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It was misty afternoon when Gaston Habets stepped out onto Mangini Ranch Educational Preserve. Earlier rains and persistent fog, which had been blocking out the sun, had turned the region’s hills green early this season.

Today, the land was getting a brief respite from the heaviest of the encroaching fog with the bright rays of the descending sun illuminating the land. It was the perfect time to get some work done.

Gaston was on a mission to put his newest creation for Save Mount Diablo to use; he was there to mount a small bluebird box.

Save Mount Diablo has been mounting bird boxes across our properties for years now, to support the recovery of their populations.

Gaston has big plans for Mount Diablo’s birds. He’s already installed two boxes at our Marsh Creek 7 property in addition to the one that he recently installed at Mangini Preserve.

His passion for birds has followed him home, where he has at least 16 boxes ready for installation, in a variety of sizes suitable for barn owls, kestrels, bluebirds, and chickadees.

In fact, it was a successful bluebird box installed above his mailbox that inspired Gaston to start working on these projects with us!

Gaston is well-versed in birds of the Netherlands. He’s always been interested in wildlife photography, as well as the optics of lenses, cameras, and microscopes (his degree is in microbiology).

After coming to California, he has been learning to identify all the new bird species, as well as learning from an online Cornell ornithology course about various bird behaviors. He’s a big fan of continued learning.

Gaston made the bluebird and chickadee boxes entirely by himself. The larger ones were ordered from Native Bird Connections before he took them apart to re-screw and re-glue them for a better seal.

Gaston first started volunteering with Save Mount Diablo by joining our American kestrel project.

Though there are now other types of boxes installed on our land, the kestrels remain a priority. Next, Gaston is planning to install a few kestrel boxes at Curry Canyon Ranch and Marsh Creek 7.

Save Mount Diablo Supports Kestrel Recovery

We’ve been installing bird boxes to support the Diablo region’s kestrel population for several years now. To date, we’ve installed 37 kestrel boxes!

American kestrels have been facing numerous threats, including habitat loss and invasive species, in addition to the 2025 bird flu epidemic, which caused the populations of many North American raptor species to nosedive.

In 2025, many of our boxes sat empty. But we still have plenty of reasons to hope for the full recovery of North America’s smallest falcon.

All in all, our work supporting Mount Diablo’s recovering kestrel population is paying off; over the years, at least 75 percent of these boxes have successfully served as habitat, giving kestrels a safe place to nest and raise their offspring.

The bird boxes are working.

How do we know which boxes are successful? The answer is wildlife cameras. Over the past few years, we’ve installed cameras so that we can observe how the birds are using the boxes.

These cameras help us understand which birds bring prey home, what they eat, how many young birds hatch, and when young birds fledge, all without interfering with the birds.

In 2025, we installed an additional 12 cameras on 12 boxes.

This year, we look forward to seeing how the kestrels and other birds use these new boxes.

Please reach out to Sean Burke at sburke@savemountdiablo.org if you would like information on how you can get involved and install bird boxes in your home or the surrounding open space.