Behavioural ecology: bees associate warmth with floral colour.

Area of Science:

• Plant-pollinator interactions
• Animal behavior
• Sensory ecology

Background:

• Floral color signals typically predict nutritional rewards like nectar for pollinators.
• Insect pollinators, such as bumblebees, expend energy to maintain body temperature.
• Floral heat may also function as a reward for thermoregulating pollinators.

Purpose of the Study:

• To investigate if bumblebees perceive floral heat as a reward.
• To determine if bumblebees can learn to use floral color as a cue for flower temperature.
• To explore the potential for floral thermoregulation as a widespread plant adaptation.

Main Methods:

• Observational studies on bumblebee visitation preferences.
• Behavioral experiments testing bumblebee learning of color-temperature associations.
• Temperature measurements of flowers in natural and experimental settings.

Main Results:

• Bumblebees (Bombus terrestris) demonstrated a preference for visiting warmer flowers.
• Bees learned to associate specific floral colors with higher temperatures before landing.
• Evidence suggests color can act as a predictive cue for floral heat.

Conclusions:

• Floral heat can be perceived as a reward by bumblebees, alongside nectar.
• Pollinators can learn to associate visual cues (color) with thermal properties of flowers.
• Plants may actively modulate their temperature to influence pollinator behavior and visitation rates.