Australian bees adapted their vision to forage at night

Ecology researchers at Flinders University have discovered two Australian bee species that forage in the dark. This is the first time that bees have been found to adapt their vision to become active at night and during twilight hours.  

The experts observed night-time foraging by nomiine bees and masked bees. Both species developed enlarged compound eyes and simple eyes that allow more light to be gathered.

The image processing ability of bees can be observed using close-up images with a high resolution. According to the researchers, improved low-light ability may exist in other Australian bee species that are secretly active at night. 

Study lead author James Dorey said the nomiine and masked bees are mostly found in Australia’s tropical north, but there could potentially be more in subtropical or even temperate conditions across the continent.

“We have confirmed the existence of at least two crepuscular bee species in Australia and there are likely to be many more that can forage both during the day and into the early morning or evening under low light conditions. It’s true that bees aren’t generally known to be very capable when it comes to using their eyes at night, but it turns out that low-light foraging is more common than currently thought,” said Dorey.

“Before this study, the only way to show that a bee had adapted to low-light was by using difficult-to-obtain behavioural observations, but we have found that you should be able to figure this out by using high-quality images of a specific bee.”

Dorey pointed out that bees which forage during dim-light conditions are understudied, so there are no reliable published records for any such Australian species.

“Our study provides a framework to help identify low-light-adapted bees and the data that is needed to determine the behavioural traits of other species. This is important as we need to increase efforts to collect bee species outside of normal hours and publish new observations to better understand the role that they play in maintaining ecosystems.”

The researchers emphasized that understanding more about the behavior of bee species will help inform strategies to protect them from the impacts of climate change.

“Global weather patterns are changing and temperatures in many parts of Australia are rising along with the risk of prolonged droughts and fires. So, we have to improve our understanding about insects pollinating at night or in milder parts of the day to avoid potential extinction risks or to mitigate loss of pollination services.”

“This also means we have to highlight the species that operate in a narrow window of time and could be sensitive to climatic changes, so conservation becomes an important concern. Because quite frankly, we have ignored these species up until now.”

The study is published in the Journal of Hymenoptera Research.

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By Chrissy Sexton, Earth.com Staff Writer