When a large mammal, like a deer or moose, is hit by a car, the impact is not only dramatic but also tragic. To combat these serious incidents, transportation officials have partnered with wildlife researchers to install warning signs and build tunnels and bridges for wildlife, aiming to prevent accidents along migration routes.
In contrast, collisions with much smaller creatures like bees often go unnoticed by drivers or are dismissed as mere splatters on windshields. However, Utah State University researcher Joseph Wilson emphasizes that the implications of these small incidents are far more significant than many realize.
“Bees play a pivotal role in our ecosystem,” says Wilson, an evolutionary ecologist and professor in the Department of Biology at USU Tooele. “The consequences of their frequent collisions with vehicles extend well beyond a minor travel inconvenience. In fact, the impacts of bee deaths, occurring minute-by-minute each day, may have a greater negative impact than we realized.”
The recent study by Wilson and his team reveals that tens of millions of bees may tragically die each day as cars speed along busy highways in the western United States. In their preliminary findings Wilson, along with USU graduates Thomas Porter and Olivia Messinger Carril, highlights a pressing environmental concern.
“Unlike collisions with larger animals that are easy to measure, it is much harder to detect the extent of bee mortality caused by moving vehicles,” Wilson says.
The researchers utilized sticky traps mounted on car bumpers and extended their findings based on statistics from the Department of Transportation. Wilson notes that the high estimates of bees being struck were quite alarming.
“Roadsides, especially those in arid landscapes, have more flowering plants due to water runoff from roads,” Wilson says.
In desert environments, these roadside plant communities frequently support a wide variety of bee populations. Additionally, the research indicates that roads with the highest estimates of bee fatalities are often located close to national parks, where visitor numbers have surged along with the influx of vehicles.
“The quality of the roadside habitat, however, determines if insects stay along the roadside or if they decide to cross the road, looking for better places to forage,” he says.
Raising awareness about the significance of bees, along with an increasing number of studies indicating that some bee populations are on the decline, has prompted both public managers and private organizations to advocate for plantings along roadsides and in medians.
“This may not be the best solution in all areas if those plantings encourage insects to cross roads to access those resources,” Wilson says.
A complex dilemma arises regarding how to establish bee-friendly habitats without further endangering bees.
“We’ve raised a lot of questions,” Wilson says. “More research is needed to better understand how roads and roadside habitats are impacting insect movement, along with ways roadway design and maintenance, as well as vehicle designs, can be less detrimental to these pollinators.”
Fortunately, not all news is bleak. “Some studies show healthy roadside habitat facilitates movement of pollinators along the road,” Wilson says. “So, with some awareness, landscapes can be restored along roadways to support pollinator communities and reduce the need for road crossings.”
Still, habitat modification, habitat fragmentation and habitat loss are taking a grim toll on pollinator populations, he says.
“Bees are keystone species that support plant diversity and reproduction,” Wilson says. “Understanding how we can support pollinators at a landscape scale is an important step towards the protection of these important insects.”
Journal reference:
- Jospeh S. Wilson, Thomas Porter & Olivia Messinger Carril. Are vehicle strikes causing millions of bee deaths per day on western United States roads? Preliminary data suggests the number is high. Sustainable Environment, 2024; DOI: 10.1080/27658511.2024.2424064