The North American monarch butterfly’s amazing migration, travelling thousands of miles each year from its wintering grounds in Mexico to as far north as the Great Lakes of Canada and back, is done without any internal maps, a study has found. The Independent reports
Scientists have shown that the annual migration of the monarch butterfly is achieved with just an in-built “compass” – based on the position of the sun – which tells the insect which direction it should fly at the appropriate time of the year.
Researchers have long speculated on how the insect, which weighs about half a gram, is able to make the return journey to the mountain forests of Mexico for winter, especially as those born in late summer, would not have made the journey before.
Experts thought they used an internal, genetically encoded “map” to locate their position, as well as a built-in compass to tell them where to fly. But now a study has shown that the butterflies manage with just a compass alone.
“To be a true navigator, you need both a compass and a map. We’ve known for some time that monarchs use external cues, such as the sun and magnetic field, as a built-in compass that can indicate their latitude. But having an internal map requires knowledge of both latitude and longitude,” said butterfly expert Professor Ryan Norris of the University of Guelph in Ontario. “Given the challenge of this migratory journey and the fact that these insects weigh less than a gram, it is a remarkably simple system they use to travel thousands of kilometres to a site they have never seen,” Professor Norris said.
The scientists took monarch butterflies from the Ontario region of eastern Canada and tested their migratory flight patterns in experiments set up 2,500km away to the west in Calgary. They found that the monarch continued to try to fly in the same direction and did not compensate for the geographic displacement.
“The monarchs we tested in Guelph flew south-west, in the general direction of Mexico. When we tested them in Calgary, they flew in the same general direction as if they were in Ontario, suggesting they did not know they had been displaced 2,500km,” said Rachel Derbyshire, who carried out the work published in the Proceeding of the National Academy of Sciences.
It is likely the butterflies also use landmarks, such as mountain ranges, to help them find their way, and possibly scent when they are near to their final goal, the oyamel trees of the Mexican highlands where they clump together in their thousand to spend the winter season.
- No map, no problems for monarchs (esciencenews.com)
- Monarch butterflies navigate with compass but no map (nature.com)
- Where Have All the Monarch Butterflies Gone? (thefunlifeofsophia.wordpress.com)
- Monarch butterflies navigate with compass but no map (richarddawkins.net)
As the debate continues about whether we should focus on pandas as single species, not habitats, or just creatures where survival is likely – see my resource page – - China Daily reports on another exchange. Note that in the case of Edinburgh Zoos pandas, Scotland had to pick up the tab!
WHAT DO YOU THINK? Should panda exchanges continue? Are they helpful in raising awareness for conservation or just a tourism magnet? Comment here below or at my twitter.
The Chinese Association of Zoological Gardens (CAZG) Saturday signed the deal with twoCanadian zoos in Chongqing, a municipality in Southwest China.
The panda pair, both around five years old, will stay in the Toronto and Calgary zoos for five yearseach after they arrive in Canada early next year, according to the agreement.
The male panda, named ”Er Shun,” is from a zoo in Chongqing and the female - “Ji Li“ lives in theChengdu Research Base of Giant Panda Breeding, home of over 100 pandas in the neighboringSichuan province.
Giant pandas are the world’s most endangered species. About 300 of the animals have been bredin captivity and 1,596 others live in the wild, mostly in Sichuan.
Canadian Prime Minister Stephen Harper witnessed Saturday’s signing ceremony during his visit toChongqing.
“They will be the first pair of pandas to visit Canada since the 1980s,” said Harper.
In his second visit to China, Harper came to Beijing on Tuesday for a five-day trip as a guest ofPremier Wen Jiabao. The Canadian prime minister met and held talks with top Chinese leadersand witnessed the signing of several bilateral agreements regarding cooperation in trade,technology, education, forestry, energy and agriculture.
Harper also visited China’s southern economic hub of Guangdong province before heading toChongqing.
- Pandas Coming To Toronto, Calgary (huffingtonpost.ca)
- Chinese pandas heading to zoos in Toronto, Calgary (vancouversun.com)
- Pandas heading to zoos in Toronto, Calgary (canada.com)
- Pandas heading to zoos in Calgary, Toronto: Gallery (calgaryherald.com)
- Calgary Zoo, tourism officials hail news of Chinese panda loan – Calgary Herald (calgaryherald.com)
- Stephen Harper secures pandas for Toronto, Calgary during China mission (news.nationalpost.com)
- Harper to talk investment, pandas during Chinese visit (news.nationalpost.com)
- Pandas coming to Calgary, Toronto (cbc.ca)
- China blocks Canadian television footage of Harper (cbc.ca)