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Photo © Keith Williams
Photo © Frank Colver

A Bed of Thorns

When Frank Colver decided to relocate an old Say’s Phoebe nest from an unstable spot to a newly constructed nesting shelf, he jumped in pain and surprise when the nest pricked his bare hands.The exterior of the nest was lined with tiny, barbed spines from a Gander’s cholla cactus. 

During the breeding season, cacti fulfill an important ecological role for desert-dwelling birds. Birds such as Gila Woodpeckers, Gilded Flickers, and Elf Owls create or utilize existing nest cavities, while other birds such as Harris’s Hawks build nesting platforms atop tall, sturdy cacti. Curve-billed Thrashers, Cactus Wrens, and Greater Roadrunners build their nests deep within a cactus’ thorny and protective embrace. 

In most cases, birds place their nests in a cactus rather than collecting thorns for their nests. In fact, we believe that Frank’s discovery is not only odd for Say’s Phoebes, but it is also uncommon for birds across the U.S. While thrashers are also known to include thorny twigs in their nests, we haven’t seen any examples with cactus spines.

Frank’s discovery is a mystery. Did the phoebe select the barbed spines to help hold the nest together? Were the spines meant to create a protective fortress around the soft interior of the nest? Or were they just a convenient source of nest material? Moreover, have other NestWatchers discovered nests that had spines incorporated as nesting material? If you have discovered a literal bed of thorns, we would love to know. Share your photos or email NestWatch

Cornell Lab of Ornithology

Cornell Lab of Ornithology