Stories tagged monarchs

Want to help track monarchs? The Minnesota Zoo is offering visitors the chance to participate in a monarch tagging project. (Data from tagged monarchs helps scientists learn about their amazing migration.)

August 30, 4 - 5 p.m.
September 6, 4 -5 p.m.
(Dates are subject to change depending on the weather.)

Cost is $10 per person. Children under 10 should be accompanied by an adult. Call 952.431.9273 to make a reservation.

May
17
2006

Monarch butterfly: Courtesy Matt Stratton
Monarch butterfly: Courtesy Matt Stratton

The number of butterflies migrating through California has dropped to a forty year low, according to researchers at the University of California, Davis. One-half of the usual species of butterflies have not appeared this season, and other species have been observed in very low numbers. Climate change related to global warming and habitat destruction may be the cause.

Global warming is the increase in the Earth’s average temperature over recent decades primarily attributable to human activities.

Habitat destruction is a change in land use in which one habitat is replaced with another. The plants and animals which previously used the site are destroyed or displaced in the process.

A mild winter in Northern California has caused many species to not end their winter dormancy at the right time. This means that many butterflies emerged too late in the season. The proper climate for breeding was disrupted by a wet spring.

In Southern California, an unusually dry desert left little food for caterpillars of some species to feed on. A late snow in the Sierra Nevada may have killed many insects used for food.

Some species of butterflies that breed several times a year may rebound from these events, but for other species the effects may be devastating for up to a decade.

Read the original press release here.

May
05
2005

Every winter Monarch butterflies head south to Mexico to avoid cold temperatures.

monarch butterfly on a branch
Want to learn more about Monarchs and other butterflies? Visit the Science Museum's Monarchs and Migration website

But how in the world do they know how to get there? Well, they don't follow Highway 35, that's for sure. It turns out that monarchs can detect the sun's ultraviolet (UV) rays even when it's cloudy out. (UV rays are the part of sunlight that causes sunburn.)

Up until now we didn't know how butterflies used this UV information to fly south. Researchers led by Steven Reppert at the University of Massachusetts Medical School ran some monarchs through a flight simulator and discovered their secrets. It turns out that monarchs' eyes are very sensitive to UV light. They synch this UV information up with a natural clock in their brain. By combining these two bits of information, monarchs are able to determine the angle of the sun and always head due south. Sailors used a similar method (a sextant) to navigate around the world before the invention of compasses. Monarchs can do the trick all by themselves, though.

Do you think you could walk due south, from Minnesota to Mexico even on a cloudy day?

Some tagged monarchs have travelled more than 265 miles in a single day! Not bad for an insect...

Journey North and Monarchs in the Classroom also have cool websites (complete with projects and "Citizen Science" opportunities) about the annual Monarch butterfly migration.