Sunday, July 26, 1998

The Monarchs will soon be roosting in Abilene again

By Ruth Addington / Guest Columnist

When are the monarchs due?

The migration usually reaches Abilene the last part of September and the first half of October. Last year a few came in August. That was followed by a truly spectacular migration that lasted almost a month.

Dr. Orley Taylor of the University of Kansas, director of the Monarch Watch, estimated the number at between 200 million and 500 million. We're fortunate our area is on a main migration route to the monarch's wintering grounds in the mountains of central Mexico.

The Abilene zoo has been taking part in a monarch tagging program since 1991. We are now assisted by several science teachers and their classes. For the past two years, Gary Musgrave of Cooper High School, has coordinated the school projects.

Last year about 1,400 monarchs were tagged and the data recorded. One of the butterflies tagged by Larry Millar, art teacher at Cooper, was captured at the wintering grounds five months and 892 miles later!

The most puzzling event of the 1997 migration took place in River Oaks in early October. One morning the owner went out and found at least 1,000 detached monarch wings on the grass under a large oak tree. The wings were cleanly, almost surgically, detached. They were brightly colored and unfrayed, showing the monarchs were in prime condition.

Two nights later Musgrave and I went back to the yard with a flashlight and watched until 11 p.m., but he saw nothing to account for the attacks. Yet the nightly destruction continued, made visible by clearing the area each day.

One suggestion was that it was caused by a flock of grackles, but monarchs are known to be sickening to birds because of the milkweed that the larvae eat. Neighbors who have lots of monarchs and also grackles report that they have never seen a grackle attack a monarch. And birds feed during the day and roost at night.

Another science teacher who heard of the strange happening watched the monarchs in his yard and saw them attacked by praying mantises and photographed the attack. They also left detached wings, and this teacher believes that is the answer to this mystery. Musgrave agrees that is the most likely explanation. We had more praying mantises than usual because of abundant fall rains.

Dr. Bill Calvert, director of the Texas Monarch Watch, said he had never known of such an occurrence except in the wintering grounds in Mexico where the birds have adapted to the poisonous monarchs.

I also called the Urquharts in Toronto. Dr. Fred Urquhart and his wife, Norah, have been studying and tagging monarchs since 1938. His tagging work led to his discovery in 1976 of their wintering grounds in Mexico. He has been considered the world's leading authority on monarchs for decades. The Urquharts reported they have never known of such an occurrence except in the wintering grounds. It seems we witnessed a once-in-a-lifetime event that happened in one tree in one yard in Abilene.

Dr. Taylor reports El Nino caused trouble in the wintering grounds in Mexico. It was drier and colder than usual, and apparently millions of monarchs were frozen. He thinks, however, we could still have a normal migration this fall if the migrants that did return are able to find ample nectar plants to feed on and milkweed to lay their eggs on this summer.

The Abilene zoo has 1,500 monarch tags ready for distribution to the teachers and classes that take part in the exciting and mysterious monarch experience we are favored with each year. A tree covered with a thousand roosting orange and black butterflies is a stunning sight that is never forgotten.

Ruth Addington, an Abilene Zoo board member, asked for an area at the zoo grounds for planting wild flowers to attract butterflies. Now the zoo is designated as an official Monarch Sanctuary.