MONTEREY — Native coastal oak trees in and around Monterey are dying at a rate that is concerning urban foresters and neighborhood organizations.

Justin Prouty, interim urban forester for the city of Monterey, confirmed that there is concern over the number of oaks being lost. Most are succumbing to a suspected but unconfirmed disease.

Local oaks, particularly natives like the coastal oaks, aren’t just part of what makes cities aesthetically livable. They are important in their role as part of an interdependent ecosystem. For example, an entire category of songbirds, called “cavity nesters,” depend on the holes left behind when limbs of oaks break off. Those holes make ideal nesting sites for species such as western bluebirds, chestnut-backed chickadees and white-breasted nuthatches, all native to Central California’s coastal regions.

Birds, in turn, are important to other aspects of an ecosystem, such as controlling insects and spreading plant seeds. Bluebird numbers have been falling for decades as a direct result of the loss of nesting habitat, according to both the Audubon Society and the Cornell University Lab of Ornithology, which maintains a database of bird populations.

At first mention of dying oaks it’s natural to jump to the conclusion that Monterey is falling victim to sudden oak death that has killed more than 1 million oak trees from Monterey to Humboldt County in the past decade. And certainly the fungus-like pathogen that causes sudden oak death is not being discounted. But there is an emerging threat from a similar fungus that causes a condition called foamy bark cankers.

“It’s relatively new and it’s affecting a lot of trees in Monterey County,” Prouty said. “We’re concerned.” He cautioned, however, that the exact cause cannot be confirmed until further testing is done.

That’s exactly what Richard Ruccello would like to see done. The president of Casanova Oak Knolls Neighborhood Association in north Monterey, Ruccello has lived in the neighborhood for decades, in fact, since the Kennedy administration. He started noticing a significant die-off of oak trees and heard many similar stories from some of the roughly 1,500 neighbors.

He began documenting the loss and reading the research on oak mortality. Suspecting there was more at play than Mother Nature, Ruccello took advantage of a city of Monterey effort called the Neighborhood Improvement Program. The way it works is projects are recommended by any number of neighborhood groups to a Neighborhood Improvement Program committee, which then votes, ranks and then makes recommendations to the City Council to receive funding.

On Friday, Ruccello said he learned that his project of testing the trees to identify the right pathogen garnered second to the most votes by committee members. It will be going to the City Council by late September or early October.

The fungus is carried by the western oak bark beetle that burrows into the oaks and other species of trees and carries the spores with them, Prouty explained. They cause what he calls “girdling,” where the flow of water and nutrients are restricted. There is no known pest management system to control the beetle. So when the fungus strikes, the limbs or the entire tree must be removed. Even that is open to debate as to how effective it is, Prouty said.

But while the fungus is dangerous to trees, it is also getting a lot of help. The years of drought that is just now starting to turn around has weakened oak trees. Weakened trees allow them to be more susceptible to infestations.

“Any tree can be attacked by beetles, but healthy trees can fight off disease,” Prouty said. “Unfortunately the drought has dealt a death blow to many trees.”

Cal Fire agrees. Between 2012 and 2017 over 100 million trees died due to many years of drought that weakened the trees and left millions of acres of forestland highly susceptible to insect attacks, according to a Cal Fire report. But the good news is the recent rainy winters.are helping to taper off the drought stress trees have suffered.

With scientists predicting that climate change could produce more intense and longer droughts, the current die-off could just be the proverbial canary in the birdcage, or in this case, the bluebird in the oak tree.