Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Emory study finds monarch health tied to migration

02.03.2005


Monarch butterflies in eastern North America have one of the longest migrations of any species, with a survival-of-the-fittest trek that can take them thousands of miles from Canada to Central Mexico. A new Emory University study has found that these journeys may be the key to maintaining healthy monarch populations at a time when habitat loss and other environmental issues could curb the ability of the butterflies to make the trip.



Emory researchers discovered that monarch butterflies infected with a protozoan parasite flew slower, tired faster and had to expend more energy flying than healthy monarchs. These results, published in the March issue of Ecology Letters, may explain why parasite burdens are much lower in migratory monarch populations compared to year-round residents -- an effect that possibly occurs in other migratory species as well, explains Sonia Altizer, lead researcher of the study and an assistant professor of environmental studies at Emory.

"We know that several species of birds, insects and other animals undergo two-way migrations of several thousand miles or longer. These journeys can be thought of as animals essentially running a marathon every fall and spring. So if animals are infected with parasites, this would be like a distance runner trying to run a marathon with the flu. In this case, parasitized animals will drop out of the race, and across the whole population, prevalence of disease will decline," Altizer says.


However, monarch migration in eastern North America is threatened by several environment factors such as habitat loss at wintering sites, climate warming trends and an increase of tropical milkweed species in milder climates. These dynamics could ultimately cause large migratory populations to be replaced with smaller remnants that stay put and breed year-round, she says.

"The results of our study add one more reason to protect monarch migration east of the Rockies. If this migration collapses due to climate warming, habitat loss, pesticide use or other reasons, we probably won’t lose monarchs as a species, but we’d be left with remnant, nonmigratory populations that are heavily infected with parasites, which could have several negative effects, from higher mortality rates, smaller body sizes and deformities, to more virulent strains of the parasite," Altizer says.

Altizer’s experiments, conducted with graduate student Catherine Bradley, showed that parasitized monarch butterflies had 10-20 percent lower flight ability while on the "butterfly treadmill," and that the parasite affected their ability to fly long distances. Although the infected monarchs looked the same, weighed the same and had nearly identical survival rates to adulthood when they were not migrating, the flight trials in the laboratory essentially "unmasked" an effect of the parasite that normally would have been hidden. "The experiment demonstrates that seemingly small effects of parasites on their hosts can have a larger impact when combined with the stresses of migration," Altizer says.

Beverly Cox Clark | EurekAlert!
Further information:
http://www.emory.edu

More articles from Life Sciences:

nachricht First line of defence against influenza further decoded
21.02.2018 | Helmholtz-Zentrum für Infektionsforschung

nachricht Helping in spite of risk: Ants perform risk-averse sanitary care of infectious nest mates
21.02.2018 | Institute of Science and Technology Austria

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

MEMS chips get metatlenses

21.02.2018 | Physics and Astronomy

International team publishes roadmap to enhance radioresistance for space colonization

21.02.2018 | Physics and Astronomy

World's first solar fuels reactor for night passes test

21.02.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>