Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


UMMS scientists show that monarch butterflies employ a magnetic compass during migration


Study published in Nature Communications finds inclination compass in monarchs responds to UVA light

Each fall millions of monarch butterflies use a sophisticated navigation system to transverse 2,000 miles from breeding sites across the eastern United States to an overwintering habitat in specific groves of fir trees in central Mexico.

Scientists at the University of Massachusetts Medical School and Worcester Polytechnic Institute have identified a new component of this complex system. They reported in Nature Communications that monarchs use a light-dependent, inclination magnetic compass to help them orient southward during migration.

"Taken as a whole, our study reveals another fascinating aspect of the monarch butterfly migratory behavior," said senior study author Steven Reppert, MD, the Higgins Family Professor of Neuroscience and distinguished professor of neurobiology at UMass Medical School.

"Greater knowledge of the mechanisms underlying the fall migration may well aid in its preservation, currently threatened by climate change and by the continuing loss of milkweed and overwintering habitats. A new vulnerability to now consider is the potential disruption of the magnetic compass in the monarchs by human-induced electromagnetic noise, which can also affect geomagnetic orientation in migratory birds."

Co-author Robert Gegear, PhD, assistant professor of biology and biotechnology at WPI, explained, "Our study shows that monarchs use a sophisticated magnetic inclination compass system for navigation similar to that used by much larger-brained migratory vertebrates such as birds and sea turtles."

Monarchs use a time-compensated sun compass in their antenna to help them make their 2,000 mile migratory journey to overwintering sites. During the absence of daylight cues, such as under dense cloud cover, migrants have been, surprisingly, seen flying in the expected southerly direction. It's been hypothesized that monarchs use geomagnetic cues to help navigate when day light cues are unavailable to them during migration.

Previous attempts by scientists to isolate use of an internal inclination compass in monarchs have yielded conflicting or unconvincing results. These studies, however, may not have accounted for the possibility that the magnetic compass was influenced by ultraviolet light that can penetrate cloud cover.

Given the ability of monarch cryptochromes (CRY), a class of proteins that are sensitive to ultraviolet A/blue light, to restore a light-dependent magnetic response in CRY-deficient Drosophila, Reppert and colleagues suspected that monarchs also possessed a light-dependent magnetic compass.

Using flight simulators equipped with artificial magnetic fields, Patrick Guerra, PhD, a postdoctoral fellow in the Reppert lab, examined monarch flight behavior under diffuse white light conditions. He found that tethered monarchs in the simulators oriented themselves in a southerly direction. Further tests in the simulator revealed that the butterflies used the inclination angle of Earth's magnetic field to guide their movement. Reversing the direction of the inclination caused the monarchs to orient in the opposite direction, to the north instead of the south.

To test the light-dependence of the monarch's magnetic compass, Dr. Guerra applied a series of wavelength blocking filters to the lights in the simulator. Monarchs exposed to light only in the wavelength range above 420nm exhibited a lack of direction by flying in circles. Monarchs exposed to light in the wavelength range above 380nm showed clear signs of directional flight. These tests showed that the monarch's magnetic compass, and thus directional flight, was dependent on exposure to light wavelengths (380nm to 420nm) found in the ultraviolet A/blue light spectral range.

Together, these results provide the first demonstration that the monarch butterfly uses a light-dependent, inclination compass during its long journey. It is also the first evidence of such a navigational tool in a long-distance migratory insect.

"For migratory monarchs, the inclination compass may serve as an important back up system when daylight cues are unavailable," Guerra said. "It may also augment hand-in-hand with the time-compensated sun compass to provide orientation and directionality throughout the migration process."

The next step for Reppert and colleagues will be to evaluate the molecular and genetic mechanisms of magneto-reception in the monarch butterfly and the involvement of CRYs.


About the University of Massachusetts Medical School

The University of Massachusetts Medical School (UMMS), one of five campuses of the University system, comprises the School of Medicine, the Graduate School of Biomedical Sciences, the Graduate School of Nursing, a thriving research enterprise and an innovative public service initiative, Commonwealth Medicine. Its mission is to advance the health of the people of the commonwealth through pioneering education, research, public service and health care delivery with its clinical partner, UMass Memorial Health Care. In doing so, it has built a reputation as a world-class research institution and as a leader in primary care education. The Medical School attracts more than $240 million annually in research funding, placing it among the top 50 medical schools in the nation. In 2006, UMMS's Craig C. Mello, PhD, Howard Hughes Medical Institute Investigator and the Blais University Chair in Molecular Medicine, was awarded the Nobel Prize in Physiology or Medicine, along with colleague Andrew Z. Fire, PhD, of Stanford University, for their discoveries related to RNA interference (RNAi). The 2013 opening of the Albert Sherman Center ushered in a new era of biomedical research and education on campus. Designed to maximize collaboration across fields, the Sherman Center is home to scientists pursuing novel research in emerging scientific fields with the goal of translating new discoveries into innovative therapies for human diseases.

Jim Fessenden | Eurek Alert!
Further information:

Further reports about: Medicine butterfly monarchs ultraviolet wavelength

More articles from Life Sciences:

nachricht Supercoiled DNA is far more dynamic than the 'Watson-Crick' double helix
13.10.2015 | University of Leeds

nachricht New Oregon approach for 'nanohoops' could energize future devices
13.10.2015 | University of Oregon

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Secure data transfer thanks to a single photon

Physicists of TU Berlin and mathematicians of MATHEON are so successful that even the prestigious journal “Nature Communications” reported on their project.

Security in data transfer is an important issue, and not only since the NSA scandal. Sometimes, however, the need for speed conflicts to a certain degree with...

Im Focus: A Light Touch May Help Animals and Robots Move on Sand and Snow

Having a light touch can make a hefty difference in how well animals and robots move across challenging granular surfaces such as snow, sand and leaf litter. Research reported October 9 in the journal Bioinspiration & Biomimetics shows how the design of appendages – whether legs or wheels – affects the ability of both robots and animals to cross weak and flowing surfaces.

Using an air fluidized bed trackway filled with poppy seeds or glass spheres, researchers at the Georgia Institute of Technology systematically varied the...

Im Focus: Reliable in-line inspections of high-strength automotive body parts within seconds

Nondestructive material testing (NDT) is a fast and effective way to analyze the quality of a product during the manufacturing process. Because defective materials can lead to malfunctioning finished products, NDT is an essential quality assurance measure, especially in the manufacture of safety-critical components such as automotive B-pillars. NDT examines the quality without damaging the component or modifying the surface of the material. At this year's Blechexpo trade fair in Stuttgart, Fraunhofer IZFP will have an exhibit that demonstrates the nondestructive testing of high-strength automotive body parts using 3MA. The measurement results are available in a matter of seconds.

To minimize vehicle weight and fuel consumption while providing the highest level of crash safety, automotive bodies are reinforced with elements made from...

Im Focus: Kick-off for a new era of precision astronomy

The MICADO camera, a first light instrument for the European Extremely Large Telescope (E-ELT), has entered a new phase in the project: by agreeing to a Memorandum of Understanding, the partners in Germany, France, the Netherlands, Austria, and Italy, have all confirmed their participation. Following this milestone, the project's transition into its preliminary design phase was approved at a kick-off meeting held in Vienna. Two weeks earlier, on September 18, the consortium and the European Southern Observatory (ESO), which is building the telescope, have signed the corresponding collaboration agreement.

As the first dedicated camera for the E-ELT, MICADO will equip the giant telescope with a capability for diffraction-limited imaging at near-infrared...

Im Focus: Locusts at the wheel: University of Graz investigates collision detector inspired by insect eyes

Self-driving cars will be on our streets in the foreseeable future. In Graz, research is currently dedicated to an innovative driver assistance system that takes over control if there is a danger of collision. It was nature that inspired Dr Manfred Hartbauer from the Institute of Zoology at the University of Graz: in dangerous traffic situations, migratory locusts react around ten times faster than humans. Working together with an interdisciplinary team, Hartbauer is investigating an affordable collision detector that is equipped with artificial locust eyes and can recognise potential crashes in time, during both day and night.

Inspired by insects

All Focus news of the innovation-report >>>



Event News

EHFG 2015: Securing healthcare and sustainably strengthening healthcare systems

01.10.2015 | Event News

Conference in Brussels: Tracking and Tracing the Smallest Marine Life Forms

30.09.2015 | Event News

World Alzheimer`s Day – Professor Willnow: Clearer Insights into the Development of the Disease

17.09.2015 | Event News

Latest News

Listening to the Extragalactic Radio

13.10.2015 | Physics and Astronomy

Penn study stops vision loss in late-stage canine X-linked retinitis pigmentosa

13.10.2015 | Health and Medicine

MRCE orders Vectron Locomotives

13.10.2015 | Press release

More VideoLinks >>>