It is one of the most amazing migrations in all of the world, not least because the animal making the 3,000-mile journey weighs half a gram and North Texans often see the ancient journey from their back yards and gardens.

But, with only isolated sightings, the last few weeks proved disappointing for monarch butterfly watchers in virtually all of Texas. Normally the butterflies' migration from the Red River to the Rio Grande Valley is hailed as one of autumn's great marvels.

"I've seen probably four monarchs in the last three weeks," lamented Michael Warriner, an invertebrate biologist with the Texas Parks & Wildlife Department in Austin.

The likely reason lies in the merciless drought, which dramatically reduced the butterflies' main food source as they moved south for the winter. The shortage of nectar from blooming plants, plus thousands of acres scorched by wildfires, likely meant that the migratory pattern was dispersed over a much greater area as the butterflies sought food. Based on informal reporting by residents, the overall count appears to be below average.

"The pattern was widespread, all the way from the I-35 corridor to the Davis Mountains," said Mike Quinn, an entomologist who is coordinator of Texas Monarch Watch, part of a monarch educational and research organization based in Kansas. "They usually aren't that widely distributed."

The monarch butterfly, like Pacific salmon and the gray whale, makes a jaw-dropping annual migration that must be mysteriously plugged into its genetic makeup, made all the more remarkable because no single monarch makes the entire round-trip journey. Their offspring and their offspring's offspring know what to do and where to go on their own.

The monarch has an outsize reputation among nature lovers in the Plains states.

Grapevine, for example, has an annual festival -- the Butterfly Flutterby -- to celebrate the migration.

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