Update:
Black-Spotted Barbet (4 holders)
Nashville Zoo at Grassmere
San Antonio Zoo
San Diego Zoo
Zoo Miami
Versicolored Barbet (1 holder)
Dallas World Aquarium (glaucogularis)
Bearded Barbet (14 holders)
Birmingham Zoo
Bronx Zoo
Charles Paddock Zoo
Franklin Park Zoo
Hattiesburg Zoo
Lee Richardson Zoo
Milwaukee County Zoo
Oregon Zoo
Prospect Park Zoo
San Diego Zoo
San Diego Zoo Safari Park
Sylvan Heights Bird Park
Toledo Zoo and Aquarium
Tracy Aviary
Fire-Tufted Barbet (1 holder)
San Diego Zoo
Red-And-Yellow Barbet (12 holders)
Cincinnati Zoo and Botanical Garden
Dallas Zoo
Henry Vilas Zoo
Honolulu Zoo
Lincoln Park Zoo
Los Angeles Zoo & Botanical Garden
Oklahoma City Zoo
San Antonio Zoo
San Diego Zoo
Tautphaus Park Zoo
Topeka Zoo
Tulsa Zoo
Puerto Rican Woodpcker (1 holder)
Dallas World Aquarium
Acorn Woodpecker (3 holders)
California Living Museum (bairdi)
Dallas World Aquarium (striatipectus)
The Living Desert Zoo and Gardens (bairdi)
Gila Woodpecker (1 holder)
Utah's Hogle Zoo
Red-Bellied Woodpecker (1 holder)
Fort Worth Zoo
Downy Woodpecker (3 holders)
Akron Zoo
Bay Beach Wildlife Sanctuary
Minnesota Zoo
Hairy Woodpecker (1 holder)
Cosley Zoo
Greater Yellownape Woodpecker (1 holder)
San Diego Zoo (pierrei)
Golden-backed Woodpecker (1 holder)
Toledo Zoo and Aquarium
Pileated Woodpecker (2 holders)
Buttonwood Park Zoo
Minnesota Zoo
Northern Flicker (1 holder)
Cosley Zoo
Black-Spotted Barbet (4 holders)
Nashville Zoo at Grassmere
San Antonio Zoo
San Diego Zoo
Zoo Miami
Versicolored Barbet (1 holder)
Dallas World Aquarium (glaucogularis)
Bearded Barbet (14 holders)
Birmingham Zoo
Bronx Zoo
Charles Paddock Zoo
Franklin Park Zoo
Hattiesburg Zoo
Lee Richardson Zoo
Milwaukee County Zoo
Oregon Zoo
Prospect Park Zoo
San Diego Zoo
San Diego Zoo Safari Park
Sylvan Heights Bird Park
Toledo Zoo and Aquarium
Tracy Aviary
Fire-Tufted Barbet (1 holder)
San Diego Zoo
Red-And-Yellow Barbet (12 holders)
Cincinnati Zoo and Botanical Garden
Dallas Zoo
Henry Vilas Zoo
Honolulu Zoo
Lincoln Park Zoo
Los Angeles Zoo & Botanical Garden
Oklahoma City Zoo
San Antonio Zoo
San Diego Zoo
Tautphaus Park Zoo
Topeka Zoo
Tulsa Zoo
Puerto Rican Woodpcker (1 holder)
Dallas World Aquarium
Acorn Woodpecker (3 holders)
California Living Museum (bairdi)
Dallas World Aquarium (striatipectus)
The Living Desert Zoo and Gardens (bairdi)
Gila Woodpecker (1 holder)
Utah's Hogle Zoo
Red-Bellied Woodpecker (1 holder)
Fort Worth Zoo
Downy Woodpecker (3 holders)
Akron Zoo
Bay Beach Wildlife Sanctuary
Minnesota Zoo
Hairy Woodpecker (1 holder)
Cosley Zoo
Greater Yellownape Woodpecker (1 holder)
San Diego Zoo (pierrei)
Golden-backed Woodpecker (1 holder)
Toledo Zoo and Aquarium
Pileated Woodpecker (2 holders)
Buttonwood Park Zoo
Minnesota Zoo
Northern Flicker (1 holder)
Cosley Zoo