop production.

Recent advances have delineated the molecular bases of circadian regulation in model plants and insects, revealed the role of environmental zeitgebers such as light quality and temperature in clock entrainment, and demonstrated how internal timing drives diel shifts in community composition and interaction strength. Cutting-edge imaging and tracking technologies have begun to capture fine-scale temporal dynamics, enabling near-continuous monitoring of pollinator visits throughout the 24-hour cycle. These insights collectively underscore the global significance of chronobiology in pollination ecology and point towards practical applications in agriculture and conservation, from optimising pesticide application windows to designing crop varieties with tailored floral phenology.

Research from Nature Portfolio

A study examining the hawkmoth Manduca sexta and its host plant Petunia revealed that misalignment of the moth’s circadian clock with the plant’s rhythm markedly reduces visitation rates; moths and flowers that share the same subjective time exhibit stronger foraging activity and scent responsiveness, highlighting bidirectional clock control of pollination interactions. Another investigation of pollinator communities in the Arctic summer documented robust diel activity profiles despite continuous daylight: most pollinators restrict foraging to subjective “daytime” hours, indicating the persistence of internal timing mechanisms even under extreme photic conditions. A further advance employed automated time-lapse photography to capture near-complete visitation records of lotus flowers; visits during the early morning window on the second day of anthesis were found to contribute disproportionately to seed set, illustrating how discrete circadian phases of flower receptivity and pollinator activity can determine reproductive outcomes.

Circadian Influences on Pollinator Behavior and Plant Interactions publication trend

The graph below shows the total number of articles in circadian influences on pollinator behavior and plant interactions across all publications each year (not limited to Nature Index journals).

Technical terms

Circadian clock: An internal molecular mechanism that generates ~24 hour rhythms in physiology and behaviour, synchronised to environmental cycles.

Diel cycle: The 24 hour cycle of light and dark experienced by organisms, driving daily fluctuations in environmental conditions.

Entrainment: The process by which external cues (zeitgebers) such as light intensity or temperature align an organism’s circadian clock with the environment.

Floral phenology: The timing of flowering events (e.g. bud opening, scent release) that influence pollinator attraction and plant reproductive success.

References

1. Circadian clocks of both plants and pollinators influence flower seeking behavior of the pollinator hawkmoth Manduca sexta. Scientific Reports (2018).
2. Diel-scale temporal dynamics in the abundance and composition of pollinators in the Arctic summer. Scientific Reports (2020).
3. Periodically taken photographs reveal the effect of pollinator insects on seed set in lotus flowers. Scientific Reports (2022).
4. Bumblebee foraging rhythms under the midnight sun measured with radiofrequency identification. BMC Biology (2010).
5. Bimodal activity of diurnal flower visitation at high elevation. Ecology and Evolution (2021).
6. Exploring relationships between time of day and pollinator activity in the context of pesticide use. Basic and Applied Ecology (2023).