The study, published in Royal Society of Publishing, titled ‘Dim-light colour vision in the facultatively nocturnal Asian giant honeybee, Apis dorsata’ has put forth some new discoveries.
Certain moths and a type of bee, the carpenter bee, were previously found to actually see colours in low light, suggesting that they have special adaptations for seeing in the dark. Understanding how these insects see colour at night can tell us a lot about their eyes and how they interact with flowers during nighttime, which is important because bees play a big role in pollinating plants, even at night.
Nocturnal vision challenges and the new discovery
Humans switch from seeing colours during the day to just seeing shades of grey at night. Insects that visit flowers at night also face similar challenges. However, some insects have evolved unique ways to overcome these obstacles. For instance, certain moths have eyes that let in more light, making it easier for them to see in the dark. Even though the carpenter bee’s eyes are not ideal for seeing in low light, it can still see colours at night, which is quite remarkable.
Some honeybees, like the Asian giant honeybee (Apis dorsata), can see colours even in very low light conditions, like during half-moon nights. Earlier perception of insects being able to sense flowers and the like primarily through smell has been set aside.
How bees see colour
The authors of the paper performed some experiments to understand how these bees see colours in low light. It was found that the relative brightness of the colour isn’t a reliable cue for the bees, especially when the light changes quickly in dim-light conditions. This means they can’t just rely on how bright a colour is to detect it. Despite this challenge, the bees were still able to recognize and prefer certain colours, even in very low light.
This discovery makes Asian giant honeybees the second insect with eyes like theirs that can see colours in low light. The first one was the carpenter bee. Interestingly, the Asian giant honeybee’s ability to see colours in dim light is similar to how humans can see colours in such conditions.
Why does bees’ nocturnal vision matter?
Bees are crucial pollinators that help plants produce fruits and seeds. They visit flowers to collect nectar and pollen, transferring pollen between flowers as they go. This process is vital for plants to reproduce and produce the food that we eat. So, understanding how bees interact with flowers and how they see colours, especially at night, is essential for conserving our environment and food sources.
Why would some bees have evolved night vision?
Bees, like many other organisms, evolve traits and abilities in response to environmental pressures and survival advantages. The ability to see in the dark, also known as nocturnal vision, is generally more useful for creatures that are active during nighttime or low-light conditions. Bees, however, are primarily diurnal creatures, meaning they are active during the day and rest at night.
But, as put forth before, evolution is driven by the need to adapt to specific environmental conditions and niches.
Evolutionary adaptations are shaped by challenges and opportunities present in an organism’s habitat. If we see that the bees have evolved to see in dim light conditions, the first possible reason could be competition within the group. When one group/species becomes more dominant and tends to claim food resources, the other has to find alternatives for fetching food to sustain.
Apart from competition over resources, avoiding predators could be another reason why bees could have evolved night vision. Further, if that particular species had been preyed upon by nocturnal predators, night vision would help to detect threats and evade predation more effectively, increasing the chances of survival.
