photo: Paul Chinn, San Francisco Chronicle

A grisly scene emerged out of the San Francisco Bay Area when tree trimmers in Oakland were caught feeding downed branches full of Black-crowned Night Heron nests and chicks directly into a woodchipper. The San Francisco Chronicle reports:

Officials at the downtown post office ordered nearby trees trimmed Saturday because nesting birds were defecating on the mail trucks.

The result, witnesses said, was a feathery massacre that ended with nests – and baby birds – fed through a wood chipper, hysterical neighbors protesting in the street, and a call to Oakland police officers, who ordered the trimmers to stop.

Now, state and federal wildlife officials are investigating the matter, because the nest destruction and bird deaths may have violated the U.S. Migratory Bird Treaty Act.

“I’m devastated. That someone could do that without even looking to see if there are nests, could have so little empathy … it’s heart wrenching,” said Stephanie Benavidez, Oakland’s supervising naturalist. “The public was incensed, rightfully.”

But everyone agrees the large birds can be messy. The sidewalks around 13th and Alice streets, for example, are often a white slick of guano. And the mail trucks parked in the lot there bear the brunt of it.

Enter Campos Tree Service, a family-owned operation based in Walnut Creek. Postal officials hired Campos to trim the city-owned trees that housed the offending birds.

On Saturday, crews sawed off branches on four trees, setting aside a few babies but otherwise sending nests and chicks toppling 25 feet to the ground before they were then fed to the wood chipper, witnesses said.

Residents in the neighborhood brought surviving chicks into the care of wildlife rehabilitators. The five saved babies were ultimately transferred to our San Francisco Bay center in Fairfield, where they’re currently being taken care of in a warm incubator. In addition to scrapes and bruises on the birds, one orphan underwent surgery to repair a fractured mandible.