How migrating butterflies use body clocks to find their way

A A A

The spectacular migration of the monarch butterfly, which covers a 2,000-mile round trip in a year, uses an inbuilt precision clock that enables the insect to use the sun as a compass, a study has found.

An internal biological clock that times the 24-hour cycle of night and day allows the monarch butterfly to calculate its direction of flight when migrating either north or south, depending on the time of the year, scientists have discovered.

Monarch butterflies are famous for the journey they make each spring from their winter roosting sites in the mountain pine trees of Mexico to as far as the US-Canadian border and back again in autumn an unparalleled migratory feat for such as small creature. As the monarchs fly north in spring they breed several times during their summer journey. Four or five generations later, their offspring make the long journey home again, often landing in the same Mexican valley and even on the same tree that their great, great grandparents left the previous winter.

Scientists have known for years that the monarchs use the sun as a compass to guide them on their journey, and as a calendar for telling them when to begin the return journey to Mexico. But a compass based on the sun's moving position in the sky would not work unless the insects also have an accurate clock to tell them the time of day.

No one had been able to locate this internal timepiece, until now. A study by Steven Reppert, professor of neurobiology at the University of Massachusetts Medical School, has identified the key gene in the monarch butterfly that acts as a biological clock for estimating the 24-hour cycle of the circadian rhythm.

Professor Reppert said that the gene was responsible for a light-sensitive protein called cryptochrome (CRY) which counts the passing hours of each day, and also communicates the information to the monarch's inbuilt solar compass for the insect to calculate its correct direction of flight.

It is the second CRY gene to be found in insects. The first, CRY1, was discovered in drosophila fruit flies but the monarch's gene is sufficiently different to warrant a distinctive name, CRY2, Professor Reppert said. "This is a very interesting realignment of how one thinks about insect-clock models. There was no reason to suspect the butterfly clock would be different," he said.

"What we have in the butterfly is an astounding clock mechanism, one that is more similar to our own circadian clock and less similar to the clock of a fly," he said. "We have still to understand how the tiny brain of the monarch butterfly, which is no bigger than the head of a ballpoint pen, can arrange information about time and space that leads it to carry out the appropriate flight behaviour," Professor Reppert told the online journal Public Library of Science.

News
peopleFrankie Boyle responds to referendum result in characteristically offensive style
News
news
Life and Style
Couples have been having sex less in 2014, according to a new survey
life
New Articles
i100... with this review
PROMOTED VIDEO
Have you tried new the Independent Digital Edition apps?
Voices
Holly's review of Peterborough's Pizza Express quickly went viral on social media
Sport
footballTim Sherwood: This might be th match to wake up Manchester City
Arts and Entertainment
musicHow female vocalists are now writing their own hits
New Articles
i100
News
news
Arts and Entertainment
musicBiographer Hunter Davies has collected nearly a hundred original manuscripts
News
Blahnik says: 'I think I understand the English more than they do themselves'
people
Arts and Entertainment
Michelle Dockery as Lady Mary Crawley in Downton Abbey
TVInside Downton Abbey series 5
Life and Style
The term 'normcore' was given the oxygen of publicity by New York magazine during the autumn/winter shows in Paris in February
fashionWhen is a trend a non-trend? When it's Normcore, since you ask
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
iJobs Job Widget
iJobs General

Marketing Manager - Leicestershire - £35,000

£30000 - £35000 per annum: Ashdown Group: Marketing Manager (CIM, B2B, MS Offi...

Marketing Executive (B2B and B2C) - Rugby, Warwickshire

£22000 - £25000 per annum: Ashdown Group: A highly successful organisation wit...

SEN Coordinator + Teacher (SENCO)

£1 per day: Randstad Education Leeds: Job Purpose To work closely with the he...

Research Manager - Quantitative/Qualitative

£32000 - £42000 Per Annum: Clearwater People Solutions Ltd: Our client is curr...

Day In a Page

Scottish referendum: The Yes vote was the love that dared speak its name, but it was not to be

Despite the result, this is the end of the status quo

Boyd Tonkin on the fall-out from the Scottish referendum
Manolo Blahnik: The high priest of heels talks flats, Englishness, and why he loves Mary Beard

Manolo Blahnik: Flats, Englishness, and Mary Beard

The shoe designer who has been dubbed 'the patron saint of the stiletto'
The Beatles biographer reveals exclusive original manuscripts of some of the best pop songs ever written

Scrambled eggs and LSD

Behind The Beatles' lyrics - thanks to Hunter Davis's original manuscript copies
'Normcore' fashion: Blending in is the new standing out in latest catwalk non-trend

'Normcore': Blending in is the new standing out

Just when fashion was in grave danger of running out of trends, it only went and invented the non-trend. Rebecca Gonsalves investigates
Dance’s new leading ladies fight back: How female vocalists are now writing their own hits

New leading ladies of dance fight back

How female vocalists are now writing their own hits
Mystery of the Ground Zero wedding photo

A shot in the dark

Mystery of the wedding photo from Ground Zero
His life, the universe and everything

His life, the universe and everything

New biography sheds light on comic genius of Douglas Adams
Save us from small screen superheroes

Save us from small screen superheroes

Shows like Agents of S.H.I.E.L.D are little more than marketing tools
Reach for the skies

Reach for the skies

From pools to football pitches, rooftop living is looking up
These are the 12 best hotel spas in the UK

12 best hotel spas in the UK

Some hotels go all out on facilities; others stand out for the sheer quality of treatments
These Iranian-controlled Shia militias used to specialise in killing American soldiers. Now they are fighting Isis, backed up by US airstrikes

Widespread fear of Isis is producing strange bedfellows

Iranian-controlled Shia militias that used to kill American soldiers are now fighting Isis, helped by US airstrikes
Topshop goes part Athena poster, part last spring Prada

Topshop goes part Athena poster, part last spring Prada

Shoppers don't come to Topshop for the unique
How to make a Lego masterpiece

How to make a Lego masterpiece

Toy breaks out of the nursery and heads for the gallery
Meet the ‘Endies’ – city dwellers who are too poor to have fun

Meet the ‘Endies’ – city dwellers who are too poor to have fun

Urbanites are cursed with an acronym pointing to Employed but No Disposable Income or Savings
Paisley’s decision to make peace with IRA enemies might remind the Arabs of Sadat

Ian Paisley’s decision to make peace with his IRA enemies

His Save Ulster from Sodomy campaign would surely have been supported by many a Sunni imam