Nav: Home

Does city life make bumblebees larger?

August 17, 2020

Does urbanisation drive bumblebee evolution? A new study by Martin Luther University Halle-Wittenberg (MLU) and the German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig provides an initial indication of this. According to the study, bumblebees are larger in cities and, therefore, more productive than their rural counterparts. In "Evolutionary Applications", the research team reports that differences in body size maybe caused by the increasingly fragmented habitats in cities.

Over the last 200 years, the habitat of bumblebees and other insects has changed dramatically. Now they are less likely to live in rural areas but more likely to be surrounded by roads and concrete walls. "Living in a city can have both benefits and disadvantages for bumblebees. One the one hand, residential gardens and balconies, allotment gardens, botanical gardens and city parks provide rich food sources for bumblebees. On the other hand, cities are significantly warmer than their surrounding rural areas. In addition, impervious surfaces, streets and large buildings create considerably smaller habitats that are isolated from one another. These might pose a challenge to bumblebees," says Dr Panagiotis Theodorou from the Institute of Biology at MLU, who led the research at MLU and iDiv.

The team of biologists at MLU wanted to find out whether urbanisation is associated with shifts in bumblebee body size with consequences on the ecosystem service of pollination they provide. The scientists collected more than 1,800 bumblebees in nine German metropolitan areas and their rural surroundings and used potted red clover plants as reference for pollination in all locations. Their work concentrated on three locally common bumblebee species: the red-tailed bumblebee (Bombus lapidarius), the common carder bee (Bombus pascuorum) and the buff-tailed bumblebee (Bombus terrestris). The researchers measured the body size of every bumblebee they caught and counted the number of seeds produced per red clover plant. "Our results show that bumblebees from more fragmented urban areas were larger compared to their rural counterparts, by around four percent," says biologist Dr Antonella Soro from MLU. The results were similar for all three bumblebee species.

Body size is linked to an organism's metabolism, life history, space use and dispersal as well as a major determinant of species interactions, including pollination. "Larger bumblebees can see better, they have larger brains and they are better in learning and memory. They are also less likely to be attacked by predators and can travel greater distances, which is an advantage in a fragmented landscape such as the urban one. In addition, large bumblebees visit more flowers per flight and are capable of depositing a higher number of pollen grains on stigmas, which makes them better pollinators," says Soro. This might be the explanation of the positive relationship between body size and pollination documented by the researchers. The study gives an indication that the severity of habitat fragmentation could impact a bumblebee's body size and thus also indirectly influence pollination. According to Theodorou, there are still a lot of open questions regarding the effects of urban-related environmental changes on bees and pollination. Therefore, the team points to the importance of further studies to better understand the evolutionary responses of bees to urbanisation, information that can help improve urban planning.
-end-
The work was funded by the Deutsche Forschungsgemeinschaft (German Research Foundation, DFG) via iDiv.

Martin-Luther-Universität Halle-Wittenberg

Related Bumblebees Articles:

Bumblebees benefit from faba bean cultivation
About one third of payments received by farmers are linked to 'greening measures' to promote biodiversity.
Does city life make bumblebees larger?
Does urbanisation drive bumblebee evolution? A new study by Martin Luther University Halle-Wittenberg (MLU) and the German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig provides an initial indication of this.
Researchers look for answers as to why western bumblebees are declining
The decline of the Western bumblebee is likely not limited to one culprit but, instead, due to several factors that interact such as pesticides, pathogens, climate change and habitat loss.
Bumblebees speed up flowering
When pollen is in short supply, bumblebees damage plant leaves in a way that accelerates flower production, as an ETH research team headed up by Consuelo De Moraes and Mark Mescher has demonstrated.
When plant pollen scarce, bumblebees biting leaves causes flowers to bloom early
Facing a scarcity of pollen, bumblebees will nibble on the leaves of flowerless plants, causing intentional damage in such a way that accelerates the production of flowers, according to a new study, which reports on a previously unknown behavior of bumblebees.
Pollinator-friendly flowers planted along with crops aid bumblebees
A new study reported this week by evolutionary ecologist Lynn Adler at the University of Massachusetts Amherst and Rebecca Irwin of North Carolina State University, with others, suggests that flower strips -- rows of pollinator-friendly flowers planted with crops -- offer benefits for common Eastern bumblebee (Bombus impatiens) colony reproduction, but some plants do increase pathogen infection risk.
Bumblebees aversion to pumpkin pollen may help plants thrive
Cornell University researchers have found that squash and pumpkin pollen have physical, nutritional and chemical defense qualities that are harmful to bumblebees.
Sugar-poor diets wreak havoc on bumblebee queens' health
UC Riverside study shows that without adequate sugar, a bumblebee queen's fat body, which functions like a human liver, does not correctly produce enzymes required for healthy metabolism and detoxification from pesticides.
Bumblebees can experience an object using one sense and later recognize it using another
Researchers at Queen Mary University of London and Macquarie University in Sydney have published new work in the journal Science showing that bumblebees can find objects in the dark they've only seen before.
Bumblebees recognize objects through sight and touch, a complex cognitive feat
Demonstrating an unprecedented degree of cognitive complexity in an insect, researchers report that bumblebees are capable of recognizing objects across senses.
More Bumblebees News and Bumblebees Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: The Power Of Spaces
How do spaces shape the human experience? In what ways do our rooms, homes, and buildings give us meaning and purpose? This hour, TED speakers explore the power of the spaces we make and inhabit. Guests include architect Michael Murphy, musician David Byrne, artist Es Devlin, and architect Siamak Hariri.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

What If?
There's plenty of speculation about what Donald Trump might do in the wake of the election. Would he dispute the results if he loses? Would he simply refuse to leave office, or even try to use the military to maintain control? Last summer, Rosa Brooks got together a team of experts and political operatives from both sides of the aisle to ask a slightly different question. Rather than arguing about whether he'd do those things, they dug into what exactly would happen if he did. Part war game part choose your own adventure, Rosa's Transition Integrity Project doesn't give us any predictions, and it isn't a referendum on Trump. Instead, it's a deeply illuminating stress test on our laws, our institutions, and on the commitment to democracy written into the constitution. This episode was reported by Bethel Habte, with help from Tracie Hunte, and produced by Bethel Habte. Jeremy Bloom provided original music. Support Radiolab by becoming a member today at Radiolab.org/donate.     You can read The Transition Integrity Project's report here.