THE Bay Area is unmatched in its embrace of the urban backyard chicken trend. But raising chickens, which promises delicious, untainted eggs and instant membership in the local food movement, isn’t all it’s cracked up to be.

Chickens, it turns out, have issues.

They get diseases with odd names, like pasty butt and the fowl plague. Rats and raccoons appear out of nowhere. Hens suddenly stop laying eggs or never produce them at all. Crowing roosters disturb neighbors.

The problems get worse. Unwanted urban chickens are showing up at local animal shelters. Even in the best of circumstances, chickens die at alarming rates.

“At first I named them but now I’ve stopped because it’s just too hard,” said Sharon Jones, who started with eight chickens in a coop fashioned from plywood and chicken wire in the front yard of her north Berkeley home. She’s down to three.