Yes, but only #1-14. After the 15th one, no more.

Zebras are closely related to donkeys and yes, they both bark.

Based on the area code (Oklahoma - Tulsa vicinity) and the land survey info, I'm assuming this is an identifier sign for oil leases. They used native barking zebras to keep claim jumpers off their property/lease. Sadly the native species were extirpated sometime after 2008.