Sequoia Audubon Society
                              San Mateo County, California

SAS Cavity Nesters Recovery Program

Cavity Nesters Recovery Program

CNRP involves many volunteers in San Mateo County who establish and monitor nest box trails for cavity-nesting birds. During the breeding season, these boxes are checked weekly for parasitism, predation, number of eggs, nestlings, and number of young fledged. Then at the end of the nesting season, volunteers submit their results to us. We compile these results for the county and submit them to the statewide California Bluebird Recovery Program and other interested organizations.

Our program is immensely successful in helping native cavity-nesting species such as the Western Bluebird, Chestnut-backed Chickadee, Ash-throated Flycatcher, Violet-green Swallow and others. Cavity-nesting birds of prey such as Barn Owls, American Kestrels and Western Screech Owls also benefit.

This program is part of the California Bluebird Recovery Program, which is jointly sponsored by Audubon California and the North American Bluebird Society.

If you are interested in monitoring a nest box trail, contact our Programs Coordinator at for more information.

Click here for more information on monitoring and nest box plans.


by Don Yoder (Santa Clara Audubon Society)

A down-to-earth conservation effort - the larger the better - can make a difference! Over the years, bluebirds have lived and reproduced in California. However, development in rural areas has destroyed much of their preferred habitat. Now their numbers are declining and we must take action to reverse the trend and prevent their total disappearance. 

California is a state with wide variations in terrain, altitude and vegetation. There are many niches where bluebirds can be reestablished if cavities — nestboxes — are provided. Many people have not seen a bluebird in years in areas in which they used to be residents or frequent visitors.

There are many ways to help cavity-nesting species. While we particularly emphasize bluebird recovery, we welcome any cavity nester. All native species are a part of the natural scene and their preservation is of utmost importance to our own survival. We invite your inquiry and earnest participation.

We want to share the fun and excitement we experience when bluebird fledglings leave the nest to take their place among the trees and the grasslands.

As part of the state California Bluebird Recovery Program, a network of County Coordinators provides close contact with individuals who maintain their own nestbox trails. Questions and problems do arise and local help is usually available.

Participation by more people, the selection of good habitat, and the provision of proper boxes can make an impact on the survival rate and numbers of bluebirds. We are already seeing results throughout the State.

Our aims are to:

  • Enlist current bluebirders and recruit others who will help reestablish bluebirds in their normal habitat

  • Find typical habitat for the placement of nestboxes suitable for use by bluebirds

  • Secure monitors to care for the boxes and keep systematic records of the development of young birds during the nesting season

  • Record and analyze all annual summaries of nestbox records

  • Provide a forum (newsletter) through which fellow trail operators can exchange information

  • Secure help in solving problems encountered in the field




  • Building Nest Boxes and Nest Box Kits as a Group Activity (PDF) (by Charles Wade) includes plans and complete information. Use these plans to build your own nest box for songbirds such as Chickadees, Swallows and Bluebirds, plus Wood Ducks.

  • Build a Bluebird Nest Box (PDF) (by Lee Pauser) provides information needed to build a hanging bluebird nest box specifically designed for the Western Bluebird. These instructions include plans to cut one sheet of plywood into parts for nine boxes (view the plans to cut three sheets of plywood into parts for 30 boxes (PDF)). This design can be scaled for other species and modified to produce a mounted nest box. Features a compilation of designs that cultivate successful nesting.

  • Hanging Nest Box Retriever (by Lee Pauser) instructions to build your own extendable tool for fetching nest boxes in trees.

  • Build a Barn Owl nest box (by Charles G. Wade, Lee Pauser, and David Altknecht). This plan provides information on the why, where, and how regarding building a Barn Owl nest box. This design is modeled after the design developed by Steve Simmons of Merced, California, who has personally fledged thousands of Barn Owls.

  • Pulley System to Raise and Lower Large Nest Boxes (PDF) (by Lee Pauser). Accessing large nest boxes is a problem of varying magnitude. To address this issue, Lee Pauser developed a pulley system to easily access a nest box mounted on a 2" ID galvanized metal pipe. Specifically, the system enables the raising and lowering of a large pole-mounted nest box from the ground thereby negating the need to port a ladder to the box. A lock secures the box in its raised position. The pulley system is most beneficial when used with boxes that are remote and accessible only by foot.


Sequoia Audubon would like to express our appreciation for the cooperation and resources provided by the Santa Clara Valley Audubon Society.

2021 S.A.S.; or content originators.