Tree Swallow/Bluebird Nest Box Monitoring

On 5 April 2007, docents began monitoring 20 swallow boxes built by the late PWA docent Andy LaCasse. Over time, more boxes were added, some moved to better locations. Years have now passed since PWA began monitoring the Tree Swallows in Shollenberger Park and, since 2014, Ellis Creek Oxidation Ponds. In 2017, a few houses were moved out of Shollenberger to Ellis Creek where the houses are spread further apart with the hope that this would improve the mortality rate at the latter. Today there are 40 boxes being monitored which are spread over six designated areas in Ellis Creek and Shollenberger Park. There are also 20 boxes being monitored at Tolay Regional Park by PWA docents.

The swallows nesting in boxes at Shollenberger/Alman Marsh/Ellis Creek are Tree Swallows, Tachycineta bicolor. Western Bluebirds, Sialia mexicana, are also using some of the boxes.

PWA’s goals in monitoring these houses are:
Determine the usefulness of our nest box sites
Learn about the natural history and nesting results
Teach others about the importance of our nest boxes
Provide habitat for Tree Swallows and Western Bluebirds
Monitor, clean, and maintain the boxes to improve the odds of chicks fledging
Contribute to citizen science
Share data with interested parties

The boxes are monitored every 4-7 days using the protocols from the study Golondrinas de las Americas, which employs naturalists ranging from Alaska to Argentina. In 2024 PWA docents began to participate in a citizen science monitoring project through Cornell University Ornithology Lab. Docents form teams of two to share the monitoring duties and data entry for the season. Monitors are trained in the Cornell monitoring protocol.
If you are interested in getting involved, please join PWA and let the membership chair know you are interested in nest box monitoring. Our efforts to improve the Tree Swallow / Bluebird mortality rate is extremely interesting and is also challenging and rewarding , especially when one’s efforts culminate in good results.
If you have questions or want details on how these nests are monitored, contact our monitor chair, Linda Sheppard, lsheppard@petalumawetlands.org

As we begin using a new way to collect data, the reporting format will change beginning with the 2024 nesting season.