The Nature Writers of Texas

The best nature writing from the newspaper, magazine, blog and book authors of the Lone Star State . . .

Saturday, December 08, 2007


Where are the monarchs?
by Carol Cullar, as published in the Eagle Pass News Guide

Remember those rtd math problems in junior high? Those problems involved the speed of a train headed in one direction and a car traveling at a different speed headed toward an intersection with that train. We had to figure out if they would ever collide. It was a matter of rate, time, and distance.

That’s the same problem facing entomologists and hundreds of monarch butterfly enthusiasts across the state today. We’ve gotten some of the information: in Rule, some five hundred miles north of here, Melody Townsend reported that they had hundreds of monarchs the night of October 3rd. Thousands of monarchs showed up in the trees at Mary Basinger’s house in Post, Texas, on the 5th. We’ve begun to see that train’s light at the other end of the tunnel.

One reassuring fact is this: we know it’s going to happen. Eagle Pass and Maverick County are more or less stalled right in the middle of the tracks as it were. Last year the monarchs exploded into our presence on the 15th and 16th of October, filling the trees all over town. Previous years they have arrived as early as the 9th. We can generally expect them somewhere around the 12th. So, heads up, Eagle Pass. Multiple forces of nature are about to collide right above our heads and fill the sky with “debris” for days and weeks!

Some are content to just sit back and observe the majesty of this annual phenomenon. Others of us really need to know how fast a monarch flies, how many hours a day it travels, and what factors determine where large clusters of the delightful and harmless creature will form for the night.

As in past years, Maverick County will be visited by researchers and film crews with tight shooting schedules, air tickets to purchase, cars to rent, and motel reservations to make. They want to know NOW.

The Rio Bravo Nature Center will need the public’s help again this year in locating monarch concentrations around town. Please, call us and leave your name, location, and phone number at 830-773-1836.

Milam Productions (Kentucky) is tentatively planning on arriving and filming on the 18th and 19th. It would be wonderful if we already had some sites to take them to.

Researchers from the University of Minnesota will arrive on October 17th to collect ongoing research data that the Nature Center has assisted with for the past six years.

So we really need to know all that rate, time, and distance information for the flutter-by monarch. Dr. Orly (Chip) Taylor of the University of Kansas established Monarch Watch fifteen years ago. Since its inception, more than 100,000 students, teachers, and citizen scientists have joined to assist annually with data collection and migration research. The Monarch Watch tagging program has added tremendously to our basic understanding of the amazing nature of the monarch migration. Fifteen years of affixing a small tag to thousands of monarch wings each year has indicated that monarchs usually fly about twenty-five miles a day.

Thousands of observers across the eastern half of the U. S. have helped refine that basic data. Monarchs tend to stall out and wait for blustery southern winds to pass their location. Sometimes they find a particularly attractive field of wildflowers and hang about nectaring for days, waiting for ideal conditions in the form of a cool front and a brisk north wind to help them on their way.

It just makes sense to get a boost from fall fronts. Monarchs doing so have been carried more than 300 miles in just three days. How do we know that? Some years ago after a front passed Monarch Watchers in Arkansas recovered a monarch tagged in Illinois three days earlier.

As they migrate south, monarchs are intent on adding to their body fat, much as, prior to hibernation, bears in Alaska glut themselves on salmon to prepare for the long winter. Monarchs are dependent on wildflowers in fields and yards and along roadsides as they journey south toward the “icebox” in Mexico’s Transvolcanicos Mountains.

Observers report some of the fattest monarchs on record as a result of the heavy summer rains experienced in the Central States this summer. Lots of food sources have made for a bumper crop of monarchs this summer. It’s not been too hot, nor too cold. It’s been . . . (need I say?) . . . just right!

What we have discovered, then, is that it’s all connected. The weather, the summer rainfall, and wildflower conditions in Central Texas, all contribute to a successful migration and have for probably the last ten thousand years.

Four hundred miles from Post to Eagle Pass at 25 to 50 miles a day? What is it, class? Somewhere between eight and sixteen more days. And if we get a cold front blowing out of Colorado during that time, then we can begin to look for monarchs in large numbers somewhere around the 13th at the earliest. Most likely the 16th or 17th. we should keep our eyes on the sky and the trees and the wildflowers along the roadsides. It should be spectacular!

0 Comments:

Post a Comment

<< Home