The inquiries start casually. “Hey, I haven’t seen you in a while. How have you been?” But when Alex LaMond’s phone lights up with texts from her Brooklyn neighbors, she knows what’s coming.

Quickly, the conversations turn to chickens.

They ask after Agnes and Charlene and the other hens that jut across the brightly colored coop in the community garden where Ms. LaMond volunteers. And then comes the real point of the texts: eggs.

“Do you have any extra?” she said the neighbors ask. “People try anything they can to get the eggs.”

Across the United States, the spread of bird flu has sent egg prices that were already high soaring. The culling of flocks and subsequent grocery store and restaurant price markups on eggs have exasperated shoppers. In New York City, the egg shortage has injected a particular kind of chaos among the miles of sidewalks where supply is unreliable and prices vary wildly block to block.

In a city that values local knowledge and exclusivity, a new kind of power structure is emerging for anyone who has eggs or knows where to get them cheap, or even at all.

Signs of this dynamic were evident on a recent day at one Manhattan grocery store, where a worker passed the empty egg shelves, reached into her smock and handed a favorite customer a full carton.