Dr. John Kelly heads a project that tracks 150 heron/egret colonies in the greater Bay Area. He is with the Cypress Grove Research Center, a part of Audubon Canyon Ranch. Research how shown that a healthy colony reflects a healthy environment. In 2003, he appointed Petaluma Wetland Docents Len Nelson and Bob Dyer as site coordinators and field obervers for a new colony, directly across from Shollenberger Park and on property now owned by Dutra Materials. Colonies are protected from disturbance during the breeding season (February - August) under the the federal Migratory Bird Treaty Act.

2008 was the most productive year for the Shollenberger colony (designated colony #121), fledging 71 Great Egret, 2 Snowy Egret and 6 Great Blue Heron chicks. Nelson and Dyer observe the colony every two weeks during the nesting season and provide reports to Dr. Kelly. An attached photo shows just one sector of the colony as seen from Shollenberger Park, this one with 15 Great Egret nests. The colony had a total of 63 nests, for all species. Many park visitors and hundreds of local schoolchildren observe the colony with park docents providing viewing scopes, every spring.

The proposed Dutra asphalt and recycling plant now threatens the future of the colony. Dr. Kelly states that a buffer zone is required around colonies during the nesting season, and is especially important during the critical pair-bonding and nest formation period. For a 95% no-disturbing confidence this buffer zone should be about 650 feet - for a 50% confidence level, 165-200'. In the Dutra plan, the conveyer belt carrying materials from barges is only 125' away and a volunteer fire house between 50-75' away.

The closest regular source of background noise for the colony is presently the Petaluma Blvd. off-ramp about 200' from the colony. Dr. Kelly points out that tolerance reflects choices made by the birds when they choose a colony site. He states "...these sites may be subsequently abandoned in response to CHANGES in the frequency or intensity of human activity. Therefore...noise, artificial lights, conveyer activity...are likely to increase the risk of abandonment." These comments were submitted to the county in regards to the proposed Dutra project. There is more of an even chance, therefore, that the Dutra project will cause abandonment of this colony, in violation of federal law.

Other materials will be posted regarding serious hazards to human healthy and the Petaluma River by the proposed plant. The project is before the Sonoma County Board of Supervisors at 2 PM on February 3. Petitions are being passed around Petaluma for those who oppose the project to sign.

colonyAeara2009.jpg (276 KB, 48 downloads) One sector of Shollenberger Heron/Egret colony showing 15 Great Egret nests