Featured Research

from universities, journals, and other organizations

How bumblebees tackle the traveling salesman problem

Date:
June 29, 2011
Source:
Queen Mary, University of London
Summary:
New research reveals how bumblebees effectively plan their route between the most rewarding flowers while traveling the shortest distances.

An artificial flower is being visited by a bumblebee (Bombus terrestris) worker. The bee obtains a small sugar solution reward when it visits the flower. The flower can be refilled by remote control so the behaviour of bees was not disturbed during the experiment.
Credit: Mathieu Lihoreau

It is a mathematical puzzle which has vexed academics and travelling salesmen alike, but new research from Queen Mary, University of London's School of Biological and Chemical Sciences, reveals how bumblebees effectively plan their route between the most rewarding flowers while travelling the shortest distances.

The research, led by Dr Mathieu Lihoreau and published in the British Ecological Society's Functional Ecology, explored the movement of bumblebees, Bombus terrestris, as they collected nectar from five artificial flowers varying in reward value.

"Animals which forage on resources that are fixed in space and replenish over time, such as flowers which refill with nectar, often visit these resources in repeatable sequences called trap-lines," said Dr Lihoreau, "While trap-lining is a common foraging strategy found in bees, birds and primates we still know very little about how animals attempt to optimise the routes they travel."

Research into optimising routes based on distance and the size of potential rewards is reminiscent of the well known Travelling Salesman problem in mathematics, which was first formulated in 1930, but remains one of the most intensively studied problems in optimisation.

"The Travelling Salesman must find the shortest route that allows him to visit all locations on his route," explained co-author Dr Nigel Raine, "Computers solve it by comparing the length of all possible routes and choosing the shortest. However, bees solve simple versions of it without computer assistance using a brain the size of grass seed."

The team set up a bee nest-box, marking each bumblebee with numbered tags to follow their behaviour when allowed to visit five artificial flowers which were arranged in a regular pentagon.

"When the flowers all contain the same amount of nectar bees learned to fly the shortest route to visit them all," said Dr Lihoreau. "However, by making one flower much more rewarding than the rest we forced the bees to decide between following the shortest route or visiting the most rewarding flower first."

In a feat of spatial judgement the bees decided that if visiting the high reward flower added only a small increase in travel distance, they switched to visiting it first. However, when visiting the high reward added a substantial increase in travel distance they did not visit it first.

The results revealed a trade-off between either prioritising visits to high reward flowers or flying the shortest possible route. Individual bees attempted to optimise both travel distance and nectar intake as they gained experience of the flowers.

"We have demonstrated that bumblebees make a clear trade-off between minimising travel distance and prioritising high rewards when considering routes with multiple locations," concluded co-author Professor Lars Chittka. "These results provide the first evidence that animals use a combined memory of both the location and profitability of locations when making complex routing decisions, giving us a new insight into the spatial strategies of trap-lining animals."


Story Source:

The above story is based on materials provided by Queen Mary, University of London. Note: Materials may be edited for content and length.


Journal Reference:

  1. Mathieu Lihoreau, Lars Chittka, Nigel E. Raine. Trade-off between travel distance and prioritization of high-reward sites in traplining bumblebees. Functional Ecology, 2011; DOI: 10.1111/j.1365-2435.2011.01881.x

Cite This Page:

Queen Mary, University of London. "How bumblebees tackle the traveling salesman problem." ScienceDaily. ScienceDaily, 29 June 2011. <www.sciencedaily.com/releases/2011/06/110628191339.htm>.
Queen Mary, University of London. (2011, June 29). How bumblebees tackle the traveling salesman problem. ScienceDaily. Retrieved August 23, 2014 from www.sciencedaily.com/releases/2011/06/110628191339.htm
Queen Mary, University of London. "How bumblebees tackle the traveling salesman problem." ScienceDaily. www.sciencedaily.com/releases/2011/06/110628191339.htm (accessed August 23, 2014).

Share This




More Plants & Animals News

Saturday, August 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Endangered Red Wolves Face Uncertain Future

Endangered Red Wolves Face Uncertain Future

AP (Aug. 22, 2014) A federal judge temporarily banned coyote hunting to save endangered red wolves, but local hunters say that the wolf preservation program does more harm than good. Meanwhile federal officials are reviewing its wolf program in North Carolina. (Aug. 22) Video provided by AP
Powered by NewsLook.com
Farm Resurgence Grows With Younger Crowd

Farm Resurgence Grows With Younger Crowd

AP (Aug. 22, 2014) New England farms are seeing a surge in younger farm hands as the 'buy local' food movement grows across the country. (Aug. 22) Video provided by AP
Powered by NewsLook.com
Drug Used To Treat 'Ebola's Cousin' Shows Promise

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Newsy (Aug. 21, 2014) An experimental drug used to treat Marburg virus in rhesus monkeys could give new insight into a similar treatment for Ebola. Video provided by Newsy
Powered by NewsLook.com
Terrifying City-Dwelling Spiders Are Bigger And More Fertile

Terrifying City-Dwelling Spiders Are Bigger And More Fertile

Newsy (Aug. 21, 2014) According to a new study, spiders that live in cities are bigger, fatter and multiply faster. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins