26-05-2025
What goes ‘bump' in the night is actually helping to ensure humanity's survival
When you're asleep, the world remains awake. Thousands of nocturnal species are crawling, flying, leaping, swimming, and dancing through forests, caves, lakes, parks, and the urban environment. Without seeing them, people may not even know they're there.
Even though they're largely unseen, a new research review has found that without the contribution of the world's nocturnal pollinators, humanity would struggle to survive.
"We have this idea that all the magic happens during the day, because that's when we're active, and that's when we see bees and butterflies fluttering around flowers," Liam Kendall, a postdoctoral fellow at Sweden's Lund University, said in a statement.
Kendall and fellow researcher Charlie Nicholson were the authors of the first-of-its-kind meta-analysis which was published this month in the journal Ecology Letters.
Most people know about daytime pollinators, including birds, bees, wasps, and butterflies. They provide critical ecosystem services, working to fertilize flowers that can create fruit and seeds. Without their services, humanity would be in dire straits. One in three bites of the food Americans eat depends on pollinators. Furthermore, nearly 80 percent of global crop plants used to make food and other plant-based products require pollination by animals.
For decades, scientists have tried to determine whether plants are largely pollinated during the day or at night. But, less attention has been given to the bats, months, nocturnal butterflies, and fireflies.
To understand their role compared to their daytime counterparts, Kendall and Nicholson compiled data from 135 studies, finding that 90 percent of the 139 plant species that were examined in the studies had similar reproductive success, regardless of when the plants were pollinated.
"We were definitely surprised by the number of plant species where it didn't matter. We found this really fascinating because it's easy to assume that a specific plant needs a specific pollinator. The analysis actually showed almost the opposite — there's much more flexibility. A different pollinator than expected can contribute enough for a plant species to reproduce," said Kendall.
So, why has their impact taken so long to widely recognize?
In fact, it hasn't been totally unrecognized.
Moths have been called the 'unsung heroes of pollination,' many of which are tied to apple pollination. The white-lined sphinx moth, which is also known as the hummingbird moth, is a crucial pollinator for twilight-blooming flowers, according to Mass Audubon. They are widespread in North America. Plus, hundreds of species of plants rely on U.S. bats, including bananas, mangos, and agave.
Kendall theorizes that daytime pollinators are seen by humans as more 'beautiful,' and attract more attention. Furthermore, he hypothesizes that many researchers may have had a certain idea for how pollination for a particular plant may occur. Of course, it is also notable that humans are most active during the daytime.
The authors also highlighted that daytime species are better protected than nighttime species. Tackling artificial light at night — or excessive or poorly placed lighting that can interrupt the natural environment — may be one way to help protect them. They also face exposure to pesticides, disease, invasive species, climate change, and habitat loss.
Climate change is disrupting the relationship between all pollinators and plants, with rising temperatures affecting when plants flower and potentially getting them out of sync with their pollinators.
"Actions are often taken to protect daytime pollinators, such as spraying pesticides at night. There's an oversight there — sure, you're protecting the daytime insects, but you're also, theoretically, harming the nocturnal pollinators. This means we could be doing much more, but we haven't thought enough about it so far, and more research is needed," said Kendall.
