The City Magazine Since 1975

Chasing Rainbows

January 2018
Chasing Rainbows
WRITER: 

Feeling lucky? Aim to catch prismatic magic in Caw Caw’s winter swamp

Rainbow colors paint the swamp at Caw Caw.

The ephemeral happens every day at Caw Caw Interpretive Center, a wildlife preserve renowned for its unusual birds and blooms. But one fleeting phenomenon in particular attracts visitors each winter: a show of sunlight, cypress leaves, and still water that illuminates the swamp with a rainbow of pastel hues.

“It’s really a simple thing,” said Caw Caw facility manager Thomas Thornton of the display. As bald cypresses drop their leaves in the fall, the decomposing matter releases tannins that form a film on the surface of the swamp’s dark water. “When the sun hits at the proper angle, it has a prismatic effect,” Thornton says. “It’s difficult to predict but very dramatic when all the variables are in place.”

Those variables seem best aligned on bright winter mornings, when the intensity and angle of the sun strengthen the rainbow colors. The effect has been reported across other Southeastern cypress swamps, but Caw Caw may be your best bet for witnessing the magic in the Charleston area.

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Photograph by Weatherly Meadors