UC Davis Health System

04/15/2026 | Press release | Distributed by Public on 04/15/2026 14:02

California Tower’s first patients arrive early — and have wings

(SACRAMENTO)

By the time California Tower opens its doors to patients in 2030, its first residents will already have taken flight.

Four years before the massive new medical facility is scheduled to welcome patients, four hummingbirds quietly claimed space inside the tower, transforming an active construction site into an unexpected nursery and giving new meaning to the idea of patient-centered care.

Since mid-February, two mother hummingbirds have nested inside the California Tower as it rises skyward, each laying two eggs. All four hatchlings survived - a rare and heartening outcome - with the first pair already airborne and the second expected to leave the nest by mid-April.

The discovery unfolded on February 13, when construction teams spotted a tiny nest on Level 6 at the tower's north end near the water tank. The nest, improbably delicate against the industrial backdrop, was built inside the top of a Ziplock bag attached to a wire hanger support.

Zippy's nest is discovered in a Ziplock bag at the California Tower on Level 6.

All trade workers and staff receive training on how to respond when wildlife is encountered, particularly protected species such as hummingbirds.

To protect the birds while keeping the project moving, a team of biologists from ICF, contracted by UC Davis, partnered closely with the project team to ensure the birds were properly protected and that flight paths remained clear.

The mother hummingbird was quickly nicknamed "Zippy," a nod to her use of unconventional building materials and her quick speed.

"She couldn't have picked a more unlikely place," said Christina Middleton, project manager with Cambridge CM, "but she picked it well."

Zippy laid two eggs, and both hatchlings survived and matured. Workers named the fledglings "Fragnet," a term for a construction scheduling delay, and "Delay-la," an affectionate nod to the brief pause required to keep them safe. By March 31, the young hummingbirds had grown strong enough to leave the nest and fly away from the tower.

Zippy feeds her two chicks, Fragnet and Delay-la, inside the nest.

But before they departed, the team was met with another surprise: it seems Zippy shared her secret.

On March 17, workers discovered a second hummingbird nest on Level 4, also tucked inside a Ziplock bag attached to a wire hanger support. This nest sat near the emergency department circle drive - an area buzzing with activity and in the middle of extensive siding installation.

The second mother, named "Ziplock," posed a more complex challenge.

A newly discovered nest is seen on Level 4 of the California Tower.

Unlike the first nest, exterior construction in this area was already well underway. The biologists again worked closely with the team, led by UC Davis Environmental Planning Liaison Alex Tremblay. As with the first nest, workers immediately followed established bird-mitigation protocols.

The biologists evaluated Ziplock's flight path, identified a buffer zone, and helped determine which sections of the siding (also known as curtainwall) installation could proceed without disturbing the nest.

Two eggs rest inside Ziplock's nest.

Installation in the immediate flight path was moved to other areas as the team identified ways to work around the area and continue progress. Then, for three days, the biologist remained on site to monitor conditions - tracking noise levels, activity and proximity to ensure the mother and nest were not disturbed.

The eggs hatched on March 31. The two fledglings are healthy and growing, and they are expected to leave the nest in mid-April. They have not yet been named.

Ziplock relaxes near her nest during the curtain wall installation on Level 4.

The male hummingbirds, meanwhile, have played their own role by guarding nearby food sources while the mothers remained at their nests.

Zippy relied on flowering plants outside the Cancer Center for food, while Ziplock has been spotted feeding in the landscaped traffic circle in front of the medical center.

Why would hummingbirds choose a towering construction site over quieter trees or eaves?

Project leaders and biologists have a theory: Constant noise and activity may deter natural predators, creating an unexpectedly safe nesting environment.

The first nest, an intricate, gossamer structure woven from spiderwebs and plant fibers, was carefully preserved after the fledglings left. Project leaders hope to include it in the building's time capsule, a lasting reminder that life finds ways to thrive even during large-scale construction.

Zippy's nest is displayed after she and her young have left it.

For workers on the project, the hummingbirds offered more than a schedule adjustment. They became a daily reminder of purpose.

"Watching everyone slow down, problem-solve and protect something so small while building something so big - it really stuck with people," Middleton said.

As the California Tower construction continues and prepares for its future role in patient care, its earliest success story has already taken flight, four tiny lives nurtured through collaboration, care and an unusual Ziplock-bag nursery high above the ground.

While the tower's first human patients are still to come, its first residents have already shown what's possible when compassion extends beyond blueprints.

UC Davis Health System published this content on April 15, 2026, and is solely responsible for the information contained herein. Distributed via Public Technologies (PUBT), unedited and unaltered, on April 15, 2026 at 20:02 UTC. If you believe the information included in the content is inaccurate or outdated and requires editing or removal, please contact us at [email protected]