OKLAHOMA CITY (AP) _ Thousands of monarch butterflies heading south for the winter spent the last few weeks refueling on Oklahoma nectar.
The brilliantly colored insects _ Danaus plexippus _ flutter along central Oklahoma's monarch ``flyway'' each year beginning in September.
Neil Garrison, a naturalist at Oklahoma City's Martin Park Nature Center, observes them as they pass through.
He said the butterflies may continue on their southern journey by this weekend, after a cold front moved into Oklahoma Friday. The monarchs take advantage of the north wind and take off, he said.
``They'll disappear in 15 minutes,'' Garrison said.
About 100,000 Americans help an organization called Monarch Watch track the butterflies' route. The group, founded by a University of Kansas entomologist, tracks monarch movements to understand their journey.
Volunteers tag the delicate creatures with a coded adhesive spot the size of a pinky fingernail right on their most delicate parts _ their wings.
``You have to have delicate fingertips,'' said David Walker, senior naturalist for the Oklahoma City Zoo.
One butterfly tagged this year, called ZH-768, made it from at least Oklahoma City to El Rosario, Mexico _ a distance of 1,110 miles.
``It's kind of neat,'' Walker said.
Monarchs are ``an ideal research animal,'' said Bob Melton, science curriculum coordinator for Putnam City schools. They are one of the few migrating animals you can catch easily, he said.
Putnam City students are lurking in parks with nets this fall, planning to tag 4,000 monarchs. They record information about the insects, such as where and when they were found and what they were doing.
The information goes into a database for Monarch Watch.
When a tagged monarch is found, the numbers on it reveal how far it has traveled.
Four butterflies tagged at the zoo in its five years of tagging have turned up in Mexico. Putnam City students every year tag monarchs that turn up in Mexico.
Millions of monarchs end up clustered in fir trees on a few acres high in the mountains near Mexico City.
``It's all innate. It's inside their heads,'' Garrison said. ``It's pretty fascinating stuff.''