The Cathedral of Learning’s feathered residents have welcomed a new addition to the nest.

The National Aviary says the peregrine falcons — Carla and her mate Ecco — saw the egg arrive Sunday afternoon. They live on the side of the cathedral.

It’s the first of about four eggs total, experts at the Aviary predict.

Aviary officials say Carla could lay one egg every 48 hours or so until the clutch is complete. Once the last egg is laid, she will start to incubate the clutch. In the meantime, the eggs can be safely left uncovered. The eggs have strong temperature tolerances, meaning they can endure the inconsistent climate changes brought by the spring season.

Carla and Ecco will both incubate the eggs, with Carla handling about two-thirds of the work Ecco one-third. It will be a little over a month for the eggs to begin hatching, officials said.